Connect 2 Drv8825 Board's To One Raspberry pi

Robotics and electronics discussion Resources
1

Is it possible :thinking: to connect 2 drv8825 boards to one raspberry pi, and control the boards at the same time? I currently am using one at a time successfully. All the help that could be provided. :grinning:

2

Hello.

We do not have any resources specific to controlling multiple stepper motor drivers from a single Raspberry Pi, but I do not see any reason why you would not be able to do that. However, since the Raspberry Pi does not use a real-time operating system, it might not be practical if you need precise timing.

One alternative option might be to use a separate microcontroller with a real-time operating system, such as an Arduino or our Arduino-compatible A-Star controllers, to handle the communication to the drivers and send it commands for what to do from your Raspberry Pi using some higher level communication (e.g. USB or TTL serial).

Another option would be to use 2 of the Tic T825 USB stepper motor controllers, which use the same DRV8825 driver but directly accept higher level interfaces such as USB, TTL serial, I2C, analog voltage, and hobby RC signals. They also have a lot of additional features like configurable acceleration and deceleration limiting, digitally adjustable current limit, and optional limit or kill switches.

Brandon

3

Thanks a lot for the advice. Do I need RTOS on the Raspberry Pi to connect to 2 drv8825 boards that are then connected to a stepper motor each? And how would I connect the boards to the raspberry, in what configuration?

4

Are you asking about using two Tic T825 controllers or DRV8825 carriers?

Brandon

5

The DRV8825 boards. :grinning:

6

Hello.

Both the Tic T825 and the DRV8825 carriers use the DRV8825 driver chip, but it sounds like you are asking about the carriers.

Whether or not you need a real time operating system depends on how crucial precision is in your application.

If you already have one working with your Raspberry Pi successfully, adding a second should be very similar. As far as connections, you can find a minimal wiring diagram under the “Using the driver” section of the DRV8825 carrier’s product page. I am not sure what you mean when you ask what configuration the DRV8825 carriers should be in. If you are referring to the microstepping mode, that also depends on your application, and not the controller sending the step signals.

Brandon

7

Thanks for all the help :+1:, and I will get back to you after I hook everything up with the information that you have provided. :wave: