100:1 Micro Metal GearMotor HP

Support Motor controllers/drivers and motors
1

Hi I would like to ask if the 100:1 micro Metal gearMotor HP can be drived by DRV8835 Dual Motor Driver Kit for Raspberry Pi? In the specs the 100:1 the stall current rate is 1600ma. and for the DRV8835 output current is only 1.2A and max is 1.5A.

The reason I ask because I already have both products and wanna make sure that this will not cause any problem on the DVR8835.

2

Hello.

The DRV8835 has some built-in protections that make it fairly robust, and you should not stall those motors anyway, so it should be fine. If you want to really safe, you could implement some kind of acceleration limiting to reduce the inrush current when the motor starts or changes direction quickly (since your motor can briefly draw up to twice the stall current when going from full forward to full reverse). You might also consider limiting your maximum duty cycle.

-Derrill

3

Thanks for your reply. By the way i have also drv8833 with max current upto 2a, do you recomment to use it instead or drv8835? What are the difference between the two?

Im also interested on acceleration limiting but im new in electronics. Can you direct me where to start? Thanks again.

4

The DRV8833 requires four PWM signals to control two bidirectional motors, so it is generally not appropriate for using with the Raspberry Pi since the Raspberry Pi only has two PWM outputs.

Acceleration limiting would be done in your code, and at is simplest you could incrementally increase the speed (usually by adding to a speed variable in a loop). If you get started and find you need some additional help, you can post your code here on the forum, and I would be glad to look at it.

-Derrill

5

Thanks for the info now I know the difference of both so i will use my DRV8835 instead of DRV8833. By the way some suggested to put a ceramic capacitors (100 nF) in parallel with the motor. Is this applicable in DRV8835?

I will post my code later.

Thanks Again.

6

In general, adding capacitors like that is often a good idea to help eliminate motor noise. However, our DRV8835 Dual Motor Driver Kit for Raspberry Pi already has some capacitors built onto the board, and we have found that the DRV8835 sometimes does not work well with additional capacitors.

-Derrill