Serial Monitor Not Responsive After Powering Stepper Motor Driver

Development Tools IDE 1.x
1

Hello,

I'm using the Arduino Uno to run a the A4988 stepper driver. I have the Arduino connected to my macbook and using the serial monitor. Everything works fine but if I start the serial monitor while the stepper motor driver is not connected to Arduino 5V, and then while it is running I connect the driver to 5V, the serial monitor stops working. Any idea as to why this happens?

Some more information:

  • The serial monitor works again if I close it and open it
  • This issue does not happen if I power the driver with 3.3

TL;DR
The serial monitor becomes unresponsive when I power motor driver with 5V, and becomes responsive again if I close and re-open it. This does not happen if I power with 3.3V.

Thanks

2

How do you power the shield and the steppers?

If you power everything from the arduino's 5V, you might temporarily overload the mac's usb port which can reset the arduino and hence the serial port is lost. It's a thought, not said that it happens.

Please show us how everything is wired (not a photo, a photo/scan of a diagram) and provide a link to the steppers.

You can use the pin 13 led for some diagnostics. In setup, switch it on and switch it off after e.g. 2 seconds. Run your test; if the led switches on when you power the driver board, the arduino went through a reset.

3

sterretje:
How do you power the shield and the steppers?

If you power everything from the arduino's 5V, you might temporarily overload the mac's usb port which can reset the arduino and hence the serial port is lost. It's a thought, not said that it happens.

Please show us how everything is wired (not a photo, a photo/scan of a diagram) and provide a link to the steppers.

You can use the pin 13 led for some diagnostics. In setup, switch it on and switch it off after e.g. 2 seconds. Run your test; if the led switches on when you power the driver board, the arduino went through a reset.

I am not using a shield. It's a A4988 stepper motor driver chip. I am powering the driver from the Arduino. The specs call for a 3-5 volts power source. The motors are powered by the driver using a 12V power source.

Yeah sometimes I have seen that happen but then I would get an error message by the Mac's OS wouldn't I? In this case I am not receiving an error message. I will do your suggested tests and get back to you. Thanks!