Why are mounting holes either non-existent, or just poorly thought out? I see nifty boards that would be nice to grab, but the majority of the time there is no thought put into mounting. I wish more hobby designers thought about mounting holes more like computer motherboard manufacturers. For instance, the holes have a good clearance from the edge of the PCB, other components, and indicating marks. There is enough clearance for the head of a screw and probably a washer without any worry of smashing a component, the thin PCB edge or covering part of the silk screen.

Maybe I'm missing something but those current sensing resistors appear to be a bit undersized. At a continuous 2A drive the power dissipated by each pair of 1 ohm resistors is (2A ^2) * 0.5 ohms = 2W. Each resistor should be rated for at least 1 watt.
I think the sensing resistors are above the Atmega and they appear to be 0603 packages. AFAIK, 0603's tend to dissipate between 0.1W to 0.25W.
Assuming a 0.25W resistor the maximum current drive is sqrt(0.25W / 0.5 ohms) = continuous 0.71A max per channel. Or about a 35% duty cycle at 2A.

It would be awesome if the next version included inputs for two quadrature encoders, to allow for closed loop speed control and position reporting.

There seem to be a number of questions here about command format. Of course you first want to be sure your link is configured for 1152000 bps. I'm sending my commands to the Motor Controller using the Software Serial library for the Arduino UNO board and all are coded similar to this: ss.print("1R8\r"); . Works fine.

I did find that it is a good idea to send the FIRST command in the sketch TWICE. Otherwise it was not always effective.

   How come these comments are all so old?

I have been designing something similar except is uses I2C to control the motors and uses a ATmega328 so I can just write arduino code to the other difference is I use 4 gpio pins to allow for i2C addressing. I would rather use a sparkfun part but serial is expensive I2C would be my choice as I can use two pins and send to multiple motor controllers and devices. any chance you guys might make a i2C version wouldn't take much just a update to the firmware and provide the ability to update an address byte if you have some eeprom space left. I just don't have the right skills to write that code, compile and flash the 168 chip. i see in the schematic it is already wired up with the i2c pins.

i think there is a problem with the firmware, the compiler says this:

Arduino: 1.5.6-r2 (Windows 7), Board: "Arduino Uno"

In file included from sketch_jul13a.ino:8: main.h:52: error: expected primary-expression before '.' token main.h:52: error: expected primary-expression before '.' token main.h:52: error: expected primary-expression before '.' token main.h:52: error: expected primary-expression before '.' token In file included from C:\Program Files (x86)\Arduino\hardware\arduino\avr\cores\arduino/Arduino.h:245, from sketch_jul13a.ino:13: C:\Program Files (x86)\Arduino\hardware\arduino\avr\variants\standard/pins_arduino.h:41: error: expected unqualified-id before numeric constant C:\Program Files (x86)\Arduino\hardware\arduino\avr\variants\standard/pins_arduino.h:42: error: expected unqualified-id before numeric constant C:\Program Files (x86)\Arduino\hardware\arduino\avr\variants\standard/pins_arduino.h:43: error: expected unqualified-id before numeric constant

This report would have more information with "Show verbose output during compilation" enabled in File > Preferences.

Is the firmware posted current? The makefile says the device is atmega168, but it is a atmega328(p?). The more troubling issue regards the ADC setup code. Let me know if I am reading this wrong. In ioinit(), you set the ADATE bit in ADCSRA, but do not set ADTS bits in ADCSRB to select the triggering mode. Why are you autotriggering when you need to start a new conversion after the current conversion has been read in the ADC ISR?

Hi to all, I bought a pair of this board, conneted the first to my rover and send command from terminal and it works. After try with a Python program that sends the same commands and the card goes up in smoke, I looked at the firmware and there are so many controls that can not see that a wrong command may have triggered the problem. Now I find myself with a broken board, what can I do?

One motor is spinning slower than the other. Is this the driver or the motor? They both have a speed constant of 5.

I think this motor driver is great. I am using this on the multi-chassis tank version with a big, salvaged heat sink. I stalled the motor by holding it and the overcurrent light never came on. It also kept going very strong after the stall.

Would the serial command look like this? mySerial.print('1' 'f' '2' '/r')

What and how can the unused atmega pins be used for?

Is flyback protection built in?

Ok first off has any one used this with something other than an ardrino? I'm using a MSP430FR5739, and the baud rate is definitly set for 115200 (tested with another serial device) and used an oscilloscope to test the tx pin of my mico to make sure it actually is sending the data, which it is. So for sure my micro is good BUT the motor driver does absolutly nothing, doesn't send anything back on the Tx line, the stat lights do nothing. the most i get is a red indicator light when i supply power. The only things i can say i notice are the tx pin of my micro starts high, then goes to 0 for a start bit, continues on with all the data, goes high for a stop bit, and stays high after. The board doesn't go 0-5V it goes 0-3.6V which according to TTL logic anything past 2.7V's is a high so that should still work. And that latter is there is no info in the data sheet about MSB or LSB frist. And if any ones says i need to flash the board, then it's simply going back cause i'm not also buying an ardrino to flash a board taht should come ready to go.

Hey gents, new here. Got this thing to work without any problems.
Question: In the User's Guide it says

"The speed is entered with an ascii number anywhere in the range of 0 and 9. If '0' is ued for the speed, the motor will be stopped (and the direction indicator doesn't matter). If '9' is entered for the speed value, the motor will run at full speed. If any other speed value is used, the motor will receive a pulse width modulation signal to control the speed."

Any one know how I can specify speed value outside of 0-9? Or if it's even possible? Thank you much.

This little board worked a charm when using a 7.4v LiPo. Be careful when supplying more than 12 volts. When I supplied 14.8v the 47uF capacitor (C8) exploded. It's probably a max 16v capacitor. Also notice that the L298 on the board has no heat sink. It gets smoking hot when driving an RC car motor. I confess removing the overcurrent protection from the firmware. My conclusion, great little board. My suggestions to SF for a new version of the board are obvious, replace the capacitor and use a L298 with heatsink.

Hi there, I bought this motor from you and it has 4-wires which indicates that it is a Bipolar stepper motor. http://www.sparkfun.com/products/10848

I have also purchased this motor driver. How do I use this driver to drive the 4-wire bipolar motor? Thanks

Hello,

Has ANYONE got this thing to work?? I have copy and pasted some of the code provided here in this forum, but the compiler gives me an error signal unless I change the coding from:

Serial.write(‘1’); // to control motor 1

to:

Serial.write('1'); // to control motor 1

It's the apostrophe on each side of the 1 that has to be changed. I don't even know what to call the original symbols. Anyway, I have everything downloaded, but nothing happens. No motor, no voltage out, zip. I have two of these boards and nothing seems to work. Help!

how i upload the firmware to this, because i only have the main.c and .h files and arduino compiler is asking for pde files??

can some one pls give me an example code for using with arduino?

is there any reason I couldn't use an ISP to program this with the Arduin IDE?

Or even load a boot loader (using an ISP), break off the reset pin, and program it with a serial port just like any other Arduino?

This board is exactly what I am looking for but I have a codebase in Arduino. I don't see any reason to move it all over to WinAVR If I could just turn this little guy into an Arduino.

I need help!!!!

I just noticed in the serial monitor that if you code the Serial.print('\r'); then this will NOT print. It will print the / but not \ which seems to be a common post as a mistake by the user guide. Can someone help me with this? I am using an Arduino Mini Pro 5V w/ ATMega328. Here is my code. I did not comment it out.

void setup() { Serial.begin(115200); //set serial to 115200 baud rate } void loop() {

Serial.write('1'); Serial.write('f'); Serial.write('5'); Serial.write("\r"); Serial.println(); digitalWrite(13, HIGH); delay(2000); Serial.print('1'); Serial.print('r'); Serial.print('5'); Serial.print("\r"); Serial.println(); digitalWrite(13, LOW); delay(2000);

}

Is this, serial controlled motor driver, compatible with arduino mega 2560?

Can this measure motor speed and return it via Serial?

Hi all,
I am trying to setup this board with netduino but no luck so far!
Based on user's guide it should be simple.
I've wired VCC/GND to the Vin/GND at netduino board (vin is 6V dc) TX/RX to D0/D1 (rx/tx) on netduino.
The code is something like this:
SerialPort com1 = new SerialPort("COM1", 115200, Parity.None, 8, StopBits.One);
com1.Open();
byte[] cmd = encoding.GetBytes("1f5\r");
com1.Write(cmd, 0, cmd.Length);
The should be ok, since I am using same for other serial components and its working fine.
There is no any activity on M1(+/-). always 0V.
Did anybody manage to run this board? Do I need to program board first or its already pre-loaded with firmware?
Thx,Ian

I have 3 of these. I think I'm doing everything right but nothing works. This is my arduino code:
#include
NewSoftSerial mcser = NewSoftSerial(2, 3);
void setup(){
mcser.begin(115200);
delay(1000);
}
void loop(){
mcser.print('1f5\r'); // to control motor 1
delay(2000);
}

as a query, could the voltage reset issue be solved by removing or cutting the output of the 5v reg, then tying the arduino 5v onto the motor driver board 5v "out" (making it an input for 5 v from an external regulated supply). Then running the arduino from a separate power supply to the vcc of the motor controller, eg a 9v battery wired to the arduino Vin.
cheers

I got mine to work after flashing the most current firmware. They should be updating them now before shipping, but I am not sure.

Hi.
I am trying to make Ip Cam Rover somewhat like this ( http://letsmakerobots.com/node/22674 )
instead of using arduino, I used Serial Controlled Motor Driver.
there is foscam CGI command, comm_write.cgi which explained on this manual.
https://docs.google.com/uc?export=download&id=0B-yhhBvC0DSlNWExZDU0NTQtMDlmZi00YzkzLWFkNDAtMGU4MTA1MDg2YjMz
I am using this command to control my rover.
http://192.168.0.196/comm_write.cgi?port=0&baud=4098&bytes=4&data=1f4/r
but somehow it is not working.
I'd like to know what I am doing wrong.
Thanks

Hi. I just got a few of these for a project along with some motors, but I can't get it to work at all. I have everything wired up to an arduino and I have tried tx/rx and NewSoftSerial but I can not get a twitch or signal. I think it is a problem with communications because I don't seem to be sending anything or getting anything back. I have tried sending each character individually and sending them together but no luck. Anyone have any ideas?

For the life of me I can't get this thing to work. I reloaded the firmware since it would just turn on and both stat LED's would be lit. No matter what I do it won't turn the motors on.
I have it at 115200 and nothing. I get a ready on startup too. Whenever I send a command I get the command echoed back on the serial.
Any ideas?

I saw some comments about the sense resistors here...
What are you using as sense resistors?
My applicatioon is sensitive to their characteristics.
In particular their stability at different tempretures.
And the maximum load I should expose them to.
I can work within most limits - but do need to understand them first.
Background:
I want to use the sensed current to infer the load on the motor - and hence the work being done..
I am trimming sails on a model boat, so the tension on the rope is a good control input:).
Regards,
D

As logictechs suggests, it's not too tricky to upload new firmware via an Arduino (http://robotics-visionexperiments.blogspot.com/2010/10/re-programming-rob-09571-sparkfun.html)

I received 2 of these a couple weeks ago. They were programmed with another version of firmware that is downloadable here. The motor fault lights stayed on but I was able to run motors and no fault was sent serially until I worked with my new Tamiya dual motor gear box from here also. I changed the overload value in the header file to 300 and was able to run the gear box. I also changed the code to accept a 'b' for setting both motors at the same time. Planning on making some animatronic props with them. Very happy with this product so far now!

A dip module for a next revision would be great -> no soldering required. Should change the layout / board dimensions but might be a nice alternative design to consider.

getting alerts at well under 1A, feeling a bit cheated, anything I can do to get anywhere near the claimed 2A? I only need 500-700mA.

@ryowens84, I changed the baud rate to 115200 but still no success. I wasted my whole 2 days working to run this motor driver. It is just pissing me off!!!!!!!!

Hello Manufacturers!
Can anybody write a simple arduino code that can run a motor using the serial controlled dual motor driver coz i am having a lot of trouble using it.
Thanks a lot!

Anyone here??

Hello,
I am having trouble with using this serial controlled dual motor driver. I downloaded the User's guide listed above and accted on it. I have an arduino connected via USB to my PC and i connected the Tx/Rx pins of Arduino to the Rx/Tx pins of the motor driver I mentioned. I have connected my simple DC motor to the M1+/-. power 7V to VCC pin of motor driver and ground to GND pin. Here is the code that i am using:
void setup()
{
Serial.begin(9600); //set serial to 9600 baud rate
}
void loop()
{
Serial.write('1'); // to control motor 1
Serial.write('f'); // move in forward direction
Serial.write('9'); //run at full speed
Serial.write('/r');//
delay(2000);
}
Is there anything wrong with the code?. Also tell me whether we need to turn on the on-board power jack? Thank you for your help!

Hi,how can I get new code onto the avr328?

Would there be any way to slow down the baud rate so that communicating with this with an Arduino over Softserial at 9600 baud would be possible? Also, regardless of the motor state, the Stat1 and Stat2 lights are always on, I don't think that part of the code even exists or is functional.

Any chance on having a tutorial for arduino's?

when will it be in stock?

Nice board, but limited to 5V motors. Having separate Vs will allow up to 46V motors.

Link to schematic appears to be broken.