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Pololu Dual MC33926 Motor Driver with Arduino Mega 2560


#1

Hello Friends,

I recently bought Pololu Dual MC33926 Motor Driver Shield for Arduino to run with Arduino Mega 2560 to drive 2 DC motors.
I ran the demo program that comes with the library. The motors are running well but there was some alarm. I don’t know why.
I ran the driver with Arduino Uno and there is no alarm… the motors are running well…

Please let me know how to solve the alarm problem. Thank you.


#2

Hello.

Can you give more details about what happens when you use the shield with the Arduino Mega? I’m not sure what you mean when you say there was some alarm. Is a fault being indicated? The demo program should print “fault” to the serial monitor if this happens. Do the motors continue to run?

-Brandon


#3

there is no fault indicated at the serial monitor and the motors are turning back and ford. However, there seem to be more current flowing using Mega than Uno. And the alarm like sound seems to come from the two motors.

I have no idea why it is working without sound in Arduino Uno and there is some sound using Mega.

Thank you for your support


#4

Here are some data from my monitor

When using Arduino Mega 2560
Dual MC33926 Motor Shield M1 current: 0 M1 current: 0 M1 current: 0 M1 current: 0 M1 current: 0 M1 current: 0 M1 current: 0 M1 current: 0 M2 current: 0 M2 current: 0 M2 current: 0 M2 current: 954 M2 current: 657 M2 current: 1188 M2 current: 216 M2 current: 1602 M1 current: 909 M1 current: 1728 M1 current: 324 M1 current: 711 M1 current: 1332 M1 current: 2178 M1 current: 387 M1 current: 180 M2 current: 1611 M2 current: 2556 M2 current: 459 M2 current: 45 M2 current: 2142 M2 current: 3195 M2 current: 675 M2 current: 72 M1 current: 1107 M1 current: 3240 M1 current: 1143 M1 current: 99 M1 current: 351 M1 current: 2727 M1 current: 1422 M1 current: 144 M2 current: 81 M2 current: 1656 M2 current: 1656 M2 current: 216 M2 current: 126 M2 current: 1350 M2 current: 1458 M2 current: 315 M1 current: 198 M1 current: 1242 M1 current: 1368 M1 current: 405 M1 current: 252 M1 current: 1017 M1 current: 1161 M1 current: 531 M2 current: 279 M2 current: 603 M2 current: 405 M2 current: 693 M2 current: 486 M2 current: 891 M2 current: 162 M2 current: 1422 M1 current: 819 M1 current: 1485 M1 current: 270 M1 current: 1026 M1 current: 1035 M1 current: 1539 M1 current: 261 M1 current: 873 M2 current: 1134 M2 current: 1863 M2 current: 369 M2 current: 81 M2 current: 1728 M2 current: 2520 M2 current: 477 M2 current: 36 fault
"fault" means I switched off the power…

When using with Arduino Uno
Dual MC33926 Motor Shield M1 current: 0 M1 current: 0 M1 current: 0 M1 current: 0 M1 current: 0 M1 current: 0 M1 current: 0 M1 current: 0 M2 current: 243 M2 current: 900 M2 current: 0 M2 current: 0 M2 current: 243 M2 current: 891 M2 current: 0 M2 current: 0 M1 current: 279 M1 current: 1350 M1 current: 0 M1 current: 0 M1 current: 279 M1 current: 1179 M1 current: 0 M1 current: 0 M2 current: 216 M2 current: 882 M2 current: 0 M2 current: 0 M2 current: 216 M2 current: 855 M2 current: 0 M2 current: 0 M1 current: 297 M1 current: 1251 M1 current: 0 M1 current: 0 M1 current: 279 M1 current: 1188 M1 current: 0 M1 current: 0 M2 current: 225 M2 current: 945 M2 current: 0 M2 current: 0 M2 current: 225 M2 current: 891 M2 current: 0 M2 current: 0 M1 current: 279 M1 current: 1233 M1 current: 0 M1 current: 0 fault


#5

Hello.

Could you post a video of your setup with the Arduino Mega so we can try to hear the noise? If not, could you describe the noise? I suspect the sound you are hearing is the PWM frequency. When using our Arduino library for the MC33926 shield on an Arduino Uno, the PWM frequency gets configured to 20kHz, which is above the range of human hearing. Our library does not configure the PWM frequency this way when using the Arduino Mega.

As far as the current draw difference, is everything else the same between your two setups except the Arduino board (e.g. the same motors, same power supply, and using the same unmodified demo code on both)?

-Brandon


#6

This one is with Mega

And This one is with Uno

All the settings are the same.

Thank you for your support.


#7

It sounds like that noise is probably from the default 490Hz PWM output from the Mega. This forum post by Claire shows how the Arduino library for the VNH5019 shield can be modified to use 20kHz PWM signals with the Arduino Mega; you might try making similar modifications to the Arduino library for the MC33926 shield.

By the way, it looks like you are using two 12V batteries to power the MC33926 shield. Please note that this shield’s maximum operating voltage rating is 28V, and when fully changed, two 12V batteries could exceed this voltage. Also, the MC33926 shield is rated for a continuous output current per channel of 3A (with a peak of 5A). From the look of those motors, the MC33926 shield might be underpowered for your application. You might want to double check that they fall within the current ratings of the shield when using 24V.

-Brandon