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MMBasic Language Manual

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2. Implementation Characteristics Maximum length of a command line is 255 characters Maximum length of a variable name or a label is 32 characters Maximum number of dimensions to an array is 8 Maximum number of arguments to commands that accept a variable number of arguments is 50 Maximum number of user defined subroutines and functions combined 64 Numbers are stored and manipulated as single precision floating point numbers The maximum number that can be represented is 3 40282347e 38 and the minimum is 1 17549435e 38 The range of integers whole numbers that can be manipulated without loss of accuracy is 16777100 Maximum string length is 255 characters Maximum line number is 65000 Maximum length of a file pathname including the directory path is 255 characters Maximum number of files simultaneously open is 10 on the SD card and one on the internal flash drive A Maximum SD card size is 2GB formatted with FAT16 or 2TB formatted with FAT32 Size of the internal flash drive A is 212KB Maximum size of a loadable video font is 64 pixels high x 255 pixels wide and 256 characters License MMBasic is Copyright 2011 2012 Geoff Graham http geoffg net The compiled object code the hex file is free software you can use or redistribute it as you please This program is distributed in the hope that it will be useful but WITHOUT ANY WARRANTY without even the implied warranty of MERCHANTABILITY or FITNESS FOR A P
3. are processed with a left to right precedence as they occur on the program line Arithmetic operators 3 Exponentiation MOD Multiplication division integer division and modulus remainder Addition and subtraction Logical operators NOT logical inverse of the value on the right lt lt gt lt amp lt Inequality less than greater than less than or equal to less than or gt gt equal to alternative version greater than or equal to greater than or equal to alternative version equality AND OR XOR Conjunction disjunction exclusive or The operators AND OR and XOR are bitwise operators For example PRINT 3 AND 6 will output 2 The other logical operations result in the number 0 zero for false and 1 for true For example the statement PRINT 4 gt 5 will print the number zero on the output and the expression A 3 gt 2 will store 1 in A The NOT operator is highest in precedence so it will bind tightly to the next value For normal use the expression to be negated should be placed in brackets For example IF NOT A 3 OR A 8 THEN MMBasic Language Manual Page 7 String operators Join two strings oOo lt gt eS lt Inequality less than greater than less than or equal to less than or gt gt equal to alternative version greater than or equal to greater than or equal to alternative version equality
4. nbr See the OPEN command WRITE can be replaced by the PRINT command MMBasic Language Manual Page 31 Appendix A Serial Communications Maximite family only Two serial ports are available for asynchronous serial communications four on the DuinoMite They are labelled COM1 COM2 etc and are opened in a manner similar to opening a file After being opened they will have an associated file number like an opened disk file and you can use any commands that operate with a file number to read and write to from the serial port A serial port is also closed using the CLOSE command The following is an example OPEN COM1 4800 AS 5 PRINT 5 Hello Data INPUTS 20 5 CLOSE 5 open the first serial port with a speed of 4800 baud send the string Hello out of the serial port get up to 20 characters from the serial port close the serial port The OPEN Command A serial port is opened using the command OPEN comspec AS fnbr The transmission format is fixed at 8 data bits no parity and one stop bit fnbr is the file number to be used It must be in the range of 1 to 10 The is optional comspec is the communication specification and is a string it can be a string variable specifying the serial port to be opened and optional parameters It has the form COMn baud buf int intlevel FC OC where e m is the serial port number for either COM1 or COM2 e
5. C slave device with the optional ability to send some rcvlen rcvbuf sendlen data first senddata sendata addr is the slave i2c address note that 10 bit addressing is not supported option is a number between 0 and 3 1 keep control of the bus after the command a stop condition will not be sent at the completion of the command 2 treat the address as a 10 bit address 3 combine and 2 hold the bus and use 10 bit addresses revlen is the number of bytes to receive rcvbuf is the variable to receive the data this is a one dimensional array or if revlen is 1 then this may be a normal variable The array subscript does not have to be zero and will be honoured also bounds checking is performed Optionally you can specify data to be sent first using sendlen and senddata These parameters are used the same as in the I2CSEND command ie senddata can be a constant an array or a string variable Examples I2CRCV amp h6f 1 1 avar I2CRCV amp h f 1 5 anarray 0 I2CRCV amp h f 1 4 anarray 2 3 amp h12 amp h34 amp h89 I2CRCV amp h f 1 3 anarray 0 4 anotherarray 0 The automatic variable MM I2C will hold the result of the transaction MMBasic Language Manual Page 35 I2C Slave Mode Commands I2CSEN addr mask Enables the C module in slave mode option send_int rcv_int addr is the slave i2c address mask is the address mask
6. Long programs with or without line numbers can be sent via USB to MMBasic using the XMODEM command Maximite only or the AUTO command Program and Data Storage In DOS the drive letters are as supported by Windows On the Maximite two drives are available for storing and loading programs and data e Drive A is a virtual drive using the PIC32 s internal flash memory and has a size of 212KB e Drive B is the SD card if connected It supports MMC SD or SDHC memory cards formatted as FAT16 or FAT32 with capacities up to the largest that you can purchase MMBasic Language Manual Page 3 File names must be in 8 3 format prefixed with an optional drive prefix A or B the same as DOS or Windows Long file names and directories are not supported The default drive is B and this can be changed with the DRIVE command On the Maximite MMBasic will look for a file on startup called AUTORUN BAS in the root directory of the internal flash drive A then the SD card B If the file is found it will be automatically loaded and run otherwise MMBasic will print a prompt gt and wait for input Note that the video output will go blank for a short time while writing data to the internal flash drive A This is normal and is caused by a requirement to shut off the video while reprogramming the memory Storage Commands and Functions A program can be saved to either drive using the SAVE command It can be reloa
7. SPI 11 12 13 amp HE4 M 2 12 Transmission Format The most significant bit is sent and received first The format of the transmission can be specified by the mode as follows Mode CPOL CPHA Description 0 0 0 Clock is active high data is captured on the rising edge and output on the falling edge 1 0 1 Clock is active high data is captured on the falling edge and output on the rising edge 2 1 0 Clock is active low data is captured on the falling edge and output on the rising edge 3 1 1 Clock is active low data is captured on the rising edge and output on the falling edge For a more complete explanation see http en wikipedia org wiki Serial_Peripheral_Interface_Bus MMBasic Language Manual Page 39 I O Pins Before invoking this function the rx pin must be configured as an input using the SETPIN command and the tx and clk pins must be configured as outputs either normal or open collector again using the SETPIN command The clock pin should also be set to the correct polarity using the PIN function before the SETPIN command so that it starts as inactive The SPI enable signal is often used to select a slave and prime it for data transfer This signal is not generated by this function and if required should be generated using the PIN function on another pin The SPI function does not take control of the I O pins like the serial and I C
8. 8 Digital output all pins 9 Open collector digital output to 5V pins 11 and above In this mode the function PINO will also return the output value In the Maximite implementation the highest pin number is 20 and in the UBW32 version it is 50 Note that on the UBW32 pin 48 is shared with the white LED pin 49 is shared with the green LED and the program pushbutton is connected to pin 50 In the DuinoMite version pins 8 to 12 as well as 19 and 20 are unavailable See the function PIN for reading inputs and the statement PINO for outputs See the command below if an interrupt is configured MMBasic Language Manual Page 22 SETPIN pin cfg target MM Will configure pin to generate an interrupt according to cfg 0 Not configured or inactive 6 Interrupt on low to high input change 7 Interrupt on high to low input change all pins all pins The starting line number of the interrupt routine is specified in the third parameter target which can be a line number or label This mode also configures the pin as a digital input so the value of the pin can always be retrieved using the function PINO See also IRETURN to return from the interrupt SETTICK period target MM This will setup a periodic interrupt or tick The time between interrupts is period milliseconds and target is the line number or label of the interrupt routine See also IRETURN to return from the interrupt
9. Forces the sign to be shown for positive numbers space Causes a positive value to display a space for the sign Negative values still show the sign width is the minimum number of characters to output less than this the number will be padded more than this the width will be expanded precision specifies the number of fraction digits to generate with an e or f type or the maximum number of significant digits to generate with a g type If specified the precision must be preceded by a dot type can be one of g Automatically format the number for the best presentation f Format the number with the decimal point and following digits e Format the number in exponential format If uppercase G or F is used the exponential output will use an uppercase E If the format specification is not specified g is assumed Examples format 45 will return 45 MMBasic Language Manual Page 26 format 45 g will return 45 format 24 1 g will return 24 1 format 24 1 f will return 24 100000 format 24 1 e will return 2 410000e 01 format 24 1 09 3f will return 00024 100 format 24 1 3f will return 24 100 format 24 1 9 3f will return 24 100 HEX number MM Returns a string giving the hexadecimal base 16 value for the number DOS INKEY MM Checks the keyboard and USB input buffers and if there is on
10. MM Will return the number of bytes waiting in the receive buffer of a serial port ie COM1 or COM2 that has been opened as nbr The is optional LOF nbr MM Will return the space in bytes remaining in the transmit buffer of a serial port ie COM1 or COM2 that has been opened as nbr The is optional LOG number MM Returns the natural logarithm of the argument number DOS MMBasic Language Manual Page 27 LCASE S string MM Returns string converted to lowercase characters DOS MIDS string start MM Returns a substring of string beginning at start position in string and position in string number DOS continuing for number of chars bytes If number of chars is omitted of chars the returned string will extend to the end of string OCT number MM Returns a string giving the octal base 8 representation of number DOS PEEK hiword loword MM Will return a byte within the PIC32 virtual memory space hiword is DOS the top 16 bits of the address while loword is the bottom 16 bits See the POKE command for notes and warnings related to memory access PI MM Returns the value of pi DOS PIN pin MM Returns the value on the external I O pin Zero means digital low 1 means digital high and for analogue inputs it will return the measured voltage as a floating point number Frequ
11. The period can range from 1 to 4294967295 mSec about 49 days This interrupt can be disabled by setting line to zero ie SETTICK 0 0 SOUND freq or SOUND freq dur or SOUND freq dur duty MM Generate a single tone of freq between 20 Hz and 1 MHz for dur milliseconds The sound is played in the background and does not stop program execution If dur is not specified the sound will play forever until turned off If dur is zero any active SOUND statement is turned off If no SOUND statement is running a dur of zero has no effect duty is the optional duty cycle of the waveform in percent If it is close to zero the output will be a narrow positive pulse if 50 a square wave will be generated and if close to 100 it will be a very wide positive pulse If it is not specified the duty cycle will default to 50 Setting the duty cycle allows the sound output to be used as a Pulse Width Modulation PWM output for driving analogue circuits The signal will be available at the sound connector and the voltage divider on this output should be removed so that the full signal level is available The frequency of the output is locked to the PIC32 crystal and is very accurate and for frequencies below 100 KHz the duty cycle will be accurate to 0 1 SUB xxx arg arg2 lt statements gt lt statements gt END SUB MM DOS Defines a callable subroutine This is the
12. dOO and Doo refer to the same variable There are two types of variable numeric which stores a floating point number eg 45 386 and string which stores a string of characters eg Tom String variable names are terminated with a symbol eg name while numeric variables are not Variable names and labels can start with an alphabetic character or underscore and can contain any alphabetic or numeric character the period and the underscore _ They may be up to 32 characters long A variable name or a label must not be the same as a function or one of the following keywords THEN ELSE GOTO GOSUB TO STEP FOR WHILE UNTIL LOAD MOD NOT AND OR XOR Eg step 5 is illegal as STEP is a keyword In addition a label cannot be the same as a command name Constants Numerical constants may begin with a numeric digit 0 9 for a decimal constant amp H for a hexadecimal constant amp O for an octal constant or amp B for a binary constant For example amp B1000 is the same as the decimal constant 8 Decimal constants may be preceded with a minus or plus and may terminated with E followed by an exponent number to denote exponential notation For example 1 6E 4 is the same as 16000 String constants are surrounded by double quote marks Eg Hello World Operators and Precedence The following operators in order of precedence are recognised Operators that are on the same level for example and
13. 3 0 and later the use of line numbers is optional MMBasic will still run programs written using line numbers but it is recommended that new programs avoid them The structure of a program line is line number label command arguments command arguments Instead of using a line number a label can be used to mark a line of code A label has the same specifications length character set etc as a variable name but it cannot be the same as a command name When used to label a line the label must appear at the beginning of a line but after a line number if used and be terminated with a colon character Commands such as GOTO can use labels instead of line numbers to identify the destination in that case the label does not need to be followed by the colon character For example GOTO xxxx xxxx PRINT We have jumped to here MMBasic finds a label much faster than a line number so labels are recommended for new programs Multiple commands separated by a colon can be entered on the one line as in INPUT A PRINT B On the Maximite you can use the EDIT command to edit programs You can use the arrow keys to move around the program and keys such as Home End Page Up and Down will do what you expect The editor will allow you to insert blank lines and indent lines for improved readability It will work using an attached video screen VGA or composite and over USB with a VT100 compatible terminal emulator Tera Term is recommended
14. STEP increment MM DOS Initiates a FOR NEXT loop with the counter initially set to start and incrementing in increment steps default is 1 until counter equals finish The increment must be an integer but may be negative See also the NEXT command MMBasic Language Manual Page 14 FUNCTION xxx arg1 MM Defines a callable function This is the same as adding a new function to arg2 DOS MMBasic while it is running your program lt statements gt xxx is the function name and it must meet the specifications for naming lt statements gt a variable arg1 arg2 etc are the arguments or parameters to the XXX lt return value gt function END FUNC HON To set the return value of the function you assign the value to the function s name For example FUNCTION SQUARE a SQUARE a a END FUNCTION Every definition must have one END FUNCTION statement When this is reached the function will return its value to the expression from which it was called The command EXIT FUNCTION can be used for an early exit You use the function by using its name and arguments in a program just as you would a normal MMBasic function For example PRINT SQUARE 56 8 When the function is called each argument in the caller is matched to the argument in the function definition These arguments are available only inside the function Functions can be called w
15. expert users only The PIC32 maps all control registers flash program memory and volatile RAM memory into a single address space so there is no need for INP or OUT commands The PIC32MX5XX 6XX 7XX Family Data Sheet lists the details of this address space while the source code will provide the symbolic names used in the firmware and the Maximite map file produced after a successful compile will list the addresses of these symbols These addresses will change with each version of the firmware so programs should use the predefined variable MM VER to determine the currently running version WARNING If you use this facility to access an invalid memory address the MIPS CPU will throw an exception which causes the processor to reset and clear all memory To see this effect try POKE 0 0 0 PRINT expression L expression etc MM DOS Outputs text to the screen Multiple expressions can be used and must be separated by either a e Comma which will output the tab character e Semicolon which will not output anything it is just used to separate expressions e Nothing or a space which will act the same as a semicolon A semicolon at the end of the expression list will suppress the automatic output of a carriage return newline at the end of a print statement When printed a number is preceded with a space if positive or a minus if negative but is not followed by a space Integers whole numbers are printed
16. expression MM Assigns the value of expression to the variable LET is automatically DOS assumed if a statement does not start with a command LINE x1 y1 x2 y2 MM Draws a line or box on the video screen x1 y1 and x2 y2 specify the Lc B F beginning and end points of a line c specifies the displayed pixel 0 off 1 on 1 invert and defaults to on if not specified x1 yl is optional and if omitted the last drawing point will be used The optional B will draw a box with the points x1 y1 and x2 y2 at opposite corners The optional BF will draw a box as B and fill the interior See page 5 for a definition of the graphics coordinates LINE INPUT prompt MM Reads entire line from the keyboard into string variable If specified string variable DOS the prompt will be printed first Unlike INPUT LINE INPUT will read a whole line not stopping for comma delimited data items A question mark is not printed unless it is part of prompt LINE INPUT nbr MM Same as above except that the input is read from a file previously opened string variable DOS for INPUT as nbr See the OPEN command LIST MM Lists all lines in a program line or a range of lines LIST line DOS Tf lastline is used it will start with the first line in the program If LIST lastline startline is used it will list to the end of the program LIST firstline LIST firstline lastline MMBasic Languag
17. floating point number Two serial ports are supported with speeds up to 19200 baud with configurable buffer sizes and optional hardware flow control The serial ports are opened using the OPEN command and any command or function that uses a file number can be used to send and receive data See Appendix A for a full description Communications to slave or master devices on an I C bus is supported with eight commands see Appendix B for a full description MMBasic fully supports bus master and slave mode 10 bit addressing address masking and general call as well as bus arbitration ie bus collisions in a multi master environment The Serial Peripheral Interface SPI communications protocol is supported with the SPI command See Appendix D for the details A high performance Pulse Width Modulation PWM output is also available by reusing the sound connector and specifying an optional duty cycle parameter to the SOUND command The Dallas 1 Wire protocol is also supported See Appendix C for details Timing not DOS You can get the current date and time using the DATE and TIME functions and you can set them by assigning the new date and time to them If not set the calendar will start from midnight 1 Jan 2000 on power up You can freeze program execution for a number of milliseconds using PAUSE MMBasic also maintains an internal stopwatch function the TIMER function which counts up in milliseconds You can reset the timer to zero or any
18. form HH MM SS in 24 hour notation For example 14 30 00 The internal clock calendar will keep track of the time and date including leap years The time is set to midnight on power up To set the time use the command TIME TIMER MM Returns the elapsed time in milliseconds eg 1 1000 of a second since DOS reset If not specifically reset this count will wrap around to zero after 49 days The timer is reset to zero on power up and you can also reset it by using TIMER as a command UCASE3S string MM Returns string converted to uppercase characters DOS MMBasic Language Manual Page 29 VAL string MM DOS Returns the numerical value of the string If string is an invalid number the function will return zero This function will recognise the amp H prefix for a hexadecimal number amp O for octal and amp B for binary MMBasic Language Manual Page 30 Obsolete Commands and Functions These commands and functions are only included to assist in converting programs written for Microsoft BASIC For new programs the corresponding commands in MMBasic should be used The centre column specifies the platform MM is Maximite family DOS is the Windows version Square brackets indicate that the parameter or characters are optional IF condition THEN linenbr mm For Microsoft compatibility a GOTO is assumed if the THEN statement is DOS fol
19. is 48 characters The prompt is reset to the default gt on power up but you can automatically set it by saving the following example program as AUTORUN BAS on the internal flash drive A 10 OPTION PROMPT My prompt 20 NEW OPTION Fnn string MM Sets the programmable function key Fnn to the contents of string Fnn is the function key F1 to F12 Maximum string length is 12 characters string can also be an expression which will be evaluated at the time of running the OPTION command This is most often used to append the ENTER key chr 13 or double quotes chr 34 For example OPTION F1 RUN CHR 13 OPTION F6 SAVE CHR 34 OPTION F10 ENDIF Normally these commands are included in an AUTORUN BAS file see OPTION PROMPT for an example OPTION USB OFF MM Turn the USB output off and on This disables enables the output from or the PRINT command from being sent out on the USB interface It does OPTION USB ON not affect the reception of characters from the USB interface Normally this is used when a program wants to separately display data on the USB and video interfaces This option is always reset to ON at the command prompt OPTION VIDEO OFF MM VIDEO OFF prevents the output from the PRINT command from being or displayed on the video output VGA or composite The VIDEO ON OPTION VIDEO ON option will revert to the normal action Normally this is used when a program wants to separately displ
20. keys are Left Right arrows Up Down arrows Moves the cursor within the line Moves the cursor up or down a line Page Up Down Move up or down a page of the program Home End Moves the cursor to the start or end of the line A second Home End will move to the start or end of the program Delete Delete the character over the cursor This can be the line separator character and thus join two lines Backspace Delete the character before the cursor Insert Will switch between insert and overtype mode Escape Key Will close the editor without saving confirms first Will save the edited text and exit Will save exit and run the program Function Key 1 Function Key 2 Function Key 3 Will invoke the search function SHIFT F3 Function Key 4 Will repeat the search using the text entered at F3 Will mark text for cut or copy see below Function Key 5 CTRL F When in the mark text mode entered with F4 the editor will allow you to use the arrow keys to highlight text which can be deleted cut to the clipboard or simply copied to the clipboard The status line will change Will paste text previously cut or copied Will insert a file into the program being edited MMBasic Language Manual Page 12 to indicate the new functions of the function keys While the full screen editor is running it will override the programmable function keys F1 to F5 When the editor exits all programmable functions will be restored T
21. length arg3 arg4 The bytes can be supplied as four separate numbers arg arg4 or as four elements of array starting at index x See the command NUM2BYTE for the reverse of this function MMBasic Language Manual Page 37 Appendix C 1 Wire Communications Maximite family only The 1 Wire protocol was invented by Dallas Semiconductor to communicate with chips using a single signalling line It is mostly used in communicating with the DS18B20 and DS18S20 temperature measuring chips This implementation was developed for MMBasic by Gerard Sexton There are four commands that you can use OWRESET pin presence OWWRITE pin flag length data data OWREAD pin flag length data data OWSEARCH pin srchflag ser ser Where pin the MMBasic I O pin to use presence an optional variable to receive the presence pulse 1 device response 0 no device flag a combination of the following options 1 send reset before command 2 send reset after command 4 only send recv a bit instead of a byte of data 8 invoke a strong pullup after the command the pin will be set high and open drain disabled length length of data to send or receive data data to send or receive srchflag a combination of the following options 1 start a new search 2 only return devices in alarm state 4 search for devices in the requested family first byte of ser 8 skip the current device family and ret
22. number MM Returns the sine of the argument number in radians DOS SPACE number MM Returns a string of blank spaces number bytes long DOS SPI rx tx clk data MM Sends and receives a byte using the SPI protocol with MMBasic as the speed master ie it generates the clock rx is the pin number for the data input MISO tx is the pin number for the data output MOSI clk is the pin number for the clock generated by MMBasic CLK data is optional and is an integer representing the data byte to send over the data output pin If it is not specified the tx pin will be held low speed is optional and is the speed of the clock It is a single letter either H M or L where H is 500 kHz M is 50 kHz and L is 5 kKHz Default is H See Appendix D for a full description SQR number MM Returns the square root of the argument number DOS STR number MM Returns a string in the decimal base 10 representation of number DOS STRING number ascii MM Returns a string number bytes long consisting of either the first character valuelstring DOS of string or the character representing the ASCII value ascii value TAB number MM Outputs spaces until the column indicated by number has been reached DOS TAN number MM Returns the tangent of the argument number in radians DOS TIME MM Returns the current time based on MMBasic s internal clock as a string in DOS the
23. other number by assigning a value to the TIMER Using SETTICK you can setup a tick which will generate a regular interrupt with a period from one millisecond to over a month See Interrupts below Interrupts not DOS Any external I O pin can be configured to generate an interrupt using the SETPIN command with up to 21 interrupts including the tick interrupt active at any one time Interrupts can be set up to occur on a rising or falling digital input signal and will cause an immediate branch to a specified line number or label similar to a MMBasic Language Manual Page 4 GOSUB The target can be the same or different for each interrupt Return from an interrupt is via the IRETURN statement All statements including GOSUB RETURN can be used within an interrupt If two or more interrupts occur at the same time they will be processed in order of pin numbers ie an interrupt on pin 1 will have the highest priority During processing of an interrupt all other interrupts are disabled until the interrupt routine returns with an IRETURN During an interrupt and at all times the value of the interrupt pin can be accessed using the PINQ function A periodic interrupt or regular tick with a period specified in milliseconds can be setup using the SETTICK statement This interrupt has the lowest priority Interrupts can occur at any time but they are disabled during INPUT statements If you need to get input from the keyboard while s
24. program that emulates the old fashioned VT 100 terminal over a serial communications link There are quite a few free emulators that you can use but I recommend Tera Term 1 You should download Tera Term from http en sourceforge jp projects ttssh2 releases and install it These instructions are based on version 4 71 Make sure that the USB cable is plugged into your PC and that you know the COM number 3 When you run Tera Term for the first time you will get a dialog box asking you to select the type of connection Select serial and select the correct COM number You should then see the MMBasic prompt as shown below Ml COM13 9600baud Tera Term VT acae File Edit Setup Control Window Help UBW32 MMBasic Version 2 7 Copyright 2011 Geoff Graham gt 4 Before you start using Tera Term you need to make a few changes to the setup Select Setup gt Terminal Set the terminal size to 80 x 36 Untick the tick box labelled term size win size Tick the box labelled auto window resize Select Setup gt Serial Port Make sure that the port matches the COM number representing the Maximite In the box for the transmit delay msec line enter 50 Leave the other box with zero in it You do not have to bother with the baud rate or any other settings Select Setup gt Save Setup Save the setup as TERATERM INI in the Tera Term installation directory overwriting the file there MMBasic Language Manual Page 43
25. the send and receive will complete immediately and the command will execute in the background MMBasic Language Manual Page 34 I2CDIS Disables the slave I C module and returns the external I O pins 12 and 13 to a not configured state Then can then be configured as per normal using SETPIN It will also send a stop if the bus is still held I2CSEND addr option Send data to the IC slave device sendlen senddata sendata addr is the slave i2c address feel option is a number between 0 and 3 1 keep control of the bus after the command a stop condition will not be sent at the completion of the command 2 treat the address as a 10 bit address 3 combine and 2 hold the bus and use 10 bit addresses sendlen is the number of bytes to send senddata is the data to be sent this can be specified in various ways all values sent will be between 0 and 255 e The data can be supplied in the command as individual bytes Example IZCSEND amp H6F 1 3 amp H23 amp H43 amp H25 e The data can be in a one dimensional array The subscript does not have to be zero and will be honoured also bounds checking is performed Example IZCSEND amp H6F 1 3 ARRAY 0 e The data can be a string variable not a constant Example I2CSEND amp H6F 1 3 STRING The automatic variable MM I2C will hold the result of the transaction I2CRCV addr bus_hold Receive data from the I
26. transparent background PRINT nbr expression MM Same as above except that the output is directed to a file previously L Jexpression etc DOS opened for OUTPUT or APPEND as nbr See the OPEN command PULSE pin width MM Will generate a pulse on pin with duration of width mS width can be a fraction For example 0 01 is equal to 10 uS This enables the generation of very narrow pulses The generated pulse is of the opposite polarity to the state of the I O pin when the command is executed For example if the output is set high the PULSE command will generate a negative going pulse Notes For a pulse of less than 1 mS the accuracy is 1 uS For a pulse of 1 mS or more the accuracy is 0 5 mS A pulse of more than 1 mS will run in the background pin must be configured as an output QUIT pos Will exit MMBasic and return control to the operating system RANDOMIZE nbr MM Seeds the random number generator with nbr To generate a different DOS random sequence each time you must use a different value for nbr One good way to do this is use the TIMER function For example 100 RANDOMIZE TIMER READ variable variable MM Reads values from DATA statements and assigns these values to the DOS named variables Variable types in a READ statement must match the data types in DATA statements as they are read See also DATA and RESTORE REM string MM REM allows remarks to be i
27. ARTICULAR PURPOSE The source code is available via subscription free of charge to individuals for personal use or under a negotiated license for commercial use In both cases go to http geoffg net maximite html for details This manual is distributed under a Creative Commons Attribution NonCommercial ShareAlike 3 0 Australia license CC BY NC SA 3 0 MMBasic Language Manual Page 8 Predefined Read Only Variables The centre column specifies the platform MM is Maximite family DOS is the Windows version MM HRES MM The horizontal resolution of the current video display screen in pixels MM VRES MM The vertical resolution of the current video display screen in pixels MM VER MM The version number of the firmware in the form aa bbcc where aa is the DOS major version number bb is the minor version number and cc is the revision number normally zero but A 01 B 02 etc MM DRIVE MM The current default drive returned as a string containing either A or B aR MM FNAME MM The name of the file that will be used as the default for the SAVE DOS command This is set by LOAD RUN and SAVE MM ERRNO MM Is set to the error number if a statement involving the SD card fails or zero DOS if the operation succeeds This is dependent on the setting of OPTION ERROR For the Maximite the possible values for MM ERRNO are No error No SD card found SD card is write protected Not enough spac
28. CEN I2CDIS I2CSEND and I2CRCV For slave mode the commands are I2CSEN I2CSDIS I2CSSEND and I2CSRCV The master and slave modes can be enabled simultaneously however once a master command is in progress the slave function will be idle until the master releases the bus Similarly if a slave command is in progress the master commands will be unavailable until the slave transaction completes Both the master and slave modes use an MMBasic interrupt to signal a change in status These interrupt routines operate the same as a general interrupt on an external I O pin see page 4 for a description and must be terminated with an IRETURN command to return control to the main program when completed The automatic variable MM I2C will hold the result of a command or action I2C Master Mode Commands I2CEN speed timeout Enables the C module in master mode int speed is a value between 10 and 400 for bus speeds 10 kHz to 400 kHz timeout is a value in milliseconds after which the master send and receive commands will be interrupted if they have not completed The minimum value is 100 A value of zero will disable the timeout though this is not recommended int is optional It specifies the line number or label of an interrupt routine to be run when the send or receive command completes If this is not supplied the send and receive command will only return when they have completed or timed out If it is supplied then
29. LSE ELSEIF expression THEN statement if false ea The ELSEIF statement if present is executed if the previous condition is false and it starts a new IF chain with further ELSE and or ELSEIF statements as required One ENDIF is used to terminate the multiline IF MMBasic Language Manual Page 15 INPUT prompt string MM Allows input from the keyboard to a list of variables The input command list of variables DOS will prompt with a question mark The input must contain commas to separate each data item if there is more than one variable For example if the command is INPUT a b c And the following is typed on the keyboard 23 87 66 Then a 23 and b 87 and c 66 If the prompt string is specified it will be printed before the question mark If the prompt string is terminated with a comma rather than the semicolon the question mark will be suppressed INPUT nbr MM Same as above except that the input is read from a file previously opened list of variables DOS for INPUT as nbr See the OPEN command IRETURN MM Returns from an interrupt The next statement to be executed will be the one that was about to be executed when the interrupt was detected KILL file MM Deletes the file specified by file DOS Quote marks are required around a string constant and the extension if there is one must be specified Example KILL SAMPLE DAT LET variable
30. MMBasic Language Manual Ver 3 2 Geoff Graham For updates to this manual and more details on MMBasic go to http mmbasic com or http geoffg net maximite html Copyright 2011 2012 Geoff Graham This manual is licensed under a Creative Commons Attribution NonCommercial ShareAlike 3 0 Australia CC BY NC SA 3 0 MMBasic is a Microsoft BASIC compatible implementation of the BASIC language with floating point and string variables long variable names arrays of floats or strings with multiple dimensions and powerful string handling MMBasic was originally written for the Maximite a small computer based on the PIC32 microcontroller from Microchip It now runs on a variety of hardware platforms including DOS This manual describes the MMBasic language For details of running MMBasic on specific platforms please refer to the following documentation Maximite and mini Maximite Maximite Hardware Manual from http geoffg net maximite html UBW32 experimenter board UBW32 MMBasic User Manual from http geoffg net ubw32 html CGMMSTICK1 board http www circuitgizmos com products cgmmstick1 cgmmstick1 shtml DuinoMite hardware DuinoMite MMBasic ReadMe included with the DuinoMite update DOS DOS MMBasic ReadMe from http mmbasic com downloads html Throughout this manual Maximite or MM refers to the Maximite family Maximite mini Maximite UBW32 CGMMSTICK1 DuinoMite and others that run the standard Maximite firm
31. al port ie using PRINT n data the command will pause if the output buffer is full and wait until there is sufficient space to place the new data in the buffer before returning If the receive buffer overflows with incoming data the serial port will automatically discard the oldest data to make room for the new data Serial ports can be closed with the CLOSE command This will discard any characters waiting in the buffers return the buffer memory to the memory pool and set all pins used by the port to the not configured state A serial port is also automatically closed when commands such as RUN and NEW are issued Interrupts The interrupt routine if specified will operate the same as a general interrupt on an external I O pin see page 4 for a description and must be terminated with an IRETURN command to return control to the main program when completed When using interrupts you need to be aware that it will take some time for MMBasic to respond to the interrupt and more characters could have arrived in the meantime especially at high baud rates So for example if you have specified the interrupt level as 200 characters and a buffer of 256 characters then quite easily the buffer will have overflowed by the time the interrupt routine can read the data In this case the buffer should be increased to 512 characters or more Opening a Serial Port as the Console A serial port can be opened as the console for MMBasic The command is OPEN c
32. am and if you used it in a program like this a amp b11101001 b RShift a 3 The variable b would have the binary value of 11101 The IF THEN command can span many lines with ELSEIF THEN ELSE and ENDIF statements as required and also spaced over many lines For example IF lt condition gt THEN start a multiline IF lt statements gt ELSEIF lt condition gt THEN the ELSEIF is optional lt statements gt ELSE the ELSE is optional lt statements gt ENDIF must be used to terminate the IF Compatibility MMBasic implements a large subset of Microsoft s GW BASIC There are numerous small differences due to physical and practical considerations but most MMBasic commands and functions are essentially the same An online manual for GW BASIC is available at http www antonis de qbebooks gwbasman index html and this provides a more detailed description of the commands and functions that are available MMBasic also implements a number of modern programming structures documented in the ANSI Standard for Full BASIC X3 113 1987 or ISO IEC 10279 1991 These include SUB END SUB the DO WHILE LOOP and structured IF THEN ELSE ENDIF statements MMBasic Language Manual Page 6 Implementation Details Naming Conventions Command names function names labels variable names file names etc are not case sensitive so that Run and RUN are equivalent and
33. and Program Input At the prompt the greater than symbol ie gt you can enter a command line followed by the enter key and it will be immediately run This is useful for testing commands and their effects Line numbers are optional If you use them you can enter a program at the command line by preceding each program line with a line number however it is recommended that the full screen editor the EDIT command be used to enter and edit programs When entering a line at the command prompt the line can be edited using the arrow keys to move along the line the Delete key to delete a character and the Insert key to switch between insert and overwrite The up arrow key will move through a list of previously entered commands which can be edited and reused A program held in memory can be listed with LIST run using the RUN command and cleared with the NEW command You can interrupt MMBasic at any time by typing CTRL C and control will be returned to the prompt Keyboard Display not DOS Input can come from either a keyboard or from a computer using a terminal emulator via the USB or serial interfaces Both the keyboard and the USB interface can be used simultaneously and can be detached or attached at any time without affecting a running program Output will be simultaneously sent to the USB interface and the video display VGA or composite Either can be attached or removed at any time Line Numbers Program Structure and Editing In version
34. and can then be used to reconfigure them The signal polarity is standard for devices running at TTL voltages not RS232 Idle is voltage high the start bit is voltage low data uses a high voltage for logic 1 and the stop bit is voltage high The flow control pins RTS and CTS use a low voltage to signal stop sending data and high as OK to send These signal levels allow you to directly connect to devices like the EM 408 GPS module which uses TTL voltage levels Reading and Writing Once a serial port has been opened you can use any commands or functions that use a file number to write and read from the port Generally the PRINT command is the best method for transmitting data and the INPUT function is the most convenient way of getting data that has been received When using the INPUT Q function the number of characters specified will be the maximum number of characters returned but it could be less if there are less characters in the receive buffer In fact the INPUT Q function will immediately return an empty string if there are no characters available in the receive buffer The LOC function is also handy it will return the number of characters waiting in the receive buffer ie the number characters that can be retrieved by the INPUT Q function The EOF function will return true if there are no characters waiting The LOF function will return the space in characters remaining in the transmit buffer When outputting to a seri
35. ard and you must change to the required directory before invoking it EOF nbr MM Will return true if the file previously opened for INPUT with the file DOS number nbr is positioned at the end of the file If used on a file number opened as a serial port this function will return true if there are no characters waiting in the receive buffer The is optional Also see the OPEN INPUT and LINE INPUT commands and the INPUT function EXP number MM Returns the exponential value of number DOS FIX number MM Truncate a number to a whole number by eliminating the decimal point DOS and all characters to the right of the decimal point For example 9 89 will return 9 and 2 11 will return 2 The major difference between FIX and INT is that FIX provides a true integer function ie does not return the next lower number for negative numbers as INT does This behaviour is for Microsoft compatibility See also CINTO FORMATS nbr fmt MM Will return a string representing nbr formatted according to the DOS specifications in the string fmt The format specification starts with a character and ends with a letter Anything outside of this construct is copied to the output as is The structure of a format specification is flags width precision type Where flags can be Left justify the value within a given field width 0 Use 0 for the pad character instead of space
36. ay data on the USB and video outputs This option is always reset to ON at the command prompt PAUSE delay MM Halt execution of the running program for delay mS DOS This can be a fraction For example 0 2 is equal to 200 uS The maximum delay is 4294967295 mS about 49 days PIN pin value MM Fora pin configured as digital output this will set the output to low value is zero or high value non zero You can set an output high or low before it is configured as an output and that setting will be the default output when the SETPIN command takes effect pin zero is a special case and will always control the LED on the front panel of the Maximite the yellow LED on the UBW32 or the green LED on the DuinoMite A value of non zero will turn the LED on or zero for off MMBasic Language Manual Page 19 See the function PIN for reading from a pin and the command SETPIN for configuring it PIXEL x y value MM Set a pixel on the VGA or composite screen off if value is zero or on if value is 1 or inverted if the value is 1 See page 5 for a definition of the graphics coordinates See the function PIXEL x y for obtaining the value of a pixel POKE hiword loword val MM DOS Will set a byte within the PIC32 virtual memory space to val hiword is the top 16 bits of the address while loword is the bottom 16 bits This command is for
37. baud is the baud rate either 19200 9600 4800 2400 1200 600 300 150 or 75 bits per second Default is 9600 e buf is the buffer sizes in bytes Two of these buffers will be allocated from the general memory area one for transmit and one for receive The default size is 256 bytes e int is the line number or label of an interrupt routine to be invoked when the serial port has received some data The default is no interrupt e intlevel is the number of characters that must be waiting in the receive queue before the receive interrupt routine is invoked The default is 1 character All parameters except the serial port name COMn are optional If any one parameter is left out then all the following parameters must also be left out and the defaults will be used Two options can be optionally added these are FC and OC They must be at the end of comspec and if both are specified must be in this order e FC will enable hardware flow control Flow control can only be specified on COMI and it enables two extra signals Request To Send receive flow control and Clear To Send transmit flow control Default is no flow control e OC will force the output pins Tx and optionally RTS to be open collector and can be used on both COM1 and COM2 The default is normal 0 to 3 3V output Examples Opening a serial port using all the defaults OPEN COM2 AS 2 Opening a serial port specifyin
38. bits set as 1 will always match option is a number between 0 and 3 1 allows MMBasic to respond to the general call address When this occurs the value of MM I2C will be set to 4 2 treat the address as a 10 bit address 3 combine 1 and 2 respond to the general call address and use 10 bit addresses send_int is the line number or label of a send interrupt routine to be invoked when the module has detected that the master is expecting data rcv_int is the line number or label of a receive interrupt routine to be invoked when the module has received data from the master I2CSDIS Disables the slave I C module and returns the external I O pins 12 and 13 to a not configured state Then can then be configured as per normal using SETPIN I2CSSEND sendlen Send the data to the C master This command should be used in the send senddata sendata interrupt ie in the send_int_line when the master has requested data Alternatively a flag can be set in the send interrupt routine and the command invoked from the main program loop when the flag is set sendlen is the number of bytes to send senddata is the data to be sent This can be specified in various ways see the IZCSEND commands for details I2CSRCYV revlen rcvbuf Receive data from the C master device This command should be used in rcvd the receive interrupt ie in the rcv_int_line when the master has sent some data Alter
39. character 0 and the frowning face in the position of number one 1 To display a smiley face your program would contain this 40 FONT LOAD FACES FNT AS 6 load the font 50 FONT 6 select the font 60 PRINT O print a smiley face example FACES FNT 11 11 48 49 XXX XX XX XX XX XX X X XX X X XX X X XX X XXX X XX XX XXX XXX XX XX XX XX XX XX XX XX XXX XX X X X X XX XX XXX MMBasic Language Manual Page 41 Appendix F Special Keyboard Keys Maximite family only MMBasic generates a single unique character for the function keys and other special keys on the keyboard These are shown in the table as hexadecimal and decimal numbers Keyboard Key Succ eisai Up Arrow 80 128 Down Arrow 81 129 Left Arrow 82 130 Right Arrow 83 I Insert 84 pa Home 86 T End 87 135 Page Up 88 BS Page Down 89 ea Alt 8B 139 Num Lock 8C 0 Fl 91 145 F2 92 146 F3 93 147 F4 94 148 F5 95 149 F6 96 150 F7 97 151 F8 98 152 F9 99 153 F10 9A 154 F11 9B 155 F12 9C 156 If the control key is simultaneously pressed then 20 hex is added to the code this is the equivalent of setting bit 5 If the shift key is simultaneously pressed then 40 hex is added to the code this is the equivalent of setting bit 6 If both are pressed 60 hex is added For example Control PageDown will generate A9 hex The shift modifier only w
40. ded using LOAD or merged with the current program using MERGE A saved program can also be loaded and run using the RUN command The RUN command can also be used within a running program which enables one program to load and transfer control to another Data files can be opened using OPEN and read from using INPUT LINE INPUT or INPUT or written to using PRINT or WRITE On the SD card both data and programs are stored using standard text and can be read and edited in Windows Apple Mac Linux etc An SD card can have up to 10 files open simultaneously while the internal flash drive has a maximum of one file open at a time You can list the programs stored on a drive with the FILES command delete them using KILL and rename them using NAME On an SD card the current working directory can be changed using CHDIR A new directory can be created with MKDIR or an old one deleted with RMDIR Whenever specified a file name can be a string constant ie enclosed in double quotes or a string variable This means you must use double quotes if you are directly specifying a file name Eg RUN TEST BAS External Input Output not DOS You can configure an external I O pin using the SETPIN command set its output using the PINQO command and read the current input value using the PIN Q function Digital I O uses the number zero to represent a low voltage and any non zero number for a high voltage An analogue input will report the measured voltage as a
41. e All root directory entries are taken Invalid filename Cannot find file Cannot find directory File is read only Cannot open file 0 Error reading from file 1 Error writing to file 12 Nota file 13 Not a directory 14 Directory not empty 15 Hardware error accessing the storage media 16 Flash memory write failure BrP OAANAMNARWNK CO MMBasic Language Manual Page 9 Commands The centre column specifies the platform MM is Maximite family DOS is the Windows version Square brackets indicate that the parameter or characters are optional single quotation mark MM Starts a comment and any text following it will be ignored Comments DOS can be placed anywhere on a line question mark MM Shortcut for the PRINT command DOS AUTO MM Enter automatic line entry mode To terminate this mode use Control C or DOS With no arguments this command will take lines of text from the AUTO start keyboard or USB and append them to program memory without ee modification This is useful for adding lines that do not have line AUTO numbers Sener If start is provided the lines will be prefixed with an automatically generated line number start is the starting line number and increment is the step size default 10 If the automatically generated number is the same as an existing line in memory it will be preceded by an asterisk In this case pressing Enter w
42. e Manual Page 16 LOAD file MM Loads a program called file from the current drive into program DOS memory Quote marks are required around a string constant Example LOAD TEST BAS If an extension is not specified BAS will be added to the file name LOCAL variable MM Defines a list of variable names as local to the subroutine or function variables DOS variable can be an array and the array will be dimensioned just as if the DIM command had been used A local variable will only be visible within the procedure and will be deleted and the memory reclaimed when the procedure returns If the local variable has the same name as a global variable used before any subroutines or functions were called the global variable will be hidden by the local variable while the procedure is executed LOOP UNTIL expression mm Terminates a program loop see DO DOS MEMORY MM List the amount of memory currently in use For example DOS 15kB 18 Program 528 lines 23kB 28 52 Variables 17kB 21 General 28kB 33 Free Program memory is cleared by the NEW command Variable and the general memory spaces are cleared by many commands eg NEW RUN LOAD etc as well as the specific commands CLEAR and ERASE General memory is used by fonts file I O buffers etc MERGE file MM Adds program lines from file to the program in memory Unlike DOS LOAD it does not clear the pro
43. e beginning of the program Or if a file name file is supplied the current program will be erased and that program will be loaded from the current drive and executed This enables one program to load and run another Example RUN TEST BAS If an extension is not specified BAS will be added to the file name SAVE file MM Saves the program in the current working directory as file The file DOS name is optional and if omitted the last filename used in SAVE LOAD or RUN will be automatically used Example SAVE TEST BAS If an extension is not specified BAS will be added to the file name SAVEBMP file MM Saves the current VGA or composite screen as a BMP file in the current working directory on the current drive Example SAVEBMP IMAGE BMP If an extension is not specified BMP will be added to the file name Note that Windows 7 Paint has trouble displaying the image This appears to be a bug in Paint as all other software tested including Windows XP Paint can display the image without fault SETPIN pin cfg MM Will configure the external I O pin according to cfg 0 Not configured or inactive 1 Analog input pins 1 to 10 2 Digital input all pins 5V tolerant on pins 11 and above 3 Frequency input pins 11 to 14 4 Period input pins 11 to 14 5 Counting input pins 11 to 14 6 Interrupt on low to high input change all pins 7 Interrupt on high to low input change all pins
44. e or more DOS characters waiting in the queue will remove the first character and return it as a single character in a string If the input buffer is empty this function will immediately return with an empty string ie INPUTS nbr fnbr MM Will return a string composed of nbr characters read from a file DOS previously opened for INPUT with the file number fnbr This function will read all characters including carriage return and new line without translation When reading from a serial communications port this will return as many characters as are waiting in the receive buffer up to nbr If there are no characters waiting it will immediately return with an empty string The is optional Also see the OPEN command INSTR start position MM Returns the position at which string pattern occurs in string searched string searched string DOS beginning at start position pattern INT number MM Truncate an expression to the next whole number less than or equal to the DOS argument For example 9 89 will return 9 and 2 11 will return 3 This behaviour is for Microsoft compatibility the FIXQ function provides a true integer function See also CINT LEFT string number MM Returns a substring of string with number of chars from the left of chars DOS beginning of the string LEN string MM Returns the number of characters in string DOS LOC nbr
45. ed they can be represented by either empty space between the commas or left off the end of the list Where e rx is the pin number for the data input MISO e tx is the pin number for the data output MOSI e clk is the pin number for the clock generated by MMBasic CLK e data_to_send is optional and is an integer representing the data byte to send over the output pin If it is not specified the tx pin will be held low e speed is optional and is the speed of the clock It is a single letter either H M or L where H is 3 MHz M is 500 KHz and L is 50 KHz Default is H e mode is optional and is a single numeric digit representing the transmission mode see Transmission Format below The default mode is 3 e bits is optional and represents the number of bits to send receive Range is 1 to 23 this limit is defined by how many bits can be stored in a floating point number The default is 8 The SPI function will return the data received during the transaction as an integer Note that a single SPI transaction will send data while simultaneously receiving data from the slave which is often discarded Examples Using all the defaults A SPI 11 12 13 Specifying the data to be sent A SPI 11 12 13 amp HE4 Setting the mode but using the defaults for data to send and speed A SPI 11 12 13 gt 2 An example specifying everything including a 12 bit data transfer A
46. ency inputs will return the frequency in Hz maximum 200 kHz A period input will return the period in milliseconds while a count input will return the count since reset counting is done on the positive rising edge The count input can be reset to zero by resetting the pin to counting input even if it is already so configured pin zero ie PIN 0 is a special case which will always return the state of the bootload or program push button on the PC board non zero means that the button is down Also see the SETPIN and PIN commands POS MM Returns the current cursor position in the line in characters DOS PIXEL x y MM Returns the value of a pixel on the VGA or composite screen Zero is off 1 is on See page 7 for a definition of the graphics coordinates See the statement PIXEL x y for setting the value of a pixel RAD degrees MM Converts degrees to radians DOS RIGHT string number MM Returns a substring of string with number of chars from the right of chars DOS end of the string RND number MM Returns a pseudo random number in the range of 0 to 0 99999 The DOS number value is ignored if supplied The RANDOMIZE command reseeds the random number generator SGN number MM Returns the sign of the argument number 1 for positive numbers 0 for DOS 0 and 1 for negative numbers MMBasic Language Manual Page 28 SIN
47. f in a subroutine DO WHILE expression MM Loops while expression is true this is equivalent to the older WHILE lt statements gt DOS WEND loop also implemented in MMBasic If at the start the LOOP expression is false the statements in the loop will not be executed even once DO MM Loops until the expression following UNTIL is true Because the test is lt statements gt DOS made at the end of the loop the statements inside the loop will be LOOP UNTIL expression executed at least once even if the expression is false DRIVE drivespec MM Change the default drive used for file operations that do not specify a drive to that specified in drivespec This can be the string A or B See also the predefined read only variable MM DRIVE EDIT MM Invoke the full screen editor This can be used to edit either the program or currently loaded in memory or a program file It can also be used to view EDIT filename and edit text data files or EDIT line number If EDIT is used on its own it will edit the program memory If filename is supplied the file will be edited leaving the program memory untouched On entry the cursor will be automatically positioned at the last line edited or if there was an error when running the program the line that caused the error If line number is specified on the command line the program in memory will be edited and cursor will be placed on the line specified The editing
48. g on the remote computer and connected to its serial port It has been tested on Tera Term running on Windows and it is recommended that this be used After running the XMODEM command in MMBasic select File gt Transfer gt XMODEM gt Receive Send from the Tera Term menu to start the transfer The transfer can take up to 15 seconds to start and if the XMODEM command fails to establish communications it will return to the MMBasic prompt after 60 seconds Download Tera Term from http ttssh2 sourceforge jp MMBasic Language Manual Page 24 Functions The centre column specifies the platform MM is Maximite family DOS is the Windows version Square brackets indicate that the parameter or characters are optional or DIR fspec or DIR _ ABS number MM Returns the absolute value of the argument number ie any negative DOS sign is removed and the positive number is returned ASC string MM Returns the ASCII code for the first letter in the argument string DOS ATN number MM Returns the arctangent value of the argument number in radians DOS BIN number MM Returns a string giving the binary base 2 value for the number DOS CHR number MM Returns a one character string consisting of the character corresponding DOS to the ASCII code indicated by argument number CINT number MM Round numbers with fractional portions up
49. g only the baud rate 4800 bits per second PEN COM2 4800 AS 1 O Ho ning a serial port specifying the baud rate 9600 bits per second and buffer size 1KB but no flow control N COM1 9600 1024 AS 8 same as above but with receive flow control RTS and transmit flow control CTS enabled PEN COM1 9600 1024 FC AS 8 So Ur Fl oO Or O gt oO An example specifying everything including an interrupt an interrupt level flow control and open collector OPEN COM1 19200 1024 ComIntLabel 256 FC OC AS 5 MMBasic Language Manual Page 32 Input Output Pin Allocation COM1 uses pin 15 for receive data data in and pin 16 for transmit data data out If flow control is specified pin 17 will be used for RTS receive flow control it is an output and pin 18 will be CTS transmit flow control it is an input COM2 uses pin 19 for receive data data in and pin 20 for transmit data data out These allocations apply to the Maximite UBW32 and exact Maximite clones The DuinoMite has a different set of allocations refer to the DuinoMite MMBasic ReadMe document for details When a serial port is opened the pins used by the port are automatically set to input or output as required and the SETPIN and PIN commands are disabled for the pins When the port is closed using the CLOSE command all pins used by the serial port will be set to a not configured state and the SETPIN comm
50. g will switch the video output on or off There is a CONFIG VIDEO OFF ON slight performance improvement with the video off but the biggest benefit is that the unused memory is returned to the general memory pool or used by strings and arrays Default is ON CONFIG CASE ae UPPER LOWER TITLE The CASE setting will change the case used for listing command and function names when using the LIST command The default is TITLE Or but the old standard of MMBasic can be restored using CONFIG CASE UPPER CONFIG KEYBOARD The KEYBOARD setting will change the keyboard layout to suit US FR I GR I BE I IT standard keyboards US French FR German GR Belgium BE or or Italian IT keyboards Default is US CONFIG TAB 21418 The TAB setting will set the spacing for the tab key Default is 2 The CONFIG command differs from other options It permanently reconfigures MMBasic and it only needs to be run once ie the setting will be remembered even with the power turned off The power must be cycled after changing a setting for it to take effect CONTINUE MM Resume running a program that has been stopped by an END statement DOS an error or CTRL C The program will restart with the next statement following the previous stopping point COPY src TO dest MM Copy the file named src to another file named dest dest can be DOS just a drive designation ie A and this makes it convenient to copy files between drives Note that it is not poss
51. gram currently in memory MKDIR dir MM Make or create the directory dir on the SD card DOS NAME old AS new MM Rename a file or a directory from old to new DOS Unlike the other commands that work with file names the NAME command cannot accept a full pathname with directories NEW MM Deletes the program in memory and clears all variables DOS NEXT counter variable MM NEXT comes at the end of a FOR NEXT loop see FOR counter variable etc DOS The counter variable specifies exactly which loop is being operated on If no counter variable is specified the NEXT will default to the innermost loop It is also possible to specify multiple counter variables as in NEXT x y z ON nbr GOTO GOSUB MM ON either branches GOTO or calls a subroutine GOSUB based on the target target target DOS rounded value of nbr if it is 1 the first target is called if 2 the second target is called etc Target can be a line number or a label MMBasic Language Manual Page 17 OPEN fname FOR mode AS fnbr MM DOS Opens a file for reading or writing fname is the filename 8 chars max with an optional extension 3 chars max separated by a dot It can be prefixed with a directory path For example B DIRI DIR2 FILE EXT mode is INPUT or OUTPUT or APPEND INPUT will open the file for reading and throw an error if the file does not exist OUTPUT wi
52. he editor will work with lines wider than the screen but characters beyond the screen edge will not be visible You can split such a line by inserting a new line character and the two lines can be later rejoined by deleting the inserted new line character All the editing keys work with a VT100 terminal emulator so editing can also be accomplished over a USB or serial link The editor has been tested with Tera Term and this is the recommended software Note that Tera Term must be configured for an 80 column by 36 line display Introduces a default condition in a multiline IF statement ELSE MM DOS See the multiline IF statement for more details ELSEIF expression THEN MM Introduces a secondary condition in a multiline IF statement DOS See the multiline IF statement for more details ENDIF MM Terminates a multiline IF statement DOS See the multiline IF statement for more details END MM End the running program and return to the command prompt DOS END FUNCTION MM Marks the end of a user defined function See the FUNCTION DOS command Each sub must have one and only one matching END FUNCTION statement Use EXIT FUNCTION if you need to return from a subroutine from within its body Only one space is allowed between END and FUNCTION END SUB MM Marks the end of a user defined subroutine See the SUB command DOS Each sub must have one and only one matching END SUB statement Use EXIT SUB if you need t
53. ible to have both the source and destination on the internal flash drive A COPYRIGHT MM List all contributors to the MMBasic and summarise the copyright DOS DATA constant constant MM Stores numerical and string constants to be accessed by READ pos String constants do not need to be quoted unless they contain significant spaces the comma or a keyword such as THEN WHILE etc Numerical constants can also be expressions such as 5 60 DATE DD MM YY MM Set the date of the internal clock calendar or DD MM and YY are numbers for example DATE 28 2 2011 DATE DD MM YY The date is set to 1 1 2000 on power up DELETE line MM Deletes a program line or a range of lines DELETE lastline DOS If lastline is used it will delete from the start of the first line in the DELETE firstline 3 l program to the end of lastline If startline is used it will delete from DELETE firstline lastline start of startline to the end of the program Also see the NEW command DIM variable elements MM Specifies variables that have more than one element in a single variable elements DOS dimension i e arrayed variables MMBasic Language Manual Page 11 DO MM This structure will loop forever the EXIT command can be used to lt statements gt DOS terminate the loop or control must be explicitly transferred outside of the LOOP loop by commands like GOTO or RETURN i
54. ith a variable number of arguments Any omitted arguments in the function s list will be set to zero or a null string Arguments in the caller s list that are a variable ie not an expression or constant will be passed by reference to the function This means that any changes to the corresponding argument in the function will also be copied to the caller s variable You must not jump into or out of a function using commands like GOTO GOSUB interrupts etc Doing so will have undefined side effects GOSUB target MM Initiates a subroutine call to the target which can be a line number or a DOS label The subroutine must end with RETURN GOTO target MM Branches program execution to the target which can be a line number or DOS a label IF expr THEN statement MM Evaluates the expression expr and performs the THEN statement if it is or DOS true or skips to the next line if false The optional ELSE statement is the IF expr THEN statement reverse of the THEN test This type of IF statement is all on one line ELSE statement The THEN statement construct can be also replaced with GOTO linenumber label IF expression THEN MM Multiline IF statement with optional ELSE and ELSEIF cases and ending lt statements gt DOS with ENDIF Each component is on a separate line ELSE Evaluates expression and performs the statement s following THEN if lt statements gt the expression is true or optionally the statement s following the E
55. ithout entering any text will preserve the line in memory and generate the next number CHDIR dir MM Change the current working directory on the SD card to dir DOS The special entry represents the parent of the current directory and represents the current directory CIRCLE x y r c LF MM Draws a circle on the video output centred at x and y with a radius of r If c is zero the pixels are turned off if it is 1 or not specified the pixels are turned on ie the circle is drawn and 1 will invert the pixels The F option will cause the circle to be filled according to the c parameter See page 5 for a definition of the graphics coordinates Note that because the pixels are not exactly square the circle will be oval to some degree CLEAR MM Delete all variables and recover the memory used by them DOS See ERASE for deleting specific array variables CLOSE nbr nbr MM Close the file s or serial port s previously opened with the file number DOS nbr The is optional Also see the OPEN command CLOSE CONSOLE MM Close a serial port that had been previously opened as the console CLS MM Clears the video display screen and places the cursor in the top left DOS corner MMBasic Language Manual Page 10 CONFIG COMPOSITE MM The COMPOSITE setting will change the timing for the composite video NTSC PAL output Default is PAL or The VIDEO settin
56. ll open the file for writing and will automatically overwrite any existing file with the same name APPEND will also open the file for writing but it will not overwrite an existing file instead any writes will be appended to the end of the file If there is no existing file the APPEND mode will act the same as the OUTPUT mode i e the file is created then opened for writing fnbr is the file number 1 to 10 The is optional Up to 10 files can be open simultaneously The INPUT LINE INPUT PRINT WRITE and CLOSE commands as well as the EOF and INPUT Q functions all use fnbr to identify the file being operated on See also OPTION ERROR and MM ERRNO for error handling OPEN comspec AS fnbr or OPEN comspec AS console MM Will open a serial port for reading and writing Two ports are available COM1 and COM2 and both can be open simultaneously For a full description with examples see Appendix A The DuinoMite is a little different refer to the DuinoMite MMBasic ReadMe document comspec is the serial port specification and has the form COMnhn baud buf int intlevel with an optional FC and or OC appended COMI uses pin 15 for receive data and pin 16 for transmit data and if flow control is specified pin 17 for RTS and pin 18 for CTS COM2 uses pin 19 for receive data and pin 20 for transmit data If the port is opened using fnbr the port can be written to and read from
57. lowed by a number A label is invalid in this construct New programs should use IF condition THEN GOTO linenbr label LOCATE x y MM Positions the cursor to a location in pixels and the next PRINT command will place its output at this location This construct is included for Microsoft compatibility New programs should use the PRINT x y construct see the PRINT command PRESET x y MM Turn off PRESET or on PSET a pixel on the video screen These statements are included for Microsoft compatibility New PSET x y programs should use the PIXEL x y statement SPC number MM This function returns a string of blank spaces number bytes long It is DOS similar to the SPACE function and is only included for Microsoft compatibility WHILE expression MM WHILE initiates a WHILE WEND loop DOS The loop ends with WEND and execution reiterates through the loop as WEND long as the expression is true This construct is included for Microsoft compatibility New programs should use the DO WHILE LOOP construct WRITE nbr expression MM Outputs the value of each expression separated by commas If expression DOS expression is a number it is outputted without preceding or trailing spaces If it is a string it is surrounded by double quotes The list is terminated with a new line If nbr is specified the output will be directed to a file previously opened for OUTPUT or APPEND as
58. natively a flag can be set in the receive interrupt routine and the command invoked from the main program loop when the flag is set revlen is the maximum number of bytes to receive rcvbuf is the variable to receive the data this is a one dimensional array or if revlen is 1 then this may be a normal variable The array subscript does not have to be zero and will be honoured also bounds checking is performed rcvd will contain actual number of bytes received by the command I2C Automatic Variable MM 12C Is set to indicate the result of an I2C operation 0 The command completed without error 1 Received a NACK response 2 Command timed out 4 Received a general call address when in slave mode MMBasic Language Manual Page 36 12C Utility Command NUM2BYTE number Convert number to four numbers containing the four separate bytes of array x number MMBasic numbers are stored as the C float type and are four bytes or in length NUM2BYTE number The bytes can be returned as four separate variables or as four elements of variable1l variable2 A SOTO E AMAER variable3 variable4 See the function BYTE2NUM for the reverse of this command 12C Utility Function BYTE2NUM array x Return the number created by storing the four arguments as consecutive or bytes MMBasic numbers are stored as the C float type and are four bytes in BYTE2NUM arg1 arg2
59. ncluded in a program DOS Note the Microsoft style use of the single quotation mark to denote remarks is also supported and is preferred RENUMBER MM Renumber the program currently held in memory including all references or DOS to line numbers in commands such as GOTO GOSUB ON etc RENUMBER first first is the first number to be used in the new sequence Default is 10 or incr is the increment for each line Default is 10 RENUMBER first incr or RENUMBER first incr start is the line number in the old program where renumbering should commence from The default is the first line of the program This command will first check for errors that may disrupt the renumbering process and it will only change the program in memory if no errors are found However it is prudent to save the program before running this command in case there are some errors that are not caught MMBasic Language Manual Page 21 RESTORE MM Resets the line and position counters for DATA and READ statements to DOS the top of the program file RETURN MM RETURN concludes a subroutine called by GOSUB and returns to the DOS statement after the GOSUB RMDIR dir MM Remove or delete the directory dir on the SD card DOS RUN line file MM Executes the program in memory If a line number is supplied then DOS execution will begin at that line otherwise it will start at th
60. o return from a subroutine from within its body Only one space is allowed between END and SUB ERASE variable MM Deletes arrayed variables and frees up the memory variable DOS Use CLEAR to delete all variables including all arrayed variables ERROR error_msg MM Forces an error and terminates the program This is normally used in DOS debugging or to trap events that should not occur EXIT MM EXIT by itself provides an early exit from a DO LOOP EXIT FOR DOS EXIT FOR provides an early exit from a FOR NEXT loop EXIT FUNCTION EXIT FUNCTION provides an early exit from a defined function EXIT SUB EXIT SUB provides an early exit from a defined subroutine Only one space is allowed between the two words MMBasic Language Manual Page 13 FILES fspec MM DOS Lists files in the current directory on the SD or internal drive drive A The SD card drive B may use an optional fspec Question marks will match any character and an asterisk will match any number of characters If omitted all files will be listed For example is Find all entries TXT Find all entries with an extension of TXT E Find all entries starting with E X X Find all three letter file names starting and ending with X FONT nbr or FONT nbr scale or FONT nbr scale reverse MM Selects a font for the video output nbr is the font number in the range of 1 to 10 The symbol is opti
61. omspec AS CONSOLE In this case any characters received from the serial port will be treated the same as keystrokes received from the keyboard and any characters sent to the video output will also be transmitted via the serial port This enables a user with a terminal at the end of the serial link to exercise remote control of MMBasic For example via a modem Note that only one serial port can be opened AS CONSOLE at a time and it will remain open until explicitly closed using the CLOSE CONSOLE command It will not be closed by commands such as NEW and RUN MMBasic Language Manual Page 33 Appendix B l2C Communications Maximite family only The Inter Integrated Circuit IC bus was developed by the electronics giant Philips for the transfer of data between integrated circuits It has been adopted by many manufacturers and can be used to communicate with many devices including memories clocks displays speech module etc Using the I C bus is complicated and if you do not need to communicate with these devices you can safely ignore this section This implementation was developed by Gerard Sexton and fully supports master and slave operation 10 bit addressing address masking and general call as well as bus arbitration ie bus collisions in a multi master environment In the master mode there is a choice of 2 modes interrupt and normal In normal mode the I2C send and receive commands will not return until the command com
62. onal scale is the multiply factor in the range of 1 to 8 eg a scale of 2 will double the size of a pixel in both the vertical and horizontal Default is 1 If reverse is a number other than zero the font will be displayed in reverse video Default is no reverse There are three fonts built into MMBasic 1 isthe standard font of 10 x 5 pixels containing the full ASCH set 2 isa larger font of 16 x 11 pixels also with the full ASCII set 3 is ajumbo font of 30 x 22 pixels consisting of the numbers zero to nine and the characters plus minus space comma and full stop Examples 10 FONT 3 2 1 double scale and reverse video 10 FONT 3 0 reset to normal video 10 FONT 2 just select font 2 Font 1 with a scale of one and no reverse is the default on power up and will be reinstated whenever control returns to the input prompt Other fonts can be loaded into memory see the FONT LOAD command FONT LOAD file AS nbr MM Loads the font contained in file and install it as font nbr which can be any number between 3 and 10 The symbol is optional Appendix E describes the format of the font file The font is loaded into the general memory area used by arrays and strings Use the MEMORY command to check the usage of this area FONT UNLOAD nbr MM Removes font nbr and frees the memory used The symbol is optional You cannot unload the built in fonts FOR counter start TO finish
63. or down to the next whole DOS number or integer For example 45 47 will round to 45 45 57 will round to 46 34 45 will round to 34 34 55 will round to 35 See also INTO and FIXO COS number MM Returns the cosine of the argument number in radians DOS CWD MM Returns the current working directory as a string DOS DATE MM Returns the current date based on MMBasic s internal clock as a string in DOS the form DD MM YYYY For example 28 02 2011 The internal clock calendar will keep track of the time and date including leap years The date is set to 1 1 2000 on power up To set the date use the command DATE DEG radians MM Converts radians to degrees DOS DIR amp fspec type MM Will search an SD card for files and return the names of entries found fspec is a file specification using wildcards the same as used by the FILES command Eg will return all entries TXT will return text files type is the type of entry to return and can be one of VOL Search for the volume label only DIR Search for directories only FILE Search for files only the default if type is not specified MMBasic Language Manual Page 25 The function will return the first entry found To retrieve subsequent entries use the function with no arguments ie DIR The return of an empty string indicates that there are no more entries to retrieve This function only operates on the SD c
64. orks with the function keys F1 to F12 it is ignored for the other keys MMBasic will translate most VT100 escape codes generated by terminal emulators such as Tera Term and Putty to these codes excluding the shift and control modifiers This means that a terminal emulator operating over a USB or a serial port opened as console will generate the same key codes as a directly attached keyboard This is particularly useful when using the EDIT command MMBasic Language Manual Page 42 Appendix G Tera Term Setup Maximite family only MMBasic creates a virtual serial port over USB so that you can communicate with it from a Windows Linux or Macintosh computer using nothing more than the USB port The communications protocol used is the CDC Communication Device Class protocol and there is native support for this in Linux the cdc acm driver and Apple OS X Macintosh users can refer to the document Using Serial Over USB on the Macintosh on http geoffg net maximite html The rest of this tutorial assumes that you are using a computer running Windows XP Vista or 7 First you need to install the Windows Serial Port Driver available from http geoffg net maximite html Full instructions are included in the download and when you have finished you should see the connection in Device Manager as a numbered communications port ie COM13 To communicate with MMBasic over this virtual serial port you need to use a terminal emulator This is a
65. pletes or a timeout occurs if the timeout option has been specified In interrupt mode the send and receive commands return immediately allowing other MMBasic commands to be executed while the send and receive are in progress When the send receive transactions have completed an MMBasic interrupt will be executed This allows you to set a flag or perform some other processing when this occurs When enabled the I C function will take control of the external I O pins 12 and 13 and override SETPIN and PINQ commands for these pins Pin 12 becomes the PC data line SDA and pin 13 the clock SCL Both of these pins should have external pullup resistors installed typical values are 10KQ for 100KHz or 2KQ for 400 kHz Refer to the diagrams at the start of this manual for the location of pins 12 and 13 on the external I O connector Be aware that when running the I C bus at above 150 kHz the cabling between the devices becomes important Ideally the cables should be as short as possible to reduce capacitance and also the data and clock lines should not run next to each other but have a ground wire between them to reduce crosstalk If the data line is not stable when the clock is high or the clock line is jittery the I C peripherals can get confused and end up locking the bus normally by holding the clock line low If you do not need the higher speeds then operating at 100 kHz is the safest choice There are four commands for master mode IZ
66. protocols and the PIN command will continue to operate as normal on them Also because the I O pins can be changed between function calls it is possible to communicate with many different SPI slaves on different I O pins Example The following example will send the command amp H80 and receive two bytes from the slave SPI device Because the mode speed and number of bits are not specified the defaults are used SETPIN 18 2 set rx pin as a digital input SETPIN 19 8 set tx pin as an output PIN 20 1 SETPIN 20 8 set clk pin high then set it as an output PIN 11 1 SETPIN 11 8 pin 11 will be used as the enable signal PIN 11 0 assert th nable line active low junk SPI 18 19 20 amp H80 send the command and ignore the return bytel SPI 18 19 20 get the first byte from the slave byte2 SPI 18 19 20 get the second byte from the slave PIN 11 1 deselect the slav MMBasic Language Manual Page 40 Appendix E Loadable Fonts Maximite family only This section describes the format of a font file that can be loaded using the FONT LOAD command A font file is just a text file containing ordinary characters which are loaded line by line to build the bitmap of each character in the font Each character can be up to 64 pixels high and 255 pixels wide Up to 255 characters can be defined The first non comment line in the file must be the specifications for the fon
67. same as adding a new command to MMBasic while it is running your program xxx is the subroutine name and it must meet the specifications for naming a variable arg1l arg2 etc are the arguments or parameters to the subroutine Every definition must have one END SUB statement When this is reached the program will return to the next statement after the call to the subroutine The command EXIT SUB can be used for an early exit You use the subroutine by using its name and arguments in a program just as you would a normal command For example MySub al a2 When the subroutine is called each argument in the caller is matched to the argument in the subroutine definition These arguments are available only inside the subroutine Subroutines can be called with a variable number of arguments Any omitted arguments in the subroutine s list will be set to zero or a null string Arguments in the caller s list that are a variable ie not an expression or constant will be passed by reference to the subroutine This means that MMBasic Language Manual Page 23 any changes to the corresponding argument in the subroutine will also be copied to the caller s variable and therefore may be accessed after the subroutine has ended Brackets around the argument list in both the caller and the definition are optional SYSTEM command DOS Submit command to the operating system It can be any command recognised b
68. t as follows height width start end Where height and width are the size of each character in pixels start is the number in the ASCII chart where the first character sits and end is the last character Each number is separated by a comma So for example 16 11 48 57 means that the font is 16 pixels high and 11 wide The first character is decimal 48 the zero character and the last is 57 number nine character The remainder of the lines specify the bitmap for each character Each line represents a horizontal row of pixels A space means the pixel is not illuminated and any other character will turn the pixel on If the font is 11 pixels wide there must be 11 characters in the line although trailing spaces can be omitted The first line is the top row of pixels in the character the next is the second and so on If the character is 16 pixels high there must be 16 lines to define the character This repeats until each character is drawn Using the above example of a font 16x11 with 10 characters there must be a total of 160 lines with each line 11 characters wide This is in addition to the specification line at the top A comment line has an apostrophe as the first character and can occur anywhere A comment line is completely ignored all other lines are significant The following example creates two small icons a smiley face and a frowning face Each is 11x11 pixels with the first the smiley face in the position of the zero
69. till accepting interrupts you should use the INKEY function When using interrupts the main program is completely unaffected by the interrupt activity unless a variable used by the main program is changed during the interrupt For most programs MMBasic will respond to an interrupt in under 100uS To prevent slowing the main program by too much an interrupt should be short and execute the IRETURN statement as soon as possible Also remember to disable an interrupt when you have finished needing it background interrupts can cause strange and non intuitive bugs Graphics not DOS Graphics commands operate on the video output Coordinates are measured in pixels with x being the horizontal coordinate and y the vertical coordinate The top left of the screen is at location x 0 and y 0 and the bottom right of the screen defined by the read only variables x MM HRES and y MM VRES which change depending on the video mode selected VGA or composite Increasing positive numbers represent movement down the screen and to the right You can clear the screen with CLS and an individual pixel can be turned on or off with PIXEL x y You can draw lines and boxes with LINE and circles using CIRCLE You can also set the screen location in pixels of the next PRINT output using LOCATE and the SAVEBMP command will save the current screen as a BMP file The colour parameter for these commands can be zero to turn a pixel off 1 to turn the pixel on or 1
70. to invert a pixel This last function is useful in animation Sound not DOS The SOUND command will generate a simple square wave between 20Hz and 1MHz lasting for a specified duration This command can also be used to generate a Pulse Width Modulation PWM signal Expressions In most cases where a number or string is required you can also use an expression For example FNAME TEST RUN FNAME BAS Structured Statements MMBasic supports a number of modern structured statements The DO WHILE LOOP command and its variants make it easy to build loops without using the GOTO statement SUB and END sub make it easy to add your own commands to MMBasic For example SUB REVERSE strS LOCAL x FOR x LEN str TO 0 STEP 1 PRINT MIDS str x 1 NEXT x END SUB You have now added the new command REVERSE to your program and if you used it in a program like this REVERSE Hello World It would print the following on the screen dlroW olleH MMBasic Language Manual Page 5 Similarly the FUNCTION and END FUNCTION commands make it easy to add your own functions to MMBasic For example if you needed a function to right shift a number by an arbitrary number of bits you could write FUNCTION RShift nbr bits If nbr lt 0 or bits lt 0 THEN ERROR Invalid argument RShift nbr 2 bits END FUNCTION You have now added the function RShift to your progr
71. urn the next device 16 verify that the device with the serial number in ser is available If srchflag 0 or 2 then the search will return the next device found ser serial number 8 bytes will be returned srchflag 4 and 16 will also use the values in ser After the command is executed the pin will be set to the not configured state unless flag option 8 is used The data and ser arguments can be a string array or a list of variables The OWRESET and OWSEARCH commands and the OWREAD and OWWRITE commands if a reset is requested set the MM OW variable to 1 OK presence detected search successful or 0 Fail presence not detected search unsuccessful There are two utility functions available OWCRC8 len cdata cdata Processes the cdata and returns the 8 bit CRC OWCRC16 len cdata cdata Processes the cdata and returns the 16 bit CRC Where len length of data to process cdata data to process The cdata can be a string array or a list of variables MMBasic Language Manual Page 38 Appendix D SPI Communications Maximite family only The Serial Peripheral Interface SPI communications protocol is used to send and receive data between integrated circuits The SPI function in MMBasic acts as the master ie MMBasic generates the clock The syntax of the function is received_data SPI rx tx clk data_to_send speed mode bits Data_to_send speed mode and bits are all optional If not requir
72. using any commands or functions that use a file number A serial port can be opened with AS CONSOLE In this case any data received will be treated the same as keystrokes received from the keyboard and any characters sent to the video output will also be transmitted via the serial port This enables remote control of MMBasic via a Serial interface OPTION BASE 0 or OPTION BASE 1 MM DOS Set the lowest value for array subscripts to either O or 1 The default is 0 This must be used before any arrays are declared OPTION ERROR CONTINUE or OPTION ERROR ABORT MM DOS Set the treatment for errors in file input output The option CONTINUE will cause MMBasic to ignore file related errors The program must check the variable MM ERRNO to determine if and what error has occurred The option ABORT sets the normal behaviour ie stop the program and print an error message The default is ABORT Note that this option only relates to errors reading from or writing to drives A and B It does not affect the handling of syntax and other program errors MMBasic Language Manual Page 18 OPTION PROMPT string MM Sets the command prompt to the contents of string which can also be DOS an expression which will be evaluated when the prompt is printed For example OPTION PROMPT Ok or OPTION PROMPT TIMES or OPTION PROMPT CWD Maximum length of the prompt string
73. ware DOS refers to the version that runs in a DOS box under Windows Contents F nctional INA Yc eee che adele cdc eee ae een enacts 3 Implementation Details iecccesccsdessves2ueccusetedecesatusasnsudatecweetetesussietacsseivixevsucuds cnsedateneeatutecgecdetecets 7 Predefined Read Only Variables cccccceceecssescecceeeeeeeeeeeeeeeaeeeeeeeeeeeeeaeaaaaaaeeeeeeseeeeneenaaaees 9 COMMANA atc gt iaiaaeaia ase 10 C06 110 9 gt teen nee Perna ee ear nr en eet E EAEE EE ere EEEE 25 Obsolete Commands and Functions sasiucectceetieei cca ctsetaeeaeenneiecsmeiesenaiueadameeeesals 31 Appendix A Serial Communications cceeeeeeeeeeeeeeececeeeeeeeeeeeeeeeeceeaaeeeeeeeeeeeeeeeeenieeeeeeees 32 Appendix B I2C Communications xcceteccnexaranscenate detente eapcadecateretecssenstacdtanttes mapaetaaatenttecaerdiets 34 Appendix C 1 Wire COmmumniCallOns sccciceticccceterncaceteceeit catetitebieupinebisatul tees ieeatenicetoucieenaae 38 Appendix D SPI COMMUMICATIONS iicasccesciasiesnrsacuconmenentuenessudaanseeudseveeevs seus aendnsveseetenmasudamneeemeens 39 Appendix E Loadable gr 9 Come eeeemree nner enna meme re na re ern reer nr ena ee ee 41 Appendix F Special Keyboard KeYS ccccceeeeeeeeeeeeeeeeeeeeeeeeeeeeeaaaaeeeeeeeseeeeseceaeaeeeeeees 42 Appendix G Tera Term Setup ccccccccccccceececcsccceeceeeeeeeeeeaaeaeeeeeeeeeeeaaaaaeeeeeeeeeeeeeseseneeaaeeeeeees 43 MMBasic Language Manual Page 2 Functional Summary Command
74. without a decimal point while fractions are printed with the decimal point and the significant decimal digits Large numbers greater than six digits are printed in scientific format The function FORMATS can be used to format numbers The function TABQ can be used to space to a certain column and the string functions can be used to justify or otherwise format strings A single question mark can be used as a shortcut for the PRINT keyword PRINT x y expression Or PRINT x y m expression MM Same as the PRINT command except that the cursor is positioned at the coordinates x y Example PRINT 150 45 Hello World The function can be used anywhere in a print command Example PRINT 150 45 Hello 150 55 World The x y function can be used to position the cursor anywhere on or off the screen For example PRINT 10 0 Hello will only show Ilo as the first two characters could not be shown because they were off MMBasic Language Manual Page 20 the screen The x y function will automatically suppress the automatic line wrap normally performed when the cursor goes beyond the right screen margin If m is specified the mode of the video operation will be as follows m 0 Normal text white letters black background m 1 The background will not be drawn ie transparent m 2 The video will be inverted black letters white background m 5 Current pixels will be inverted
75. y the command window in Windows XP Vista 7 The available commands are listed here http ss64 com nt For example this will set the window to blue lettering on a yellow background SYSTEM COLOR 1E Note that the command is executed in a different instance of the command processor to MMBasic so some commands like CD will have no effect TIME HH MM SS MM Sets the time of the internal clock MM and SS are optional and will or default to zero if not specified For example TIME 14 30 will set TIMES HH MM the clock to 14 30 with zero seconds a The time is set to 00 00 00 on power up TIME HH TIMER msec MM Resets the timer to a number of milliseconds Normally this is just used DOS to reset the timer to zero but you can set it to any positive integer See the TIMER function for more details TROFF MM Turns the trace facility off see TRON DOS TRON MM Turns on the trace facility This facility will print each line number in DOS square brackets as the program is executed This is useful in debugging programs XMODEM SEND file MM Transfers a file to or from a remote computer using the XModem or protocol The transfer is done over the USB connection or if a serial port XMODEM RECEIVE file is opened as console over that serial port file is the file on the SD card or internal flash to be sent or received The XModem protocol requires a cooperating software program runnin

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