I'm commissioning a Pololu MC32926 Motorshield on an Uno Rev3. Using the Pololu Demo script (below) modified only to reduce the Serial speed to 9600 (I was getting some garbled characters at the original speed).
Motor 1 works fine. Can't get anything on the Motor 2 side: no leds, no power on the relevant terminals.
Is there anything other than a fried chip on the board will cause these symptoms?
Thanks
#include "DualMC33926MotorShield.h"
DualMC33926MotorShield md;
void stopIfFault()
{
if (md.getFault())
{
Serial.println("fault");
while(1);
}
}
void setup()
{
Serial.begin(9600);
Serial.println("Dual MC33926 Motor Shield");
md.init();
}
void loop()
{
for (int i = 0; i <= 400; i++)
{
md.setM1Speed(i);
stopIfFault();
if (abs(i)%200 == 100)
{
Serial.print("M1 current: ");
Serial.println(md.getM1CurrentMilliamps());
}
delay(2);
}
for (int i = 400; i >= -400; i--)
{
md.setM1Speed(i);
stopIfFault();
if (abs(i)%200 == 100)
{
Serial.print("M1 current: ");
Serial.println(md.getM1CurrentMilliamps());
}
delay(2);
}
for (int i = -400; i <= 0; i++)
{
md.setM1Speed(i);
stopIfFault();
if (abs(i)%200 == 100)
{
Serial.print("M1 current: ");
Serial.println(md.getM1CurrentMilliamps());
}
delay(2);
}
for (int i = 0; i <= 400; i++)
{
md.setM2Speed(i);
stopIfFault();
if (abs(i)%200 == 100)
{
Serial.print("M2 current: ");
Serial.println(md.getM2CurrentMilliamps());
}
delay(2);
}
for (int i = 400; i >= -400; i--)
{
md.setM2Speed(i);
stopIfFault();
if (abs(i)%200 == 100)
{
Serial.print("M2 current: ");
Serial.println(md.getM2CurrentMilliamps());
}
delay(2);
}
for (int i = -400; i <= 0; i++)
{
md.setM2Speed(i);
stopIfFault();
if (abs(i)%200 == 100)
{
Serial.print("M2 current: ");
Serial.println(md.getM2CurrentMilliamps());
}
delay(2);
}
}
It's just this Pololu MC33926 mounted up as a shield on a Arduino Uno Rev 3. No additional or external components, other than two DC motors wired to the screw terminals on the M1 and M2 channels. The LEDs I'm referring to are on the board. I can provide an image or video of the board.
I'm sure everyone who is familiar with this shield will know the Pololu supplied demo/test script.
If I swap the motors the one powered on the M1 side works, and the on board LEDS flash as you'd expect for the demo, and the motor on that side works. Nothing on the M2 side.
You got the idea!
You omitted all logic control lines.
Does that shield piggy back to the controller?
How is that 9-6 volt generated?
Not by a PP3 I hope.
Power 8*1.2V rechargeable AA batteries - 10.2 volts at the terminals according to my meter.
Not sure what you mean by this.
There is absolutely nothing else: all the other logic is either on the board, or in the interface between the Uno and the board. The demo: which is all I have for this board right now; doesn't even specify which Arduino pins are actually used. I'm trying to get my head round the documentation, but its not written for a software guy like me, is voluminous and covers all sorts of uses beyond and Arduino Shield, and the DC motor apps I've developed using the Arduino Motor Shield Rev3.
Always unplug all power before disconnecting any other device!
Check the shield library, which controller it's written for. All Arduino controllers are not the same and libraries might not work for some of the Arduinos.
GUESSING below!
UNO R3 is a universal, old reliable "guy" but..... That library might use harware functions not existing in the UNO.
The initial problem sounds like "something" is not enabled by some reason. Hardware or software missings? Straps, external connection?
I'm using the library from the Pololu web site, so I'd expect it to work.
The examples (from Pololu) all seem to use the the UNO Rev3, so it doesn't seem likely that's the problem (but I agree possible).
Also the fact that it's driving (or was) the M1 channel satisfactorily, makes me lean towards hardware on the M2 side. I'm specifically worried there may have been a short (i.e. narrow solder bridge) between the M2A pad and the VNN pad on the Shield. I thought I'd checked for these sort of faults with my meter, but may be I missed this.
Anyway, @Railroller, thanks for cheering me up and re-motivating me.
