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FM Audio Link Authors: Project Sponsor: Service Manual

1. Check frequency to ensure it is not already at min value frequ2 Freq frequ2 Freq2 frequ2 Freq3 frequ2 Freq4 frequ2 Freq5 frequ2 Freq6 frequ2 Freq7 frequ2 500000000 value wrap back around to min value freq trans Transmit new frequency freq trans Transmit new frequency Service Manual Page 44 of 63 Home Radio stoff ston btfss goto movlw movwf movlw btfss goto ifndef else endif btfss goto bcf goto bsf goto SterB 1 0x00C Dlay 0 007 SterB 6 Debug btfsc decfsz goto decfsz goto SterL ston SterL txst SterL txst 1 STATUS Z Dlay 5 Dlay 3 mutoff muton Version 1 btfss goto movlw movwf movlw btfss goto ifndef else endif btfss goto bcf goto bsf goto MuteB 1 0x00C Dlay 0 007 MuteB 6 Debug addlw btfsc decfsz goto decfsz goto MuteL muton MuteL txmut MuteL txmut 1 STATUS 2 Dlay 5 Dlay 3 ls the stereo mono button still pressed Yes go back for debounce Delay 20 msecs Is the stereo mono button still pressed Yes go back again Skip small loop if Debug is defined Increment the delay count low byte in w is not equal to zero then loop Else short loop 15 stereo already selected No change from mono to stereo Yes turn stereo LED off Turn stereo LED on the stereo mono butt
2. Decimals Version 1 Service Manual Page 38 of 63 Home Radio December 14 2001 All of the four seven segment display resistor 7447 BCD Decoder displays are exactly the same with one exception pin 9 on the ones display should be tied to ground through a 330 resistor to activate the decimal point 7447 5 5 N 330 9 Figure 4 BCD Decoder to Seven Segment Display Connections Version 1 Service Manual Page 39 of 63 Home Radio December 14 2001 3c PIC Subsystem Code This code should be compiled using Microchip s MPLAB software It can be downloaded at Microchip s website http www microchip com The generated hex file can be burned to the PIC using the PICStartPlus software attached to MPLAB or with the EPIC PIC programming software http www melabs com products epic htm PIC Subsystem Processor Decs LIST p 16f877 include cAProgra 1MPLAB p16f877 INC Register Usage CBLOCK 0x00C Start registers at end of the values Dlay High byte of delay variable ENDC freq equ 0x020 Holds frequency value count equ 0x021 Holds counter for delay oldfrq equ 0x022 Holds previous frequency value addr equ 0x030 Holds eeprom data address not currently used define freq define Freq1 freq define Freq2 freq define Freq3 freq define Freq4 freq define 5 freq define freq define
3. Male SMA to Male BNC Adapter Quantity Value Type 2 3 3K 2 10K 1 33 K Resistor 1 2 2K 2 82 1 360 3 2200pF 2 150pF 2 1000pF 2 100uF 1 82 Capacitor 2 33pF 1 0 01uF 3 10uF 5 luF 2 22pF ne Potentiometer 1 BH1415F ROHM Stereo Modulation IC 1 FEMIOC 3F6 SUMIDA Variable Inductor 1 KV1714E TOKO Varactor Diode 1 2SC2062S ROHM Darlington Transistor 1 GFWB6 SOSHIN Band Pass Filter 1 7 6 MHz Crystal Oscillator 2 RCA Jack 1 BNC Whip Antenna 1 RF2334 RF MICRO DEVICES RF Amplifier 1 Male SMA Connector 1 1 Printed Circuit Board Version 1 Service Manual December 14 2001 Page 57 of 63 Home Radio Onboard Display and Communication Components Quantity Value Type 1 Perf Board 1 PIC16F877 MICROCHIP Microprocessor 4 330 Resistor Pack 7 4 7447 BCD Decoder 4 7 Segment Display 1 MAX232 MAXIM RS232 Voltage Converter 1 40 pin socket 2 20 pin socket 8 14 pin socket 7 16 pin socket 1 8 pin socket 1 Project Box 2 Red LED 2 Green LED 1 Power Jack 1 AC Adapter 1 Cigarette Lighter Adapter 4 Pushbuttons 1 20 MHz Crystal Oscillator 2 22pF rie Capacitor 1 47uF 4 330 Resistor 1 7805 Voltage Regulator 1 Diode 1 Serial Cable 1 Female DB9 serial connector Version 1 Service Manual December 14 2001 Page 58 of 63
4. Home Radio December 14 2001 Audio Selection Interface The Audio Selection Interface is used to open up a single audio device i e CD ROM Once the user selects to play one of the three supported file types the interface is closed giving control to the Audio Player Interface This is done using the following functions List Click stores the user s choice of audio source closes the Audio Selection Interface and give control to the Audio Player Interface Version 1 Service Manual Page 10 of 63 Home Radio December 14 2001 2b PIC Subsystem The 330 W resistor packs 7447 BCD decoders and PIC microcontroller are all placed into sockets The various capacitors resistors the oscillator and the voltage regulator are also placed in sockets for easy replacement There are only a few items not placed in sockets the diode needed for the voltage regulator circuit is soldered directly to the 12 volt input and the 330 resistors needed for the power indicator stereo and mute LED s are soldered directly to the jumpers for those respective lights All socket pin connections are made with wire wrap except for the PIC s socket which is soldered 7447 PIC 16F877 UJ c o GND Bus 2 Figure 3 PIC System Board Top Version 1 Service Manual Page 11 of 63 Home Radio December 14 2001 Ground Bus 1 This socket creates a bus by simply connecting the pins on the left side to those on the right with
5. Register Page 1 Disable transmission Register Page 0 Register page 2 Write address to read from Register page 3 Point to data memory Service Manual December 14 2001 Page 47 of 63 Home Radio bsf bcf movf movwf bcf bcf return DataWrite EECON1 RD STATUS RPO EEDATA w freq STATUS 5 STATUS 6 This feature is not currently in use wdata bsf bsf btfsc goto bcf movf movwf movf movwf bsf bcf bsf movlw movwf movlw movwf bsf bcf bcf bcf return org decone addwf retlw retlw retlw retlw retlw retlw retlw retlw retlw Version 1 STATUS STATUS RPO EECON1 WR 1 STATUS RPO addr w EEADR freq w EEDATA STATUS RPO EECON1 EEPGD EECON1 WREN 0x55 EECON2 OxAA EECON2 EECON1 WR EECON1 WREN STATUS 5 STATUS 6 0x300 PCL F b 01111001 b 10000000 b 10000001 b 10000010 b 1000001 1 b 10000100 b 10000101 b 10000110 b 10000111 b 10001000 Start read operation Register page 2 Read in data Store frequency data Register page 0 Return to previous position in code Register page 3 Wait for write to finish Register page 2 Address to write to Load frequency data to write Register page 3 Point to data memory Enable writes Write 55h to EECON2 Write AAh to EECON2 Start write operation Disable writes Register page
6. 4 Decimals 1 Ones 4 Decimals 2 Ones 4 Decimals 3 Ones 4 Decimals 4 Ones 4 Decimals 5 Ones 4 Decimals 6 Ones 4 Decimals 7 Ones 4 Decimals 8 Ones 4 Decimals 9 Ones 5 Decimals 0 Ones 5 Decimals 1 Ones 5 Decimals 2 Ones 5 Decimals 3 Ones 5 Decimals 4 Ones 5 Decimals 5 Ones 5 Decimals 6 Ones 5 Decimals 7 Ones 5 Decimals 8 Service Manual December 14 2001 Page 49 of 63 Home Radio Version 1 retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw b 01011001 b 01100000 b 01100001 b 01100010 b 01100011 b 01100100 b 01100101 b 01100110 b 01100111 b 01101000 b 01101001 b 01110000 b 01110001 b 01110010 b 01110011 b 01110100 b 01110101 b 01110110 b 01110111 b 01111000 b 01111001 b 10000000 b 10000001 b 10000010 b 10000011 b 10000100 b 10000101 510000110 510000111 510001000 510001001 510010000 510010001 510010010 510010011 510010100 510010101 510010110
7. 500000011 500000011 500000011 500000011 500000011 500000011 500000011 500000011 500000011 500000011 500000011 500000011 500000011 500000011 500000011 500000011 500000011 500000011 500000011 500000011 500000100 500000100 500000100 500000100 500000100 500000100 500000100 500000100 500000100 500000100 500000100 500000100 500000100 500000100 500000100 500000100 500000100 500000100 500000100 500000100 500000100 500000100 500000100 500000100 500000100 500000100 500000100 500000100 500000100 Hundreds 0 Tens 9 Hundreds 0 Tens 9 Hundreds 0 Tens 9 Hundreds 0 Tens 9 Hundreds 0 Tens 9 Hundreds 0 Tens 9 Hundreds 0 Tens 9 Hundreds 0 Tens 9 Hundreds 0 Tens 9 Hundreds 0 Tens 9 Hundreds 0 Tens 9 Hundreds 0 Tens 9 Hundreds 0 Tens 9 Hundreds 0 Tens 9 Hundreds 0 Tens 9 Hundreds 0 Tens 9 Hundreds 0 Tens 9 Hundreds 0 Tens 9 Hundreds 0 Tens 9 Hundreds 0 Tens 9 Hundreds 0 Tens 9 Hundreds 0 Tens 9 Hundreds 0 Tens 9 Hundreds 0 Tens 9 Hundreds 0 Tens 9 Hundreds 0 Tens 9 Hundreds 0 Tens 9 Hundreds 0 Tens 9 Hundreds 0 Tens 9 Hundreds 0 Tens 9 Hundreds 0 Tens 9 Hundreds 0 Tens 9 Hundreds 0 Tens 9 Hundreds 0 Tens 9 Hundreds 0 Tens 9 Hundreds 0 Tens 9 Hundred
8. December 14 2001 This section contains code for both the audio player and the PC s transmitter control It should be compiled with Microsoft Visual Basic 6 0 which can be found in the Microsoft Visual Studio software package About Form Code Private Sub cmdOK_Click Unload AboutForm End Sub Audio Player Form Code Private Sub Form Load Initialize Device Type Error Chex DeviceType 1 Initialize Clock Variables AudioPlayer Counter 0 AudioPlayer Clock_Tens 0 AudioPlayer Clock_Minutes 0 AudioPlayer Clock_Hours 0 AudioSelection Show 1 Use MMControl for CD Audio MMControl1 Notify False MMControl1 Wait True MMControl1 Shareable False MMControl1 DeviceType CDAudio MMControl1 Command Open End Sub Private Sub Mode Click AudioSelection Show 1 End Sub Private Sub Next Click Hours Picture LoadPicture AA0 bmp Minutes Picture LoadPicture A 0 omp Tens Picture LoadPicture A 0 bmp Ones Picture LoadPicture A 0 bmp AudioPlayer Counter 0 AudioPlayer Clock_Tens 0 AudioPlayer Clock_Minutes 0 AudioPlayer Clock_Hours 0 sure device has been selected If DeviceType 1 Then AudioSelection Show 1 End If Select Correct Device If AudioPlayer DeviceType 0 Then Do Nothing Version 1 Service Manual Page 23 of 63 Home Radio Else MMControl1 Command Next End If End Sub Private Sub Open_Click Select C
9. Page 41 of 63 Home Radio movwf btfss goto movfw movwf tstf goto chkdn btfss goto chkup X btfss goto chkst btfss goto chkmu btfss goto goto Check Input chkin btfss goto btfss goto btfss goto btfss goto btfsc goto btfsc goto goto tscom bsf bsf bcf movlw movwf bsf tscom2 btfss goto bcf call bsf bcf bcf Version 1 oldfrq PIR1 5 chkdn RCREG freq freq chkin DownB fregd UpB frequ SterB togst MuteB togmu main Freq7 dispf Freq6 dispf Freq5 dispf Freq4 dispf Freq2 tscom Freq pcmute pester STATUS 5 TXSTA 5 STATUS 5 OxF4 TXREG STATUS 5 TXSTA 1 tscom2 STATUS 5 delay STATUS 5 TXSTA 5 STATUS 5 December 14 2001 Check for reception Nothing recieved check buttons Get pc data Store data Update flags Check input Check to see if down button has been pressed Down button pressed jump to frequency decrement sequence Check to see if up button has been pressed Up button pressed jump to frequency increment sequence Check to see if stereo mono button has been pressed Stereo mono button pressed jump to toggle stereo sequence Check to see if mute button has been pressed Mute button pressed jump to toggle mute sequence Check for 1111 as the first nibble Not 1111 display new frequency Check for 1111 as the first nibble Not 1111 display new frequency Check
10. Visible True Dialog1 Show 1 MSComm1 Output Chr 241 Else MonoStereo Picture MonoStereo DisabledPicture MonoStereoMenu Caption Ch amp ange to Stereo Transmission Dialog1 Caption Home Radio Mono Stereo Select Dialog1 Label1 Visible False Dialog1 Label2 Caption The transmitter is now broadcasting a Mono audio signal Version 1 Service Manual December 14 2001 Page 29 of 63 Home Radio Dialog1 Label2 Visible True Dialog1 Show 1 MSComm1 Output Chr 240 End If End Sub Private Sub MonoStereoMenu_Click If MonoStereo Picture MonoStereo DisabledPicture Then MonoStereo Picture MonoStereo DownPicture MonoStereoMenu Caption Ch amp ange to Mono Transmission Dialog1 Caption Home Radio Mono Stereo Select Dialog1 Label1 Visible False Dialog1 Label2 Caption The transmitter is now broadcasting a Stereo audio signal Dialog1 Label2 Visible True Dialog1 Show 1 MSComm1 Output Chr 241 Else MonoStereo Picture MonoStereo DisabledPicture MonoStereoMenu Caption Ch amp ange to Stereo Transmission Dialog1 Caption Home Radio Mono Stereo Select Dialog1 Label1 Visible False Dialog1 Label2 Caption The transmitter is now broadcasting a Mono audio signal Dialog1 Label2 Visible True Dialog1 Show 1 MSComm1 Output Chr 240 End If End Sub Private MSComm1_OnComm Dim tmpfreq As Variant Select Case MSComm1 CommEvent Errors Case co
11. according to the message carries out appropriate function using the same methods as described in the above functions i e to change from mono to stereo Set Frequency Interface This interface allows the user to manually type in a new frequency It checks for errors It will not accept alphabetic characters or numeric characters smaller than 87 9 or larger than 107 9 Once a valid new frequency is received it sends a message to the transmitter notifying it of the change and displays the new frequency on Main Interface window The following is the list of functions used to accomplish these tasks cmdCancel_Click closes the Set Frequency Interface window and returns control to the Main Interface window without making any changes or sending any messages to the transmitter cmdOK Click checks the user entered date for alphabetic or numeric characters outside the desired range if data is acceptable changes the display on the Main Interface window and sends a message to the transmitter notifying it of the change if data is not acceptable loads the Error Interface window Error Interface The Error Interface is used to alert the user of invalid data that was entered in the Set Frequency Interface window It is simply a dialog box that once closed resets the entry blank on the Set Frequency Interface window so that the data can be reentered Below is the function used to accomplish this task cmdOK_Click resets the ent
12. b 00000100 b 00000100 b 00000100 b 00000100 b 00000100 b 00000100 b 00000100 b 00000100 b 00000100 b 00000100 b 00000100 b 00000100 b 00000100 b 00000100 b 00000100 b 00000100 b 00000100 b 00000100 b 00000100 b 00000100 b 00000100 b 00000100 b 00000100 b 00000100 b 00000100 b 00000100 b 00000100 b 00000100 b 00000100 b 00000100 b 00000100 00000100 b 00000100 b 00000100 b 00000100 Hundreds 1 Tens 0 Hundreds 1 Tens 0 Hundreds 1 Tens 0 Hundreds 1 Tens 0 Hundreds 1 Tens 0 Hundreds 1 Tens 0 Hundreds 1 Tens 0 Hundreds 1 Tens 0 Hundreds 1 Tens 0 Hundreds 1 Tens 0 Hundreds 1 Tens 0 Hundreds 1 Tens 0 Hundreds 1 Tens 0 Hundreds 1 Tens 0 Hundreds 1 Tens 0 Hundreds 1 Tens 0 Hundreds 1 Tens 0 Hundreds 1 Tens 0 Hundreds 1 Tens 0 Hundreds 1 Tens 0 Hundreds 1 Tens 0 Hundreds 1 Tens 0 Hundreds 1 Tens 0 Hundreds 1 Tens 0 Hundreds 1 Tens 0 Hundreds 1 Tens 0 Hundreds 1 Tens 0 Hundreds 1 Tens 0 Hundreds 1 Tens 0 Hundreds 1 Tens 0 Hundreds 1 Tens 0 Hundreds 1 Tens 0 Hundreds 1 Tens 0 Hundreds 1 Tens 0 Hundreds 1 Tens 0 Hundreds 1 Tens 0 Hundreds 1 Tens 0 Hundreds 1 Tens 0 Hundreds 1 Tens 0 Hundreds 1 Tens 0 Hundreds 1 Tens 0 Hundreds 1
13. small wire jumpers that is port 1 is connected to port 16 port 2 is attached to port 15 and so on Ground pins on the 7447 chips PIC microcontroller and MAX 232 chip are connected to this bus The bus itself gets its ground from the voltage regulator circuit Ground Bus 2 This socket is quite different from the first The eight pins facing the middle of the board are tied to ground but the others are not connected The grounds for all of the LED s and pushbuttons on the front of the box as well as the serial cable s ground pin are connected here by pushing the jumpers down into the socket 5 Bus This bus is similar to Ground Bus in that all the pins on the left side are connected to those on the right side with jumpers except for pins and 20 These two pins are connected with 330 resistor and one end is tied to ground rather than 5 volts The other end is connected to pin 5 on the socket that connects to the ones LED this lights up the decimal point All power connections for the system are connected to this bus which gets is connected directly to the output of the voltage regulator circuit Voltage Regulator Socket The voltage regulator is placed in pins 6 7 and 8 facing the middle of the board Nothing else is placed in this socket Voltage Regulator Capacitors Socket The large 1000 F capacitor is placed in pins 1 and 3 the positive end being in pin 1 and the 47 F capacitor is placed in pins 9 and 10
14. transmission Toggle Mute Within this function the mute button is debounced and LED toggled before jumping to a transmit mute setting to PC function The mute button is checked to see if it is still set pressed If it is clear it s checked a second time to ensure the debounce has completed If it is not clear a small 20 millisecond delay is called Once this debounce routine has finished the mute LED is checked If it is set on the LED is turned off for normal transmission Otherwise it is turned on indicating a muted transmission Display Frequency This function sets ports D and E to correctly display the frequency setting Port D displays the decimals and ones while port E contains the tens and hundreds data Initially the high byte of the decimals and ones table location is loaded into the program counter Then the table is called which returns a value a number of steps down the table based in the value stored in the variable freq That is if freq is all zeroes it returns the first value in the table the data needed to display the seven and nine in 87 9 If it is 000000 10 it returns the third value which contains the data needed to display 88 1 and so on The returned value for the decimals and ones is then sent to port D as stated above The tens and hundreds values are displayed in the same manner the high value of the table is loaded the code jumps the same number of values down in this table as it did in the previo
15. 1 Service Manual Page 15 of 63 Home Radio December 14 2001 Main Code The main code section is actually very short First the receive register is checked to see if the frequency has been changed on the PC If it has it jumps to the check frequency section If not it checks all four of the input buttons on the box in sequence If none of the buttons have been pressed then the main code restarts If a button has been pressed the code jumps to a debounce routine for the particular pushbutton that was activated Check Input Here the upper nibble of the input from the PC is checked to see if itis 1111 If it is then this designates a special opcode from the PC has been sent rather than a new frequency If bit 2 is set then the PC is asking for a communication test we jump to a section in the code that sends back exactly what the PC transmitted 11110100 Bit 1 is then checked If bit 1 is set then a mute setting has been received If it is clear a stereo mono setting has been inputted The code then jumps to a section for either a mute or stereo setting depending on this bit Test Communication Here a hexadecimal F4 is sent in response to the PC s call for a communication test Transmission is enabled hex F4 is loaded then it is sent via the transmit register A loop then repeatedly checks the transmit buffer to see if it is empty if it is not a small delay routine is called Once the buffer is emptied and transmission is
16. 2 Ones 0 Decimals 3 Ones 0 Decimals 4 Ones 0 Decimals 5 Ones 0 Decimals 6 Ones 0 Decimals 7 Ones 0 Decimals 8 Ones 0 Decimals 9 Ones 1 Decimals 0 Ones 1 Decimals 1 Ones 1 Decimals 2 Ones 1 Decimals 3 Ones 1 Decimals 4 Ones 1 Decimals 5 Ones 1 Decimals 6 Ones 1 Decimals 7 Ones 1 Decimals 8 Ones 1 Decimals 9 Ones 2 Decimals 0 Ones 2 Decimals 1 Ones 2 Decimals 2 Ones 2 Decimals 3 Ones 2 Decimals 4 Ones 2 Decimals 5 Ones 2 Decimals 6 Ones 2 Decimals 7 Ones 2 Decimals 8 Service Manual December 14 2001 Page 50 of 63 Home Radio tenhun Version 1 retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw org addwf retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw b 00101001 b 00110000 b 00110001 b 00110010 b 00110011 b 00110100 b 00110101 b 00110110 b 00110111 b 00111000 b 00111001 b 01000000 501000001 501000010 501000011 501000100 501000101 501000110 501000111 501001000 501001001 501010000 501010001 501010010 501010011
17. 501010100 501010101 501010110 501010111 501011000 501011001 501100000 501100001 501100010 501100011 501100100 501100101 501100110 501100111 52701101000 501101001 52701110000 501110001 501110010 b 01110011 b 01110100 b 01110101 b 01110110 b 01110111 b 01111000 b 01111001 0x0600 PCL F b 0000001 0 b 0000001 0 500000010 500000010 500000010 500000010 500000010 500000010 500000010 500000010 Ones 2 Decimals 9 Ones 3 Decimals 0 Ones 3 Decimals 1 Ones 3 Decimals 2 Ones 3 Decimals 3 Ones 3 Decimals 4 Ones 3 Decimals 5 Ones 3 Decimals 6 Ones 3 Decimals 7 Ones 3 Decimals 8 Ones 3 Decimals 9 Ones 4 Decimals 0 Ones 4 Decimals 1 Ones 4 Decimals 2 Ones 4 Decimals 3 Ones 4 Decimals 4 Ones 4 Decimals 5 Ones 4 Decimals 6 Ones 4 Decimals 7 Ones 4 Decimals 8 Ones 4 Decimals 9 Ones 5 Decimals 0 Ones 5 Decimals 1 Ones 5 Decimals 2 Ones 5 Decimals 3 Ones 5 Decimals 4 Ones 5 Decimals 5 Ones 5 Decimals 6 Ones 5 Decimals 7 Ones 5 Decimals 8 Ones 5 Decimals 9 Ones 6 Decimals 0 Ones 6 Decimals 1 Ones 6 Decimals 2 Ones 6 Decimals 3 Ones 6 Decimals 4 Ones 6 Decimals 5 Ones 6 Decimals 6 Ones 6 Decimals 7 Ones 6 Decimals 8 Ones 6 Decimals 9 Ones 7 D
18. 510010111 510011000 510011001 500000000 500000001 500000010 500000011 500000100 500000101 500000110 00000111 500001000 500001001 500010000 500010001 500010010 b 00010011 b 00010100 b 00010101 00010110 b 00010111 b 00011000 b 00011001 b 00100000 b 00100001 b 00100010 00100011 00100100 b 00100101 b 00100110 b 00100111 b 00101000 Ones 5 Decimals 9 Ones 6 Decimals 0 Ones 6 Decimals 1 Ones 6 Decimals 2 Ones 6 Decimals 3 Ones 6 Decimals 4 Ones 6 Decimals 5 Ones 6 Decimals 6 Ones 6 Decimals 7 Ones 6 Decimals 8 Ones 6 Decimals 9 Ones 7 Decimals 0 Ones 7 Decimals 1 Ones 7 Decimals 2 Ones 7 Decimals 3 Ones 7 Decimals 4 Ones 7 Decimals 5 Ones 7 Decimals 6 Ones 7 Decimals 7 Ones 7 Decimals 8 Ones 7 Decimals 9 Ones 8 Decimals 0 Ones 8 Decimals 1 Ones 8 Decimals 2 Ones 8 Decimals 3 Ones 8 Decimals 4 Ones 8 Decimals 5 Ones 8 Decimals 6 Ones 8 Decimals 7 Ones 8 Decimals 8 Ones 8 Decimals 9 Ones 9 Decimals 0 Ones 9 Decimals 1 Ones 9 Decimals 2 Ones 9 Decimals 3 Ones 9 Decimals 4 Ones 9 Decimals 5 Ones 9 Decimals 6 Ones 9 Decimals 7 Ones 9 Decimals 8 Ones 9 Decimals 9 Ones 0 Decimals 0 Ones 0 Decimals 1 Ones 0 Decimals
19. Home Radio December 14 2001 Home Rad FM Audio Link Authors Michael Guinn Christopher Johns Perry Minigh and Travis Masoner Project Sponsor Dr Valenti Service Manual December 14 2001 Version 1 Service Manual Page 1 of 63 Home Radio December 14 2001 Table of Contents 1 Ditroductioi s 2 Subsystem 6 PC Software b 5 5555 9 PIC d Transmitter Subsystem 10 3 Circuit Schematics amp Software Coding 11 8 PC Coden coo i eerie b PIC Subsystem Schematics 13 c PIC Subsystem Code 14 d Transmitter Subsystem Schematic 15 Parts 6 lO 4 Adjustable 17 a Transmitter Subsystem Potentiometer 18 b Transmitter Subsystem Inductor 19 5 Troubleshooting 7005 sua ch ssoe ense o cose 20 Version 1 Service Manual Page 2 of 63 Home Radio December 14 2001 1 Introduction Welcome to the Home Radio Audio Link Service Manual This document is created to explain to a user with a background in computers and electronics how the system operates and how to repair the system should it fail In the following pages we will discus
20. Select Dialog1 Label1 Visible False Dialog1 Label2 Caption The transmitter is now broadcasting a Stereo audio signal Dialog1 Label2 Visible True Dialog1 Show 1 Case 242 Mute Transmitter formclose True MuteButton Picture MuteButton DisabledPicture Dialog1 Caption Home Radio Mute Transmission Dialog1 Label1 Visible True Dialog1 Label2 Visible False Dialog1 Show 1 MuteMenu Caption Sou amp nd Transmitter Case 243 Sound Transmitter MuteButton Picture MuteButton DownPicture MuteMenu Caption M amp ute Transmitter End Select End If Case comEvSend _ There are SThreshold number of characters in the transmit buffer Case comEvEOF EOF charater was found in the input stream End Select End Sub Private Sub MuteButton_Click If MuteButton Picture MuteButton DisabledPicture Then MuteButton Picture MuteButton DownPicture MuteMenu Caption M amp ute Transmitter MSComm1 Output Chr 243 Else MuteButton Picture MuteButton DisabledPicture Dialog1 Caption Home Radio Mute Transmission Dialog1 Label1 Visible True Dialog1 Label2 Visible False Dialog1 Show 1 MuteMenu Caption Sou amp nd Transmitter MSComm1 Output Chr 242 End If End Sub Private Sub MuteMenu Click If MuteButton Picture MuteButton DisabledPicture Then MuteButton Picture MuteButton DownPicture MuteMenu Caption M amp ute Transmitter MSComm1 Output Chr 243 Else MuteButton Pi
21. dialog appears and reports the success of the test The functions described below are used to carry out these tasks Timerl Timer waits to receive a signal from the transmitter for 3000 milliseconds if nothing is received or if communication was verified displays the correct message CancelButton Click closes the Communications Test Interface and the entire GUI OKButton Click only enabled after a test has succeeded or failed upon test failure runs the test again upon test success closes Communications Test Interface and returns control to the Main Interface window Dialog Interface The Dialog Interface is used to display alert messages to the user upon the transmitter changing modes i e changing from mono to stereo It serves no other purpose and closes after 2500 milliseconds This is done using the following function Timerl Timer after 2500 milliseconds closes the Dialog Interface and returns control to the Main Interface window Version Information Interface Version 1 Service Manual Page 8 of 63 Home Radio December 14 2001 The Version Information Interface is used to display the current version information of the Home Radio GUI It serves no other purpose and after it is close it returns control to the Main Interface window This task is done using the following function cmdOK Click closes the Version Information Interface and returns control to the Main Interface win
22. finished transmission is disabled The program then returns to the main code PC Set Stereo This function changes the stereo setting based on input from the PC Bit 0 of the data sent from the PC is checked If the bit is set stereo is turned on if it is clear the stereo LED is turned off PC Set Mute This function changes the mute setting based on input from the PC Bit 0 of the data sent from the PC is checked If the bit is set mute is turned on if it is clear the mute LED is turned off Version 1 Service Manual Page 16 of 63 Home Radio December 14 2001 Restore Frequency This function is called from either test communication PC set stereo or PC set mute since an opcode was sent rather than a new frequency The previous frequency which was stored in the variable oldfrq is loaded back into the variable freq resetting the frequency back to what it was before the PC data was received We jump back to the main code Decrement Frequency Within this function the down button is debounced and the frequency decremented before jumping to a transmit frequency to PC function The down button is checked to see if it is still set pressed If it is clear it s checked a second time to ensure the debounce has completed If it is not clear a small 20 millisecond delay is called Once this debounce routine has finished each bit of the frequency is checked to see if it is the minimum value all eight bits of the variable freq zer
23. for 1111 as the first nibble Not 1111 display new frequency Check for 1111 as the first nibble Not 1111 display new frequency Check bit 2 Test PC communication Check bit 1 Mute setting check it Stereo mono setting check it Register Page 1 Enable transmission Register Page 0 Load test value for transmission Send test value Register Page 1 until transmit buffer is empty Register Page 0 Register Page 1 Disable transmission Register Page 0 Service Manual Page 42 of 63 Home Radio December 14 2001 goto main Restart loop pcster btfss it set to stereo or mono goto setmon Mono turn off LED setstr bsf SterL Stereo turn on mono stereo LED goto restf Restore frequency setmon bcf SterL Turn off mono stereo LED goto restf Restore frequency PC Set Mute pcmute _ btfss 1 mute on off goto setmun Mute turn on LED setmuf bcf MuteL Mute off turn off LED goto restf Restore frequency setmun bsf MuteL on mute LED goto restf Restore frequency Restore Freq restf movfw oldfrq Load old frequency movwf freq Restore since it was not actually changed goto main Restart loop Decrement Freq freqd btfss DownB 15 the down button still pressed goto 1 Yes go back movlw 0x00C Wait for debounce movwf Dlay Delay 20 msecs 0 007 btfss DownB ls the down button still pressed goto 6 Yes go back
24. to the other circuit components as diagrammed in Chapter 3 7447 BCD Decoder Sockets The inputs to these sockets connect to the PIC and the outputs are tied to the 330 W resistor packs Power and ground as with the other chips are drawn from the power and ground buses 330 W Resistor Packs The resistors connect the pins on the left side to the pins directly across from them on the right side Only the 7447 decoders and seven segment displays are connected to these sockets Seven Segment Displays These sockets are not stuck in the perf board rather they are simply wired to the resistor packs and hang from the board This permits ease of connection to the actual displays which are glued to the transmitter box itself LED Pushbutton 1 0 Socket Only pins 1 through 6 are used in this socket The frequency up button plugs into pin 1 and the frequency down button is plugged into pin 2 Toggle stereo mono plugs into pin 3 while toggle mute is placed into pin 4 The positive end of the stereo mono LED connects to pin 5 of this socket leaving pin 6 which connects to the mute LED On the underside of the perf board these pins are tied to the PIC as specified in the circuit diagram Version 1 Service Manual Page 14 of 63 Home Radio December 14 2001 2c PIC Software The code described in this section is listed in section 3d of this Service Manual The following information steps through the code function by fun
25. with the positive leg placed in 10 No other connections are made into this socket Version 1 Service Manual Page 12 of 63 Home Radio December 14 2001 Voltage Regulator Circuit The following diagram illustrates the setup of the 12 to 5 volt converter The diode input is soldered to the 12 volt input plug that connects to the wall jack or cigarette lighter adapter The five volt output connects to the power bus 1000 F Figure 2 Voltage Regulator Circuit Miscellaneous Socket This socket contains several items with varying functions The top ten pins 1 through 5 and 16 to 20 contain the 5 capacitors needed to operate the MAX 232 chip The positive capacitor side is the right side of the socket and the negative the left side The bottom four pins 9 to 12 hold the two capacitors connected to the PIC s oscillator The two pins directly above them 8 and 13 hold the capacitor itself Pins 7 and 14 hold the 1 k resistor needed to connect PIC pin 1 MCLR to 5 volts pin 7 is connected to the PIC and pin 14 connected to the power bus This leaves pins 6 and 15 which are not connected PIC 16F877 Socket Unlike the other sockets all connections to this circuit are soldered The PIC connects to the various other components in the circuit as shown in the circuit diagram in Chapter 3 Version 1 Service Manual Page 13 of 63 Home Radio December 14 2001 MAX 232 Socket This socket and chip connect
26. 0 Ones 7 Decimals 9 Ones 8 Decimals 0 Ones 8 Decimals 1 Ones 8 Decimals 2 Ones 8 Decimals 3 Ones 8 Decimals 4 Ones 8 Decimals 5 Ones 8 Decimals 6 Ones 8 Decimals 7 Ones 8 Decimals 8 Service Manual December 14 2001 Page 48 of 63 Home Radio Version 1 retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw b 10001001 b 10010000 b 10010001 b 10010010 b 10010011 b 10010100 b 10010101 b 10010110 b 10010111 b 10011000 b 10011001 b 00000000 b 00000001 500000010 500000011 500000100 500000101 500000110 500000111 500001000 500001001 500010000 500010001 500010010 500010011 500010100 500010101 500010110 500010111 500011000 500011001 500100000 500100001 500100010 500100011 500100100 500100101 500100110 500100111 500101000 500101001 500110000 500110001 500110010 500110011 500110100 500110101 500110110 b 00110111 b 00111000 b 00111001 b 01000000 b 01000001 b 01000010 501000011 5
27. 01000100 501000101 501000110 b 01000111 b 01001000 b 01001001 b 01010000 b 01010001 b 01010010 b 01010011 b 01010100 b 01010101 b 01010110 b 01010111 b 01011000 Ones 8 Decimals 9 Ones 9 Decimals 0 Ones 9 Decimals 1 Ones 9 Decimals 2 Ones 9 Decimals 3 Ones 9 Decimals 4 Ones 9 Decimals 5 Ones 9 Decimals 6 Ones 9 Decimals 7 Ones 9 Decimals 8 Ones 9 Decimals 9 Ones 0 Decimals 0 Ones 0 Decimals 1 Ones 0 Decimals 2 Ones 0 Decimals 3 Ones 0 Decimals 4 Ones 0 Decimals 5 Ones 0 Decimals 6 Ones 0 Decimals 7 Ones 0 Decimals 8 Ones 0 Decimals 9 Ones 1 Decimals 0 Ones 1 Decimals 1 Ones 1 Decimals 2 Ones 1 Decimals 3 Ones 1 Decimals 4 Ones 1 Decimals 5 Ones 1 Decimals 6 Ones 1 Decimals 7 Ones 1 Decimals 8 Ones 1 Decimals 9 Ones 2 Decimals 0 Ones 2 Decimals 1 Ones 2 Decimals 2 Ones 2 Decimals 3 Ones 2 Decimals 4 Ones 2 Decimals 5 Ones 2 Decimals 6 Ones 2 Decimals 7 Ones 2 Decimals 8 Ones 2 Decimals 9 Ones 3 Decimals 0 Ones 3 Decimals 1 Ones 3 Decimals 2 Ones 3 Decimals Ones 3 Decimals 4 Ones 3 Decimals 5 Ones 3 Decimals 6 Ones 3 Decimals 7 Ones 3 Decimals 8 Ones 3 Decimals 9 Ones 4 Decimals 0 Ones
28. 1 Visible True textwindow 1 Case 2 Version 1 Service Manual December 14 2001 Page 33 of 63 Home Radio December 14 2001 Text2 Visible True textwindow 2 Case 3 Text3 Visible True textwindow 3 Case 4 Text4 Visible True textwindow 4 Case 5 Text5 Visible True textwindow 5 Case 7 Text6 Visible True textwindow 7 Case 8 Text7 Visible True textwindow 8 Case 9 Text8 Visible True textwindow 9 End Select End If End Sub Private Sub Command3 Click Me Hide End Sub Private Sub Form Load fwd 0 textwindow 0 End Sub Private Sub List1_Click Select Case List1 ListIndex Case 0 6 fwd 0 textwindow 0 Case 1 List1 Visible False Text1 Visible True textwindow 1 Case 2 List1 Visible False Text2 Visible True textwindow 2 Case 3 List1 Visible False Text3 Visible True textwindow 3 Case 4 List1 Visible False Text4 Visible True textwindow 4 Case 5 List1 Visible False Text5 Visible True textwindow 5 Case 7 List1 Visible False Text6 Visible True textwindow 7 Case 8 List1 Visible False Text7 Visible True textwindow 8 Case 9 List1 Visible False Text8 Visible True textwindow 9 Version 1 Service Manual Page 34 of 63 Home Radio December 14 2001 End Select End Sub Splash Screen Form Code Private Sub Form_KeyPress KeyAscii As Integer Unload Me End Sub Private Sub Form_Load Ibl
29. 500000011 500000011 500000011 500000011 500000011 500000011 500000011 500000011 500000011 500000011 500000011 500000011 500000011 500000011 500000011 500000011 500000011 500000011 500000011 500000011 500000011 500000011 500000011 500000011 500000011 500000011 500000011 500000011 500000011 500000011 500000011 500000011 500000011 500000011 500000011 Hundreds 0 Tens 8 Hundreds 0 Tens 8 Hundreds 0 Tens 8 Hundreds 0 Tens 8 Hundreds 0 Tens 8 Hundreds 0 Tens 8 Hundreds 0 Tens 8 Hundreds 0 Tens 8 Hundreds 0 Tens 8 Hundreds 0 Tens 8 Hundreds 0 Tens 8 Hundreds 0 Tens 9 Hundreds 0 Tens 9 Hundreds 0 Tens 9 Hundreds 0 Tens 9 Hundreds 0 Tens 9 Hundreds 0 Tens 9 Hundreds 0 Tens 9 Hundreds 0 Tens 9 Hundreds 0 Tens 9 Hundreds 0 Tens 9 Hundreds 0 Tens 9 Hundreds 0 Tens 9 Hundreds 0 Tens 9 Hundreds 0 Tens 9 Hundreds 0 Tens 9 Hundreds 0 Tens 9 Hundreds 0 Tens 9 Hundreds 0 Tens 9 Hundreds 0 Tens 9 Hundreds 0 Tens 9 Hundreds 0 Tens 9 Hundreds 0 Tens 9 Hundreds 0 Tens 9 Hundreds 0 Tens 9 Hundreds 0 Tens 9 Hundreds 0 Tens 9 Hundreds 0 Tens 9 Hundreds 0 Tens 9 Hundreds 0 Tens 9 Hundreds 0 Tens 9 Hundreds 0 Tens 9 Hundreds 0 Tens 9 Hu
30. Clock_Minutes Case 0 Minutes Picture LoadPicture A 0 bmp Version 1 Service Manual December 14 2001 Page 26 of 63 Home Radio Case 1 Minutes Picture LoadPicture A 1 bmp Case 2 Minutes Picture LoadPicture A 2 bmp Case 3 Minutes Picture LoadPicture A 3 bmp Case 4 Minutes Picture LoadPicture A 4 bmp Case 5 Minutes Picture LoadPicture A 5 bmp Case 6 Minutes Picture LoadPicture A 6 bmp Case 7 Minutes Picture LoadPicture A 7 omp Case 8 Minutes Picture LoadPicture A 8 bmp Case 9 Minutes Picture LoadPicture A 9 bmp End Select Else AudioPlayer Clock_Minutes 0 Minutes Picture LoadPicture A 0 bmp AudioPlayer Clock_Hours AudioPlayer Clock_Hours 1 If AudioPlayer Clock_Hours lt 6 Then Select Case AudioPlayer Clock_Hours Case 0 Hours Picture LoadPicture A 0 omp Case 1 Hours Picture LoadPicture A 1 omp Case 2 Hours Picture LoadPicture A V2 bmp Case 3 Hours Picture LoadPicture A 3 omp Case 4 Hours Picture LoadPicture A M bmp Case 5 Hours Picture LoadPicture A 5 omp End Select Else AudioPlayer Clock_Hours 0 Hours Picture LoadPicture A 0 omp End If End If End If End If End Sub Audio Selection Code Private Sub List1_Click Select Case List1 ListIndex Case 0 AudioPlayer DeviceType 1 AudioPlayer Open Enabled False AudioPlayer Prev Enabled True AudioPla
31. Freq7 freq NOoORWNM O define DownB PORTB 0 define UpB PORTB define SterB PORTB 2 define MuteB PORTB 3 define SterL PORTB 6 define MuteL PORTB 7 Code Origin org 0 goto start Version 1 Service Manual Page 40 of 63 Home Radio Port Setup start bcf bcf clrf clrf clrf clrf clrf bsf bcf movlw movwf movlw movwf movlw movwf movlw movwf movlw movwf movlw movwf movlw movwf movlw movwf bcf bcf bsf bsf goto runi call movlw movwf bsf bcf goto Main Code main movfw Version 1 STATUS 5 STATUS 6 PORTA PORTB PORTC PORTD PORTE STATUS 5 STATUS 6 0x06 ADCON1 0x00 TRISA Ox3F TRISB Ox7F OPTION REG OxFE TRISC 0x00 TRISD 0x00 TRISE 081h SPBRG TXSTA 4 STATUS 5 RCSTA 7 RCSTA 4 runi rdata b 00000000 freq SterL MuteL trans freq 0x080 0x080 0x080 0x080 0x080 0x080 0x080 Register Page 0 Initialize data ports Register Page 1 Disable A D Port A Output PortB I O Pullups Enabled Enable pull ups 0x080 PortC Serial PC Communication PortD Output PortE Output Set baud rate to 2400 Asynchronous Register Page 0 Asynchronous Enable reception Load previous frequency Store previous frequency Load previous stereo mono setting Load previous mute setting Transmit previous frequency to PC old frequency Service Manual December 14 2001
32. Home Radio December 14 2001 4a Transmitter Subsystem Potentiometers The potentiometers seen in Figure 5 are used to attenuate the audio signal before modulating it onto the carrier frequency generated by the BH1415F The 100K potentiometers connected to the right and left channels function exactly the same and are used to attenuate the audio input such that information is not lost when passed through the audio limiter circuit that is inside the BH1415F If the audio input level is too high then the signal will be clipped by the BH1415F causing a loss of information The 10K potentiometer connected to pin 5 of the BH1415F is designed to allow attenuation of the multiplexed stereo or mono signal that is generated by the 1415 This can be adjusted to affect the modulation of the signal onto the carrier frequency Version 1 Service Manual Page 59 of 63 Home Radio December 14 2001 4b Transmitter Subsystem Inductor The FEM10C 3F6 manufactured by Sumida Corporation is used in the voltage controlled oscillator that is a necessary for successful operation of the Bh1415F This inductor should only be tuned with a proper tuning wand and can be varied to change the oscillation frequency of the VCO This can be used to calibrate the frequency such that it matches the serially selected frequency Version 1 Service Manual Page 60 of 63 Home Radio December 14 2001 5 Troubleshooting Troubleshooting the Transmitter Output F
33. Tens 0 Hundreds 1 Tens 0 Hundreds 1 Tens 0 Hundreds 1 Tens 0 Hundreds 1 Tens 0 Hundreds 1 Tens 0 Hundreds 1 Tens 0 Hundreds 1 Tens 0 Hundreds 1 Tens 0 Hundreds 1 Tens 0 Service Manual December 14 2001 Page 54 of 63 December 14 2001 3d Transmitter Subsystem Schematic Home Radio gt gt 3001 3101 10 39 8 4955 i 93 20133 an angi 39061 44002 Lin mi ppp mim 6 2 e s Fl s Ez o 1 0 TE soni YNNILNY sl S soa angl 310 55 63 Figure 5 Transmitter Subsystem Schematic Service Manual Version 1 Home Radio December 14 2001 R CH INPUT L CH INPUT PRE EMPHASIS TIME CONSTANT PRE EMPHASIS TIME CONSTANT LPF TIME CONSTANT bo LPF TIME CONSTANT FILTER PILOT SIGNAL ADJUST COMPOSITE SIGNAL OUTPUT AUDIO MUTING BH1415F 6 DATA PLL PHASE DETECTOR OUTPUT CLOCK vee 8 CHIP ENABLE RF OSCILLATOR 9 OSCILLATOR GND hol OSCILLATOR RF OUTPUT PLL Vee Figure 6 Pin Descriptions for BH1415F Version 1 Service Manual Page 56 of 63 Home Radio 3e Parts List Transmitter Components
34. Version Caption Version amp amp amp App Minor amp amp App Revision End Sub Private Sub Frame1_Click Unload Me End Sub Private Sub IblLicenseTo Click End Sub Private Sub Timer Timer Unload frmSplash End Sub Version 1 Service Manual Page 35 of 63 Home Radio December 14 2001 3b PIC Subsystem Schematics This section contains four schematics that display all the connections within the PIC subsystem The first details the PIC s power and ground connections the second lists connections that need to be made to the PC and the transmitter subsystem the third displays how the PIC is connected to the four 7447 BCD decoders and the final one shows how all the connections are made between the 7447 s and seven segment displays the same four all four sets MCLR PIC 16F877 Vdd Vss OSC1 OSC2 Figure 1 PIC Power and Ground Connections Version 1 Service Manual Page 36 of 63 Home Radio PIC 16F877 MAX232 Vcc GND T1 Out R1 In R1 Out T1 In T2 In R2 Out 9 Figure 2 PIC Connections to and Transmitter IC Pin 15 IC Pin 15 IC Pin 15 IC Pin 15 0 1 0 1 T2 Out a nam Serial Cable Connection Version 1 Service Manual December 14 2001 0 1 F Page 37 of 63 Home Radio December 14 2001 5 GND 7447 5 RBI GND 7447 Hundreds PIC 16F877
35. again ifndef Debug Skip small loop if Debug is defined addlw 1 Increment the delay count btfsc STATUS Z low byte in w is not equal to zero then loop decfsz Dlay goto 5 else decfsz Dlay Else short loop goto 3 endif btfsc Check frequency to ensure it is not already at min value goto freqd2 btfsc 1 goto freqd2 btfsc Freq2 goto freqd2 Version 1 Service Manual Page 43 of 63 Home Radio December 14 2001 freqd2 frequ2 Toggle Stereo Version 1 btfsc goto btfsc goto btfsc goto btfsc goto btfsc goto movlw movwf goto decf goto btfss goto movlw movwf movlw btfss goto ifndef else endif btfsc goto btfsc goto btfsc goto btfss goto btfsc goto btfsc goto btfss goto btfss goto movlw movwf goto incf goto freqd2 Freq4 freqd2 Freq5 freqd2 Freq6 freqd2 Freq7 freqd2 b 11001000 Min value wrap back around to max value freq trans Transmit new frequency freq Done debouncing decrement frequency trans Transmit new frequency UpB Is the up button still pressed 1 Yes go back 0x00C for debounce Dlay Delay 20 msecs 0 007 UpB Is the up button still pressed 6 Yes go back again Debug Skip small loop if Debug is defined addlw 1 Increment the delay count btfsc STATUS Z low byte in w is not equal to zero then loop decfsz Dlay goto 5 decfsz Dlay Else short loop goto 3
36. ase AudioPlayer DeviceType Case 0 CommonDialog1 Filter mp3 mp3 CommonDialog1 ShowOpen If CommonDialog1 FileName lt gt Then AP FileName CommonDialog1 FileName AP Play End If Case 1 CommonDialog1 Filter cda cda CommonDialog1 ShowOpen If CommonDialog1 FileName lt gt Then MMControl1 FileName CommonDialog1 FileName MMControl1 Command Play End If Case 2 CommonDialog1 Filter wav wav CommonDialog1 ShowOpen If CommonDialog1 FileName lt gt Then AP FileName CommonbDialog1 FileName AP Play End If End Select If CommonDialog1 FileName lt gt Then Hours Picture LoadPicture AA0 bmp Minutes Picture LoadPicture A 0 omp Tens Picture LoadPicture A 0 bmp Ones Picture LoadPicture AA0 bmp Timer1 Enabled True End If End Sub Private Sub Pause_Click Timer1 Enabled False sure device has been selected If DeviceType 1 Then AudioSelection Show 1 End If Select Correct Device If AudioPlayer DeviceType 0 Then AP Pause Else MMControl1 Command Pause End If End Sub Private Sub Play Click Be sure device has been selected If DeviceType 1 Then AudioSelection Show 1 End If Select Correct Device If AudioPlayer DeviceType 0 Then If AP FileName lt gt Then AP Play If AudioPlayer Counter 0 Then Hours Picture LoadPicture A 0 omp Minutes Picture LoadPicture A 0 bmp Tens Picture LoadPicture A 0 bmp Ones Pictu
37. ations port control to read the entire buffer on input opens port 1 initializes testcomvar which is used to test communications with the transmitter OpenPlayerCommand_Click loads the Audio Player Interface window ExitCommand_Click closes the GUI MuteMenu Click sends a message to transmitter to change mode of operation changes the display on the tool bar to fit the current state of the transmitter changes the description of the function on the drop down menus to fit the current state of the transmitter loads the Dialog Interface window with the appropriate message Service Manual Page 5 of 63 Home Radio December 14 2001 Version 1 SetFrequencyMenu_Click loads the Set Frequency Interface window MonoStereoMenu_Click sends a message to transmitter to change mode of operation changes the display on the tool bar to fit the current state of the transmitter changes the description of the function on the drop down menus to fit the current state of the transmitter loads the Dialog Interface window with the appropriate message Click sends a message to the transmitter signaling a communications test loads the Communications Test Interface window AboutCommand Click loads the Version Information Interface window SupportCommand Click loads the User Help Interface window OpenPlayerButton_Click loads the Audio Player Interface window ChangeFreqButton_Click load
38. cing the MAX 232 chip If that doesn t work verify connections and possibly try a new PIC Version 1 Service Manual Page 62 of 63 Home Radio December 14 2001 Troubleshooting the PC software To troubleshoot any problem with the Home Radio software open the file cpe481 prj vbp in Microsoft Visual Basic 6 0 On the drop down menu click and then Start The program will then run just like an executable Repeat the steps taken before the error originally appeared and try to reproduce it If the program encounters a bug it will alert the user of a problem and highlight the section of code that is wrong From there the user can access the MSDN help files to solve the problem Version 1 Service Manual Page 63 of 63
39. ction giving an more in depth explanation than can be realized from simply reading the commenting in the file Processor Declarations Since we are using a PIC16F877 we select it and the corresponding include file here Register Usage Dlay refers to a delay used to debounce the pushbuttons Freq count and oldfrq are simple register variables used to store a single byte of data each The define freq declarations assign a name to represent each bit of the stored frequency value This allows for easy bit checking The following six define statements assign a name to the frequency up button frequency down button stereo button mute button stereo LED and mute LED for easy checking and setting Code Origin The org call starts the code at location 0 the first available spot Port Setup At register page 0 all five I O ports are cleared for initialization Then at register page 1 Analog to Digital conversion for port A is disabled port A is set to output port B is set up for input at bits 0 through 5 and output at bits 6 and 7 and ports C D and E are set for output The serial transmit and receive pins on port C are activated and set to asynchronous transmission at a baud rate of 2400 Receive is finally enabled at register page 0 Run Once at Start This section initializes the frequency to 87 9 MHz and enables stereo transmission while disabling the mute setting It also sends this frequency setting to the PC Version
40. ctually supplying audio to the BH1415F by looking at pins 1 and 2 Troubleshooting the PIC System Displayed frequency on box does not match the one displayed by the PC or is garbage Turn off the power to the Home Radio system and close the program on the PC Restart the program and then turn the power on to the transmitter This should reset everything to 87 9 MHz Same as above but restart the PC before restarting the program and turning on the transmitter This may fix problems caused by an unreliable serial port Make sure the sockets attached to the back of the seven segment displays are attached correctly Verify that wire wrap connections from the sockets to the resistor packs are good Verify the connections from the resistor packs to the BCD decoders Verify the connections from the BCD decoders to the PIC Version 1 Service Manual Page 61 of 63 Home Radio December 14 2001 Touch the problematic BCD decoder s and the PIC after the system has been turned on for a few seconds Are they hot If so the problematic component will likely need to be replaced My PIC went bad and I m can t get the new one to program correctly Make sure the watchdog timer is turned off when you program Ensure that low voltage program enable is disabled Be sure code protect is turned off if this is not the case you ve wasted another PIC Pushbuttons don t always work Verify that the solder connections on the problematic pus
41. cture MuteButton DisabledPicture MuteMenu Caption Sou amp nd Transmitter Dialog1 Caption Home Radio Mute Transmission Dialog1 Label1 Visible True Dialog1 Label2 Visible False Dialog1 Show 1 MSComm1 Output Chr 242 End If End Sub Private Sub OpenPlayerButton_Click AudioPlayer Show 1 End Sub Version 1 Service Manual December 14 2001 Page 31 of 63 Home Radio Private Sub OpenPlayerCommand Click AudioPlayer Show 1 End Sub Private Sub SetFrequencyMenu Click Form2 Show 1 End Sub Private Sub Timer Unload frmSplash End Sub Private Sub SplashScreenOption Click If SplashScreenOption Checked True Then SplashScreenOption Checked False Else SplashScreenOption Checked True End If End Sub Private Sub SupportCommand Click Form4 Show 1 End Sub Private Sub TestCMenu Click MSComm1 Output Chr 244 Dialog Show 1 End Sub Private Sub UplncrementButton Click If FreqText Text 107 9 Then FreqText Text FreqText Text 0 1 If FreqText Text Int FreqText Text 0 Then Tmp FreqText Text amp 0 FregText Text Tmp End If Else FreqText Text 87 9 End If TxFreq End Sub Private Sub WindowOption Click If WindowOption Checked True Then WindowOption Checked False Else WindowOption Checked True End If End Sub Public Sub TxFreq Dim freq As Variant freq FreqText Text freq freq 10 879 MSComm1 Outp
42. dow Audio Player Interface The Audio Player Interface is used to play audio files located on the PC It is capable of playing three file types wav mp3 and cda If the device selected is the CD player then it can advance between tracks otherwise each song must be individually opened This is done using the following functions 2 Form Load initialize a variable that keeps track of the opened device initializes the devices to be used initializes the variables used to display the music timer Mode Click loads the Audio Selection Interface Open Click when enabled disabled when the selected device is a CD ROM loads common dialog box that opens files of the desired type wav or mp3 Timerl Timer loads the correct bmp file according to how much time has passed since the audio player was started operates the music timer Prev Click rewinds the current track if the track is rewound plays the previous track resets music timer Play Click plays the currently loaded track or file signals the music timer to begin Pause Click stops the play of the currently loaded track or disables the music timer keeps the display the same Stop Click stops the play of the currently loaded track or file and rewinds it disables the music timer resets the display Next Click plays the next track on the CD Version 1 Service Manual Page 9 of 63
43. e antenna The complete schematic for the transmitter subsystem can be seen in section 3d of this service manual Nonstandard components resistors capacitors crystals etc are listed below Description Manufacturer Part Darlington Transistor ROHM 25 20625 Varactor Diode TOKO 1471 Band Pass Filter SOSHIN GFWB3 Variable Inductor SUMIDA FEM10C 3F6 Stereo Modulator RF generator ROHM 1415 RF Amplifier RF Micro Devices RF2334 Audio Input The audio input is done through standard RCA Jacks One being a left channel and the other the right channel This input is filtered by the BH1415F chip with a low pass filter before being added L R and subtracted L R by the chip The multiplexed stereo or mono when mono is on output is observed at pin 5 of the BH1415F This is connected to a potentiometer for desired attenuation and fed to the rest of the circuit Phase Lock Loop PLL The 1415 chip implements a phase lock loop system that contains some components that are off chip The goal of the PLL is to allow the user to serially select the operating frequency and to adjust the RF output frequency accordingly The serial data is input via pins 15 16 and 17 on the BH1415F For specifics on programming the serial input please refer to the BH1415F data sheet included with this manual Voltage Controlled Oscillator The voltage controlled oscillator VCO portion that is contained outside of the BH1415F consists
44. ecimals 0 Ones 7 Decimals 1 Ones 7 Decimals 2 Ones 7 Decimals 3 Ones 7 Decimals 4 Ones 7 Decimals 5 Ones 7 Decimals 6 Ones 7 Decimals 7 Ones 7 Decimals 8 Ones 7 Decimals 9 Hundreds 0 Tens 8 Hundreds 0 Tens 8 Hundreds 0 Tens 8 Hundreds 0 Tens 8 Hundreds 0 Tens 8 Hundreds 0 Tens 8 Hundreds 0 Tens 8 Hundreds 0 Tens 8 Hundreds 0 Tens 8 Hundreds 0 Tens 8 Service Manual December 14 2001 Page 51 of 63 Home Radio Version 1 retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw b 00000010 b 00000010 b 00000010 b 00000010 b 00000010 b 00000010 b 00000010 b 00000010 b 00000010 00000010 b 00000010 500000011 500000011 500000011 500000011 500000011 500000011 500000011 500000011 500000011 500000011 500000011 500000011 500000011 500000011 500000011 500000011 500000011 500000011 500000011 500000011 500000011 500000011 500000011 500000011
45. hbutton have not broken Ensure the wires on the pushbutton are pressed fully into the target socket Verify the connection from the socket to the PIC is wire wrapped correctly on the socket side and has a good solder connection on the PIC side System won t turn on Make sure the oscillator is fully pressed into the socket Verify its connections to the PIC Verify solder connections from power jack to voltage regulator circuit Ensure the capacitors for the voltage regulator circuit have the correct polarization Check the solder connections on the diode Ensure front of voltage regulator faces the center of the board if it does not the voltage regulator may have burned up and will need to be replaced Make sure the PIC is plugged into the system correctly Touch it when the system is plugged in for a few seconds is it hot If so it has most likely burned up and will need to be replaced Serial connection with PC fails even though everything is plugged in correctly Verify solder connections on the inside of the box from the jack to the system Ensure the 5 capacitors for the MAX 232 chip are plugged fully into the socket and in the correct places Ensure pins 25 and 26 on the PIC as well as pins 11 and 12 have 5 volts across them Ensure pins 13 and 14 on the MAX 232 chip have negative voltages between 5 and 25 volts Using an oscilloscope verify transmission on the above pins If none of the above has worked try repla
46. it register Otherwise hexadecimal F3 the opcode for normal transmission is loaded to the transmit buffer Again a loop repeatedly checks the transmit buffer A delay is called until the buffer is empty at which point the transmission is disabled since it is finished We then jump back to the main code Delay This is called by all of the transmit routines Hexadecimal FF is loaded into a counter variable and it is repeatedly decremented though a loop until it is equal to zero The program then returns to its previous location Data Read This function is not currently used Data Write This function is not currently used Version 1 Service Manual Page 19 of 63 Home Radio December 14 2001 Decimals and Ones This table begins at register address 300 to avoid paging errors in the high byte of the program counter It returns a value that will display the correct decimals and ones values through the use of BCD decoders Tens and Hundreds This table begins at register address 600 to avoid paging errors in the high byte of the program counter It returns a value that will display the correct tens and hundreds values through the use of BCD decoders Version 1 Service Manual Page 20 of 63 Home Radio December 14 2001 2d Transmitter Subsystem The transmitter portion of the Home Radio is laid out on a printed circuit board The peripheral connections are power ground lines to the PIC microprocessor and RF output to th
47. lock_Hours 0 End If Version 1 Service Manual December 14 2001 Page 25 of 63 Home Radio End Sub Private Sub Timer1_Timer Increment Counter AudioPlayer Counter AudioPlayer Counter 1 If AudioPlayer Counter lt 10 Then Select Case AudioPlayer Counter Case 0 Ones Picture LoadPicture A 0 bmp Case 1 Ones Picture LoadPicture A 1 bmp Case 2 Ones Picture LoadPicture AA2 bmp Case 3 Ones Picture LoadPicture AA3 bmp Case 4 Ones Picture LoadPicture AM bmp Case 5 Ones Picture LoadPicture AA5 bmp Case 6 Ones Picture LoadPicture A 6 bmp Case 7 Ones Picture LoadPicture A 7 bmp Case 8 Ones Picture LoadPicture A 8 bmp Case 9 Ones Picture LoadPicture A 9 bmp End Select Else AudioPlayer Counter 0 Ones Picture LoadPicture A 0 bmp AudioPlayer Clock_Tens AudioPlayer Clock_Tens 1 If AudioPlayer Clock_Tens lt 6 Then Select Case AudioPlayer Clock Tens Case 0 Tens Picture LoadPicture A 0 bmp Case 1 Tens Picture LoadPicture AM bmp Case 2 Tens Picture LoadPicture A 2 bmp Case 3 Tens Picture LoadPicture A 3 bmp Case 4 Tens Picture LoadPicture A 4 bmp Case 5 Tens Picture LoadPicture A 5 bmp End Select Else AudioPlayer Clock_Tens 0 Tens Picture LoadPicture A 0 bmp AudioPlayer Clock_Minutes AudioPlayer Clock_Minutes 1 If AudioPlayer Clock_Minutes lt 10 Then Select Case AudioPlayer
48. mEventBreak break was received Case comEventFrame Framing Error Case comEventOverrun Data Lost Case comEventRxOver Receive buffer overflow Case comEventRxParity Parity Error Case comEventTxFull Transmit buffer full Case comEventDCB Unexpected error retrieving DCB Events Case comEvCD Change in the CD line Case comEvCTS Change in the CTS line Case comEvDSR Change in the DSR line Case comEvRing Change in the Ring Indicator Case comEvReceive Received RThreshold of chars tmpfreq Asc MSComm_1 Input tmpfreq2 tmpfreq tmpfreq lt 201 Then tmpfreq tmpfreq 879 10 If tmpfreq Int tmpfreq 0 Then tmpfreq tmpfreq amp 0 End If FreqText Text tmpfreq tmpfreq2 tmpfreq Else If tmpfreq lt gt 244 Then Dialog1 Hide End If Select Case tmpfreq Case 244 Test Comm testcomvar True Case 240 Set Mono MonoStereo Picture MonoStereo DisabledPicture MonoStereoMenu Caption Ch amp ange to Stereo Transmission Version 1 Service Manual December 14 2001 Page 30 of 63 Home Radio Dialog1 Caption Home Radio Mono Stereo Select Dialog1 Label1 Visible False Dialog1 Label2 Caption The transmitter is now broadcasting a Mono audio signal Dialog1 Label2 Visible True Dialog1 Show 1 Case 241 Set Stereo MonoStereo Picture MonoStereo DownPicture MonoStereoMenu Caption Ch amp ange to Mono Transmission Dialog1 Caption Home Radio Mono Stereo
49. ndreds 0 Tens 9 Hundreds 0 Tens 9 Hundreds 0 Tens 9 Hundreds 0 Tens 9 Hundreds 0 Tens 9 Hundreds 0 Tens 9 Hundreds 0 Tens 9 Hundreds 0 Tens 9 Hundreds 0 Tens 9 Hundreds 0 Tens 9 Hundreds 0 Tens 9 Hundreds 0 Tens 9 Hundreds 0 Tens 9 Hundreds 0 Tens 9 Hundreds 0 Tens 9 Hundreds 0 Tens 9 Hundreds 0 Tens 9 Hundreds 0 Tens 9 Hundreds 0 Tens 9 Hundreds 0 Tens 9 Hundreds 0 Tens 9 Hundreds 0 Tens 9 Hundreds 0 Tens 9 Hundreds 0 Tens 9 Hundreds 0 Tens 9 Hundreds 0 Tens 9 Hundreds 0 Tens 9 Service Manual December 14 2001 Page 52 of 63 Home Radio Version 1 retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw 500000011 500000011 500000011 500000011 500000011 500000011 500000011 500000011 500000011 500000011 500000011 500000011 500000011 500000011 500000011 500000011 500000011 500000011 500000011 500000011 500000011
50. ns can still be used at the user s convenience they frequency shown on the PC will be updated when the buttons are pressed Just like the frequency the Stereo Mono and Mute states of transmission can be controlled both on the box and through the PC Software Pressing and releasing the button marked Stereo on the box toggles between stereo and monaural modes of transmission In the same manner pressing and releasing the mute button toggles the mute state of transmission a dead carrier signal is outputted on and off Version 1 Service Manual Page 3 of 63 Home Radio December 14 2001 A simple audio player is packaged with the frequency control software for the user s convenience If a user does not have or wish to use WinAmp or Microsoft s Windows audio software then the Home Radio software will easily suffice It supports wav CD and mp3 playback formats which the user selects when loading a given file While the file is playing a counter is displayed that counts the number of seconds the song has been playing One of the great advantages of the Home Radio system 15 its high portability It accepts standard 12 V DC input for power the packaged AC adapter plugs into any home wall jack and the cigarette lighter permits use of the product a car As stated in the User s Manual a is not required for system operation For example a user can attach the system to a discman in the front seat of his or her car powe
51. oes or 87 9 MHz If it is at this minimum value the variable freq is set to 11001000 or 107 9 MHz otherwise freq is decremented moving the output frequency down 100 kHz Increment Frequency Within this function the up button is debounced and the frequency incremented before jumping to a transmit frequency to PC function The up button is checked to see if it is still set pressed If it is clear it s checked a second time to ensure the debounce has completed If it is not clear a small 20 millisecond delay is called Once this debounce routine has finished each bit of the frequency is checked to see if it is the maximum value freq is equal to 11001000 or 107 9 MHz If it is at this maximum value the variable freq 15 set to all zeroes or 87 9 MHz otherwise freq is incremented moving the output frequency up 100 kHz Toggle Stereo Within this function the stereo mono button is debounced and LED toggled before jumping to a transmit stereo setting to PC function The stereo mono button is checked to see if it is still set pressed If it is clear it s checked a second time to ensure the debounce has completed If it is not clear a small 20 Version 1 Service Manual Page 17 of 63 Home Radio December 14 2001 millisecond delay is called Once this debounce routine has finished the stereo LED is checked If it is set on the LED is turned off for mono transmission Otherwise it is turned on indicating a stereo
52. of the parallel network with the varactor diode and variable inductor The inductor can be adjusted with a tuning want to vary the resonant frequency of the VCO This can be used to calibrate the digital frequency settings Version 1 Service Manual Page 21 of 63 Home Radio December 14 2001 RF Output Stage The RF output is seen at pin 11 of the BH1415F and passes through a resistor network that attenuates the signal This is then passed to the Soshin GFWB6 band pass filter This assures that transmission does not exceed the desired FM band In case of Faulty operation the GFWB6 can be replaced with any band pass filters out all but 88 108 MHz The final portion of the RF output is the 2334 RF amplifier This amplifier operates in the DC 4000 MHz range and could be replaced with and any amplifier that accepts 88 108 MHz Voltage Test Point The voltage between the two 3 3K resistors is the control voltage for the VCO This voltage can be observed to determine if the phase lock loop system PLL is operating properly When the PLL is not locked occurs on power up or when a new frequency has been selected the test voltage should either raise from a low voltage to 5 or lower from 5 to close to zero volts This is when PLL is searching for the frequency to lock on Once the PLL finds the correct frequency the control voltage should stabilize and no longer vary Version 1 Service Manual Page 22 of 63 Home Radio 3a PC Code
53. on still pressed Yes go back Wait for debounce Delay 20 msecs the stereo mono button still pressed Yes go back again Skip small loop if Debug is defined Increment the delay count lf low byte w is not equal to zero then loop Else short loop ls mute already selected No mute transmission Yes turn mute LED off Turn mute LED on Service Manual December 14 2001 Page 45 of 63 Home Radio Display Freq dispf movlw movwf movfw call movwf movlw movwf movfw call movwf call goto Transmit Freq trans bsf bsf bcf movfw movwf bsf trans2 btfss goto bcf call bsf bcf bcf goto txst bsf bsf bcf btfss goto txst1 movlw goto txst2 movlw txst3 movwf bsf txst4 btfss goto bef Version 1 HIGH decone PCLATH freq decone PORTD HIGH tenhun PCLATH freq tenhun PORTE wdata main STATUS 5 TXSTA 5 STATUS 5 freq TXREG STATUS 5 TXSTA 1 trans2 STATUS 5 delay STATUS 5 TXSTA 5 STATUS 5 dispf STATUS 5 TXSTA 5 STATUS 5 SterL txst2 OxF1 txst3 OxFO TXREG STATUS 5 TXSTA 1 txst4 STATUS 5 Set counter to correct table address table for decimals and ones display Display decimals and ones values Set counter to correct table address table for tens and hundreds display Store frequency in eeprom not used Transmit new frequency to PC Regi
54. r up the system with the cigarette lighter adapter and listen to compact discs on the car s FM radio Version 1 Service Manual Page 4 of 63 Home Radio December 14 2001 2a PC Software The code described in this section is listed in section 3d of this Service Manual The following steps through the code function by function providing explicit detail that cannot be obtained from the comments in the code Splash Screen Interface The splash screen serves no purpose other than for aesthetics When the Home Radio GUI is loaded it appears on the screen after 1 5 seconds or any key press it disappears and the main window appears This is accomplished through the following functions 25 Form_KeyPress KeyAscii As Integer closes the Splash Screen Interface window when key is pressed Form_Load sets up the version label text box Frame 1_Click closes the splash screen when the mouse clicks the within the frame Timerl Timer after 1500 milliseconds it closes the Splash Screen Interface window Main Interface All of the functionality that the GUI provides be accessed from this window It is both menu and command button driven The following is a detailed list of the functions provided by the main form Version 1 Form Load loads the Splash Screen Interface window selects communication port 1 sets port one for 2400 baud no parity 8 data and 1 stop bit sets the communic
55. re LoadPicture AA0 bmp End If Version 1 Service Manual December 14 2001 Page 24 of 63 Home Radio Timer1 Enabled True End If Else 1 Then MMControl1 Command Play If AudioPlayer Counter 0 Then Hours Picture LoadPicture A 0 omp Minutes Picture LoadPicture A 0 bmp Tens Picture LoadPicture A 0 omp Ones Picture LoadPicture A 0 bmp End If Timer1 Enabled True End If End If End Sub Private Sub Prev_Click Hours Picture LoadPicture AA0 bmp Minutes Picture LoadPicture A 0 omp Tens Picture LoadPicture A 0 bmp Ones Picture LoadPicture A 0 bmp AudioPlayer Counter 0 AudioPlayer Clock_Tens 0 AudioPlayer Clock_Minutes 0 AudioPlayer Clock_Hours 0 sure device has been selected If DeviceType 1 Then AudioSelection Show 1 End If Select Correct Device If AudioPlayer DeviceType 0 Then Do Nothing Else MMControl1 Command Prev End If End Sub Private Sub Stop Click Timer1 Enabled False sure device has been selected If DeviceType 1 Then AudioSelection Show 1 End If Select Correct Device AudioPlayer DeviceType 0 Then AP Stop AudioPlayer Counter 0 AudioPlayer Clock_Tens 0 AudioPlayer Clock_Minutes 0 AudioPlayer Clock_Hours 0 Else MMControl1 Command Stop MMControl1 Command Prev AudioPlayer Counter 0 AudioPlayer Clock_Tens 0 AudioPlayer Clock_Minutes 0 AudioPlayer C
56. requency is not correct Check to make sure that the serial data is being sent properly Refer to the BH1415F data sheet for timing diagrams and specifications relating to the serial data Verify that the phase lock loop system is working by measuring the control voltage of the VCO This is between the two 3 3K resistors shown in Figure 5 in section 3d This voltage should lower and raise between 0 5 volts searching for the correct frequency It should then stabilize when the frequency is found and the frequency becomes stable Verify that the connections to the RF output are correct and that there are no shorts to ground Verify that the oscillator connected to pins 13 and 14 of the BH1415F is actually oscillating If not replace the oscillator Audio is distorted Measure the composite output at pin 5 of the BH1415F to verify that the audio signal is not being clipped by the audio limiter built into the BH1415F If it is being clipped adjust the 100K potentiometer connected to the right and left channels such that the output of pin 5 is no longer clipped Audio is being played but no signal is heard Verify that the mute pin 18 of the BH1415F is low Check the composite signal output pin 5 to verify that audio is propagating through the chip If there is no AC signal try adjusting the right and left channel potentiometers It is possible that they are set such that all the audio is being attenuated Verify that the audio source is a
57. ry blank on the Set Frequency Interface Window closes the Error Interface window User Help Interface The User Help Interface is used to act as a quick reference guide to the novice user of the Home Radio system It has a list of assumed typical questions that the user may have By clicking on the question the user is given a brief answer The user can view the different questions and answers and many times as necessary without reopening the window The functions listed below are used to accomplish these tasks 2 Form Load initializes variables used to keep track of the two display modes Version 1 Service Manual Page 7 of 63 Home Radio December 14 2001 2 Command1_Click changes the display from an answer back to the main list of questions retains the last answer displayed 2 Command2_Click changes the display from the main list of questions to the last answer displayed Command3 Click closes the User Help Interface and returns control to the Main Interface window Listl Click according to the question clicked on by the user displays the answer Communications Test Interface The Communications Test Interface is used to carry out the communications test between the GUI and the transmitter signal is sent out serially by the GUI The transmitter is then given 3000 milliseconds to respond If it does not by the given time an alert dialog appears and reports the test failed Otherwise an alert
58. s 0 Tens 9 Hundreds 0 Tens 9 Hundreds 0 Tens 9 Hundreds 0 Tens 9 Hundreds 0 Tens 9 Hundreds 1 Tens 0 Hundreds 1 Tens 0 Hundreds 1 Tens 0 Hundreds 1 Tens 0 Hundreds 1 Tens 0 Hundreds 1 Tens 0 Hundreds 1 Tens 0 Hundreds 1 Tens 0 Hundreds 1 Tens 0 Hundreds 1 Tens 0 Hundreds 1 Tens 0 Hundreds 1 Tens 0 Hundreds 1 Tens 0 Hundreds 1 Tens 0 Hundreds 1 Tens 0 Hundreds 1 Tens 0 Hundreds 1 Tens 0 Hundreds 1 Tens 0 Hundreds 1 Tens 0 Hundreds 1 Tens 0 Hundreds 1 Tens 0 Hundreds 1 Tens 0 Hundreds 1 Tens 0 Hundreds 1 Tens 0 Hundreds 1 Tens 0 Hundreds 1 Tens 0 Hundreds 1 Tens 0 Hundreds 1 Tens 0 Hundreds 1 Tens 0 Service Manual December 14 2001 Page 53 of 63 Home Radio Version 1 retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw retlw end b 00000100 b 00000100 b 00000100 b 00000100 b 00000100 b 00000100 b 00000100 b 00000100 b 00000100 b 00000100 b 00000100 b 00000100 b 00000100 b 00000100 b 00000100 b 00000100
59. s both hardware and software aspects of the system As described in the user s manual Home Radio is designed to transmit any stereo or audio signal inputted to the device through its RCA compatible jack located on the rear side of the system box Any output frequency between 87 9 and 107 9 MHz can be selected in 100 kHz increments Since all commercial stations broadcast on the odd tenths example 97 9 or 102 3 we have included the option of transmitting on the even tenths example 88 8 doubling the number of output frequency levels This permits the user to better use small areas of open bandwidth The current output frequency is displayed on the four seven segment displays on the front of the transmitter box The frequency can be controlled two ways on the box and through the use of a PC with the packaged software The transmitter box has buttons labeled Up and Down These buttons as expected raise and lower the frequency By pressing and releasing one of these buttons the frequency is either incremented or decremented 100 kHz The second method of controlling the frequency is with the packaged Home Radio software which operates on any Windows platform The PC will be connected to the transmitter box through the serial cable provided with the system The PC and transmitter communicated via the RS 232 standard of operation One convenient aspect of the system is that when the PC is attached the box butto
60. s the Set Frequency Interface window UpIncrementButton_Click adds 1 kHz to the current broadcast frequency if 107 9 changes the value to 87 9 calls the private sub function TxFreq DnlincrementButton Click subtracts 1 kHz from the current broadcast frequency if 87 9 changes the value to 107 9 calls the private sub function TxFreq MuteButton_Click sends a message to transmitter to change mode of operation changes the display on the tool bar to fit the current state of the transmitter changes the description of the function on the drop down menus to fit the current state of the transmitter loads the Dialog Interface window with the appropriate message MonoStereo Click sends a message to transmitter to change mode of operation changes the display on the tool bar to fit the current state of the transmitter changes the description of the function on the drop down menus to fit the current state of the transmitter loads the Dialog Interface window with the appropriate message TestComm Click sends a message to the transmitter signaling a communications test loads the Communications Test Interface window HelpButton_Click loads the User Help Interface window MSComm1_OnComm receives input from the communications port control dissects input to determine whether to change frequency or change mode of operation 1 mute the Service Manual Page 6 of 63 Home Radio December 14 2001 transmitter
61. ster Page 1 Enable transmission Register Page 0 Load frequency for transmission Send the frequency Register Page 1 Wait until transmit buffer is empty Register Page 0 Register Page 1 Disable transmission Register Page 0 Register Page 1 Enable transmission Register Page 0 15 stereo on Yes send F1 send FO Send the state Register Page 1 Wait until transmit buffer is empty Register Page 0 Service Manual December 14 2001 Page 46 of 63 Home Radio call bsf bcf bcf goto txmut bsf bsf bcf btfss goto txmut1 movlw goto txmut2 txmut3 bsf txmut4 btfss goto bcf call bsf bcf bcf goto delay movlw movwf delay2 2 goto return delay STATUS 5 TXSTA 5 STATUS 5 main STATUS 5 TXSTA 5 STATUS 5 MuteL txmut2 OxF2 txmut3 OxF3 TXREG STATUS 5 TXSTA 1 txmut4 STATUS 5 delay STATUS 5 TXSTA 5 STATUS 5 main 0FFh count count delay2 This feature is not currently in use rdata bsf bcf movf movwf bsf bcf Version 1 STATUS STATUS RPO addr w EEADR STATUS RPO EECON1 EEPGD Register Page 1 Disable transmission Register Page 0 Register Page 1 Enable transmission Register Page 0 16 mute on Yes send F2 No send F3 Send the state Register Page 1 until transmit buffer is empty Register Page 0
62. ual December 14 2001 Page 28 of 63 Home Radio End Sub Private Sub ChangeFreqButton_Click Form2 Show 1 End Sub Private Sub Commandt1 Click Dialog Hide MSComm1 Output Chr 244 Dialog Show 1 End Sub Private Sub ContentsCommand Click helpwin Show 1 End Sub Private Sub Command2_Click Form4 Show 1 End Sub Private Sub DnlncrementButton Click If FreqText Text gt 87 9 Then FreqText Text FreqText Text 0 1 If FreqText Text Int FreqText Text 0 Then Tmp FreqText Text amp 0 Tmp End If Else FreqText Text 107 9 End If TxFreq End Sub Private Sub ExitCommand_Click Unload Form1 End Sub Private Sub Form_Load testcomvar False frmSplash Show 1 Use COM1 MSComm1 CommPort 1 2400 baud no parity 8 data and 1 stop bit MSComm1 Settings 2400 N 8 1 the control to read entire buffer when Input 1 used MSComm1 InputLen 1 MSComm1 RThreshold 1 the port MSComm1 PortOpen True Send the attention command to the modem End Sub Private Sub MonoStereo_Click MonoStereo Picture MonoStereo DisabledPicture Then MonoStereo Picture MonoStereo DownPicture MonoStereoMenu Caption Ch amp ange to Mono Transmission Dialog1 Caption Home Radio Mono Stereo Select Dialog1 Label1 Visible False Dialog1 Label2 Caption The transmitter is now broadcasting a Stereo audio signal Dialog1 Label2
63. us one and the returned value is moved to port E displaying the correct tens and hundreds digits The code now returns to main Transmit Frequency The data stored in the variable freq is sent to the PC through this function which then jumps to a display routine Transmission is enabled and the freq is loaded into the transmit register A loop then repeatedly checks the transmit buffer to see if it is empty if it is not a small delay routine is called Once Version 1 Service Manual Page 18 of 63 Home Radio December 14 2001 the buffer is emptied and transmission is finished transmission is disabled The program then jumps to the aforementioned display code Transmit Stereo Setting This function sends the stereo mono state serially to the PC Transmission is enabled and the stereo LED is checked If it is on hexadecimal F1 the opcode for set stereo is loaded to the transmit register Otherwise hexadecimal FO the opcode for mono transmission is loaded to the transmit buffer As in all of the other serial transmission functions a loop repeatedly checks the transmit buffer A delay is called until the buffer is empty at which point the transmission is disabled since it is finished We then jump back to the main code Transmit Mute Setting This function sends the mute state serially to the PC Transmission is enabled and the mute LED is checked If it is on hexadecimal F2 the opcode for set mute is loaded to the transm
64. ut Chr freq End Sub Set Frequency Form Code Private Sub cmdCancel Click Me Hide End Sub Private Sub cmdOK Click If SetFreqText Text gt A And SetFreqText Text lt z Then Form3 Show 1 Elself SetFreqText Text Then Form3 Show 1 Else Version 1 Service Manual December 14 2001 Page 32 of 63 Home Radio If SetFreqText Text gt 87 9 And SetFreqText Text lt 107 9 Then If SetFreqText Text Int SetFreqText Text 0 Then SetFreqText Text SetFreqText Text amp 0 End If Form1 FreqText Text SetFreqText Text Else Form3 Show 1 End If End If Form1 TxFreq Me Hide End Sub CO Error Form Code Private Sub cmdOK_Click Form2 SetFreqText Text Unload Form3 Unload Form2 Form2 Show 1 End Sub CO Help Form Window Public fwd As Integer Public textwindow As Integer Private Sub Command1 Click If textwindow 0 Then List1 Visible True Select Case textwindow Case 1 Text1 Visible False fwd 1 Case 2 Text2 Visible False fwd 2 Case 3 Text3 Visible False fwd 3 Case 4 Text4 Visible False fwd 4 Case 5 Text5 Visible False fwd 5 Case 7 Text6 Visible False fwd 7 Case 8 Text7 Visible False fwd 8 Case 9 Text8 Visible False fwd 9 End Select textwindow 0 End If End Sub Private Sub Command2_Click If fwd gt 0 Then List1 Visible False Select Case fwd Case 1 Text
65. yer Next Enabled True Version 1 Service Manual December 14 2001 Page 27 of 63 Home Radio Case 1 AudioPlayer DeviceType 0 AudioPlayer Open Enabled True AudioPlayer Prev Enabled False AudioPlayer Next Enabled False Case 2 AudioPlayer DeviceType 2 AudioPlayer Open Enabled True AudioPlayer Prev Enabled False AudioPlayer Next Enabled False End Select Me Hide End Sub Test Communication Code Private Sub OKButton Click Unload Dialog If Form1 testcomvar False Then Form1 MSComm1 Output Chr 244 Dialog Show 1 Else Form1 testcomvar False End End Sub Private Sub Timer1_Timer Form1 testcomvar True Then TestBar Value 100 CancelButton Enabled False TestBar Visible False Label1 Visible False Label2 Visible False Label4 Visible True OKButton Enabled True Else Label1 Visible True TestBar Visible True If TestBar Value lt 100 Then TestBar Value TestBar Value 10 Elself TestBar Value 100 Then OKButton Enabled True Label1 Visible False TestBar Visible False Label2 Visible True Image1 Visible False Image2 Visible True End If End If End Sub CO Mute Mono Stereo Form Code Private Sub Timer Timer If Form1 tmpfreq2 lt gt 244 Then Me Hide End If End Sub CO Window Code Public testcomvar As Boolean Public tmpfreq2 As Variant Private Sub AboutCommand_Click AboutForm Show 1 Version 1 Service Man

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