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Powering motors with Pololu DRV8835 Dual Motor Driver

Posted: Sun Jun 28, 2015 6:18 am
by mpatronska
Hi,

I intend to connect 2 motors to the Raspberry Pi using the Pololu DRV8835 Dual Motor Driver (https://www.pololu.com/picture/view/0J5735)

Can I power both the Raspberry Pi and the motors using an external USB battery pack? Or if I use the battery pack for powering the Pi, I should use different batteries for the motors.

If I can power all with the USB battery pack, how should I do the electric circuit so that the motors will be powering by the USB battery pack?

Thanks.

Re: Powering motors with Pololu DRV8835 Dual Motor Driver

Posted: Sun Jun 28, 2015 9:01 am
by drgeoff
In theory you can use a common supply for motors and a RPi. However:

1. The RPi must be powered by 5 volts (+/- a few percent). Is that OK for the motors and driver?

2. Some motors are electrically noisy. In extreme cases that can disturb the RPi.

3. Check the current supplying capability of the USB battery unit. Many are rated at only 1 amp which may be too low for RPi plus motors.

Re: Powering motors with Pololu DRV8835 Dual Motor Driver

Posted: Sun Jun 28, 2015 12:36 pm
by mpatronska
Thanks for the reply.

1. The motors need about 6V.
3. The battery pack has two USB ports, the one is 1A and the other 2.4A.

Re: Powering motors with Pololu DRV8835 Dual Motor Driver

Posted: Sun Jun 28, 2015 4:08 pm
by mikronauts
I use two separate supplies - keeps motor "noise" away from the Pi, and prevents brown outs in case of a motor stalling.

http://www.mikronauts.com/robot-zoo/elf-2wd-pi-robot/