ELFDRV1 stepper driver user manual
Contents
1. ELFSHL1 shield VMOT bypass capacitor is already fitted Supply connectors VMOT Motor driver voltage 8 V to 35 V pin GND ground reference pin 5V logic supply for the driver Warning This driver board uses low ESR ceramic capacitors which makes it susceptible to LC voltage spikes At times these spikes can well exceed the 35 V maximum voltage rating for the DRV8818 and can permanently damage the driver even when the motor supply voltage is as low as 12 V One way to protect the driver from such LC voltage spikes is to place a large gt 47uF electrolytic cap on the 12V power rail ELFDRV1 stepper driver electroFUN LID 8 Motor Connections ELFDRV1 stepper driver motor connections 3 bipolar motor com 4 unipolar motor O Q B BCOM B bipolar motor are connected directly to the driver Ensure that phases coincide unipolar motors with 6 and 8 wires can be connected to the driver as if they were bipolar motors The center tap A COM can be connected instead of A to reduce the inductance you will be able to get higher step orders while sacrificing torque Warning Connecting or disconnecting a stepper motor while the driver is powered can destroy the driver in general rewiring anything while it is powered is asking for trouble ELFDRV1 stepper driver electroFUN LID 9 Driver Configuration micro stepping Most stepper motors have a step size of 1 8 or 200 steps per revolution This is the2. step resolution that would be achieved when the driver is configured in full step mode This micro stepping driver allows for higher step resolutions This is managed internally by the DRV8818 by energizing the coils with intermediate current levels Step resolution for 200 steps per revolution motor Full step 200 steps per revolution 1 89 1 2 400 steps per revolution 0 9 1 4 800 steps per revolution 0 459 1 8 1600 steps per revolution 0 225 micro stepping jumper configuration bottom board view micro stepping configuration The step size can be configured using the built in jumpers which can be found at the back of the board The board is contigured in 1 8 of a step with jumpers on uSTEP configured to USMO 1 and USM1 1 by default ELFDRV1 stepper driver electroFUN LTD 10 Current limiting To achieve higher step rates the motor supply should be much higher than would be permissible without active current limiting current chopping For example most stepper motor specify what their maximum current ratings and coil resistence is as opposed to their rated voltage This is because they specify the current rating at which the motor coils are rated If we consider a typical 2A stepper motor with a 2 50 coil resistance it would indicate a maximum motor supply of 5 V However if we want to achieve higher step rates we would need to energize the coils quicker by simply raising the voltage to 12 V for exampl
3. stepper driver electroFUN LID 14 HARDWARE Main hardware related section with the board schematics board layout and components mechanical drawings with board dimensions Original files can be download from www electrofunLTD com ELFDRV1 stepper driver electroF UN LID 15 Schematic T T heeys jP2AES LOU s y A8QWUNN 1U9WN20 Hansa HIddALS JSAtAGJA010 Uaddais FT pa R 25 Q s35U30I DJ0 5UOUNOISANE aD i sid m ve nay asuaD17 BS SYNP SJOUG UOTINGLAW SUOWIOY 340834 SUL apun paseas O17 NNJ04 29313 AE WS OD tuama vedo r JN 04 U03 dans ZATEN Z15306 oO a JNET HENZE B TJ 23 A0 Ad AZA9 Gd 37 E 6269 93Nd SXEINIOd LS31 SXELNIOd LS3L IN 6 O AST 0O4UDD Aoddss eseyd 4010W TANGAIA A4 At4q Aeddars 16 ELFDRV1 stepper driver electroF UN LID Board Layout Components Part Value C1 C2 C3 0 22uF C4 C5 1nF C6 C7 C10 O 1uF C8 C9 10uF CUR S 10K D1 D8 diode IC1 DRV8818 JP 1 IN JP2 MOT L1 L3 Green L2 L4 Req R1 R2 0 1R R3 R5 RY 22K R4 2K2 ELFDRV1 stepper driver board layout 7 Sar In il I AOUT1 AOUT2 BOUT1 10 R C5 RS C4 C6 BORO sl Oar 42UG6ND BU EN DIR STP BOUT2 IL 100000 To do o Package C0805 C0805 C0805 A 3216 18R TRIMPOT BOURNS3MM SOD 128 HTSSOP28PWP MOLEX 1X6 MOLEX 1X4 CHIPLED 0805 CHIPLED 0805 R1210 MO805 MO805 ELFDRV1 stepper driver elect
4. ation 4 Driver Control Sy Thermal Considerations Using the driver The driver has been designed for minimum configuration and external control from an MCU just a simple step command HIGH LOW pulse on the STP pin and a direction pin DIR HIGH or LOW to turn the motor clockwise or anti clockwise A simple EN pin active low will enable or disable the ELFDRV1 output drivers The driver comes pre configured to work in mixed decay mode giving a more flexible configuration for its current recirculation The driver is configured in 1 8 step mode and can easily be reconfigured using 2 solder jumpers Minimal wiring diagram for connecting a microcontroller to the ELFDRV1 stepper motor driver carrier ELFDRV1 stepper driver electroFUN LTD 6 ELFDRV1 stepper driver supply rails supply rails MCU IO control lines GPIOI GPIO2 GPIO3 supply rails VMOT 8 V to 35 V marked as 12 V on the PCB Vcc 3 V to 5 5 V marked as 5 V on the PCB GND common ground between supply rails MCU IO control lines EN active low DIR HIGH or LOW CW ACW STP HIGH LOW pulse ELFDRV1 stepper driver electroFUN LID Power connections The driver requires a logic supply voltage 3 V 5 5 V to be connected across the Vcc and GND pins and a motor supply voltage of 8 V 35 V to be connected across VMOT and GND VMOT supply should have appropriate decoupling capacitors close to the board if using the CNC stepper mother board
5. e However we should be actively limiting the current to be under 2 A to prevent damage to the motor s coils The ELFDRV1 is based on II s DRV8818 which supports such active current limiting It is configured using the onboard trimmer potentiometer Current setting potentiometer P1 test point Current Adjust Pot The easiest way to configure the output current per phase is to power the board with a 5V supply or the voltage you are going to use on your project using the 5V and GND pins Measure the voltage on test point P1 please refer to image and adjust the potentiometer The coil current is calculated as follow I C V P1 0 8 ELFDRV1 stepper driver electroF UN LID 11 For example to achieve a 1A coil current you should adjust the potentiometer till you read 0 8 V on test point P1 By default the board is configured to deliver 1 A per phase trimmed using 5V on Vcc Warning do not exceed to 2 5 A maximum current rating of the board It will get very hot and continuos usage beyond the 2 5A rating will cause permanent damage to the driver This is the same as saying never exceed V P1 2 V when the board is in use in your project Decay mode configuration The decay mode can be configured by using a simple solder jumper By detault solder jumper completely open it is contigured in mixed decay mode In mixed decay mode the driver automatically selects the best coil discharge mechanism at a particular ins
6. electroF UN LID ZLT Li O dn O Bi Q ELFDRV1 Stepper Driver Rev 1 0 ELFDRV1 stepper driver electroF UN LTD 1 FUN FUN LID 2012 electroF UN LTD Stepper Driver ELFDRV1 by F Malpartida is licensed under a Creative Commons Attribution ShareAlike 3 0 Unported License Based on a work at http www electrofunltd com ELFDRV1 stepper driver electroF UN LTD 2 BRIEF The ELFDRV1 stepper motor driver carrier Is an easy to use performant bipolar micro stepping motor driver The driver features adjustable current limiting over current protection and 4 different configurable micro step resolutions It operates from 8 V 35 V and can deliver up to 2 5 per coil Fitted with external diodes to improve the over all thermal dissipation of the driver Description The ELFDRV1 is a compact carrier board or breakout board for TIs DRV8818 Micro stepping Driver with Indexer and over current protection for driving stepper motors This stepper driver lets you control one bipolar stepper motor up to 2 5 per winding Please refer to the heat dissipation section of this manual for optimum performance ELFDRV1 stepper driver electroFUN LID 3 Features FEATURES Just two control interface pins for step and direction One interface pin to enable the driver Four different step resolutions jumper contigurable full step 1 2 1 4 Wis Adjustable current control lets you set the maximum current ou
7. roF UN LID 17 Board Dimensions ELFDRV1 stepper driver board dimensions N arn fia Rat est Ast C4 Cat SCHORS EEE I i SCHE pat board dimensions ELFDRV1 stepper driver electroF UN LID 18 Assembled stepper driver on ELFSHL1 stepper shield driven by the vinciDuino ELFDRV1 stepper driver electroF UN LID 19
8. tant in time slow or fast decay This is what we call automatic discharge selection If you are doing micro stepping mixed decay mode is the only way to go Decay mode configuration Fast decay If you don t know what decay mode is please leave the default configuration ELFDRV1 stepper driver electroFUN LTD 12 Driver Control Each pulse to the STP input corresponds to one micro step of the stepper motor in the direction selected by the DIR pin These pins need to be actively driven and should not be left floating Should you wish to only have the motor turning in only one direction you can tie the DIR pin to Vcc or GND Driver board control pins Direction pin Step pin You will also need to control the EN pin of the board to activate the output drivers of the DRV8818 The pulse high low cycle on the STP pin should have a duration of at least 1us ELFDRV1 stepper driver electroFUN LTD 13 Thermal Considerations The DRV8818 ASIC and hence the ELFDRV1 driver has a maximum current rating of 2 5 A per phase The actual current it can deliver depends very much on how well you cool the DRV8818 Care has been taken when designing the circuit board to allow regular operation up to 1 5 A per phase However the actual current you can deliver the motor depends on how well you can keep the DRV8811 cool We have achieved 2 A sustained operation with a heat sink and 2 5 A with a heat sink and forced air cooling ELFDRV1
9. tput with a potentiometer allowing you to use a wide range of supply voltages well above your stepper motors rated voltage This will protect you motor and will enable you to achieve higher step rates selectable decay modes using built in jumpers slow decay fast decay or mixed decay Mixed decay provides a more intelligent chopping control by selecting the correct current decay mode automatically board default Board has been designed for vertical mounting for optimum cooling under high current needs In addition is occupies less space on your final project The ELFDRV1 ships with all SMD components soldered on board tested and with a set of header pins for you to solder We also have an Arduino UNO Rev 3 and Leonardo or vinciDuino daughter board shield that can host up to 3 ELFDRV1s making it an ideal and compact solution for driving a CNC machine Please refer to the PLP il ELFDRV1 stepper driver electroF UN LTD Specifications Dimensions Size 43mm x 33 mm Weight 69 General specifications Motor driver Logic operating voltage range Motor driver operating voltage range Continuous output current per phase Min step pulse duration PCB ELFDRV1 stepper driver electroF UN LID DRV8818 SV 55V 8 V 35 V up to 2 5 lus FR4 35um copper white solder resist 1 6 mm USER GUIDE CONFIGURATION AND USAGE 1 Using the Driver 2 Power pin connection and wiring 3 Driver Configur
Download Pdf Manuals
Related Search