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motor shield not working...

I was testing a geared stepper with my arduino motor shield and it suddenly stopped working. It has power in the 5V pin 'cause that's were I have my Ping sensor connected, but there seems to be none going to the motor connections. Any ideas? I can't afford another one... please tell me it's not dead.

PS: The L293DNE was a bit hot yesterday while testing other steppers, but it was working this morning. 

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What would be a good motor controller to make with a limited source of parts (range 4~5A)? There are no local suppliers in my country, so everything has to be done over the internet where shipping is crucial.

Should I move this question to another part of the forum? Thanks.

I recommend just using a SN754410NE and building a motor controller on your own.

Do you really need a 4~5Amp for your motors?
Not really, but I'm basing my needs on Rik's current measurements for Mr. Basic motors. Most of the motors I have are smaller, so I'm assuming it should be enough. He measured 2570mA stalled, but the chip you mentioned (like the L293D) has a 2A max. The L298 has 4A, so it should be something similar. I'll do my homework with the links you posted. Thanks for your help.

Thats quiet some current. Sometimes its easier to get a different pair of motors rather then buying a expencieve motor controller which can handle your requirenments. If you decide to buy something pre-made I'd recommend you to look at Pololu's products. They have very good controllers and ship fast.

If you decide to build something stay away from the L298 as its a bitch to assemble. Pinout is rather nasty. Especially if you're making your own PCB.  It's easier to connect the L293(sn754410ne) which also can be connected in parallel

And your code is ???

Have you run tests of turning one input on and off with the multimeter attached to the h-bridge outputs?

When yu turn one input of the h-bridge on, you should see the corresponding output also go  high. as in 5 volts at the input, should give the motor voltage output minus about 1.2 volts.

I'm using the sample code for the motor shield from here: http://www.ladyada.net/make/mshield/use.html I believe the RELEASE command sets the LOW value you mentioned. The output voltage is about .5V, which seems strange to me. Input is 9-12V.

#include <AFMotor.h>

AF_DCMotor motor(2, MOTOR12_64KHZ); // create motor #2, 64KHz pwm

void setup() {
Serial.begin(9600); // set up Serial library at 9600 bps
Serial.println("Motor test!");

motor.setSpeed(200); // set the speed to 200/255

void loop() {

motor.run(FORWARD); // turn it on going forward

motor.run(BACKWARD); // the other way

motor.run(RELEASE); // stopped


First check if you really do have a geared STEPPER motor or a geared DC motor. How many wires are coming out of the motor? If there are only 2, it`s a DC motor but if there are more than 2 wires it`s most likely a stepper.

IF you have confirmed it`s a DC motor AND you just recently changed the motor connections.. then likely you haven`t changed the code to reflect the different connections.  AF_DCMotor motor(2, MOTOR12_64KHZ); line should probably be changed to something like AF_DCMotor motor(1, MOTOR12_64KHZ); but check the documentation on that site.

IF you have confirmed it`s a stepper, then your problem is that the code you are using is for a DC motor. Stepper motor code and wiring diagram is on the same page you linked.

I was testing a stepper (4 wires) (bipolar) with the corresponding code. Then I tried to test a DC motor with the code posted above to check the motor pins on the shield. I can distinguish between steppers and motors.

I asked about this issue in the adafruit forum and someone told me the problem is probably a fried chip. My new question is if one of the chips dies, what happens to the other one? Are they connected to each other? (L293DNE)

Thanks for replying.

Everything will be connected through logic and motor voltage, and ground.

I guess whether or not both chips have fried comes down to why the chip has fried in the first place. Sorry, can`t really help much. As a last resort you could try swapping the chips but you`d have to get out the soldering iron to do that :/

First; change the title of your post!

 Secondly; check your circuits with a multimeter.