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motor shield not working...

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By e-square12

September 26, 2009
e-square12's picture

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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By e-square12
@ Sun, 2009-09-27 11:46
e-square12's picture

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.

By Simon Z
@ Sun, 2009-09-27 15:59
Simon Z's picture

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

Do you really need a 4~5Amp for your motors?
By e-square12
@ Sun, 2009-09-27 16:51
e-square12's picture
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.
By Simon Z
@ Mon, 2009-09-28 21:04
Simon Z's picture

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. 

By robologist
@ Sat, 2009-09-26 22:22
robologist's picture

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.

By e-square12
@ Sat, 2009-09-26 23:17
e-square12's picture

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() {
Serial.print("tick");

  motor.run(FORWARD);      // turn it on going forward
delay(1000);

Serial.print("tock");
  motor.run(BACKWARD);     // the other way
delay(1000);

Serial.print("tack");
  motor.run(RELEASE);      // stopped
delay(1000);
}

 

By ezekiel181
@ Sun, 2009-09-27 06:30
ezekiel181's picture

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.

By e-square12
@ Sun, 2009-09-27 08:13
e-square12's picture

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.

By ezekiel181
@ Sun, 2009-09-27 08:45
ezekiel181's picture

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 :/

By Simon Z
@ Sat, 2009-09-26 21:10
Simon Z's picture

First; change the title of your post!

 Secondly; check your circuits with a multimeter.

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