Quad Encoders and Raspberry Pi

So I’m curious, is it possible to use the Vex Quadrature Encoder with the Raspberry Pi. Specifically I am using vex motors powered by the Raspberry Pi to make a Rubik’s Cube solver, but I need a better way to run the motors for a specific amount of time. Right now I’m just using the built in timer stuff for python, but there is too much variance in how far the motors turn for it to be viable for me.

So my main question: is is possible to use Vex Quad Encoders with the Raspberry Pi directly, or should I just use the Raspberry Pi for image recognition and run the motors and encoders with an arduino?

Using a quad encoder directly with a RasPi is possible, but I don’t think it’s the easiest way to go. And you likely want to use 3 or so encoders. That’s a lot of interrupt handling, or (yikes!) polling. You can end up spending a lot of time (hours, days) fruitlessly chasing problems from missing the quadrature transitions. Arduinos are cheap and easy to use. I’d tend to run openCV for image stuff on the RasPi, and do motor/encoder things on one or more arduinos.

I figured that would be the case, though the whole project should only need 2 motors, one of which could be a servo. With that in mind, if the servo works the same way as it does on the cortex when connected to the raspberry pi, it should leave me only needing one encoder? Would I run into the same problems still, or should I still just go with the arduino setup?

Have you thought about using stepper motors?

I have thought about using stepper motors, but the problem is that I don’t have access to stepper motors without purchasing them, and it’s the same story with an arduino. Either way I would have to spend money, and from what I can tell the stepper motors are going to be more expensive overall, so I should just get an arduino. Right?

Probably buy a cheap arduino. Remember you need 2 with at least 2 interrupt ports per encoder. So if you want 2 encoders the arduino needs 4 interrupts.