Here's a version of focuser I've made with a DC breakout board, somehow "built-in" in a RPI box.
The focuser I have is with the same model as the Orion AccuFocus.
But I'm sure the same idea can be applied to stepper version with a similar setup.
What I did:
1. Add a DC jack for feeding 12V, for powering up both the PI and stepper breakout - As the motor requires a 12v to operate.
2. I got a tiny 12V-5V step down breakout for an integrated power source. The 5V feeds to the GPIO 5V input pin for powering up the RPI4. While I split one wire from the 12V input to the +ve power feed at the DC stepper board, allowing the 12V to feed to the motor unit
3. I've a got the TB6612FNG breakout for driving the motor. Note this is a DC driver board. I check the pins and I solder one side with Dupont joints, allowing the breakout to plug into the GPIO pins directly.
4. The original focuser uses a RJ10 cable and socket for connecting between the controller and the motor. I reuse the same way so I get a RJ10 jack and connect to the output pins of the DC driver board.
5. You can also see I have a RTC breakout that allows the RPI to have a real time clock.
6. Source code of the driver here: github.com/sywong2000/indi-gpio_pwm_focus
This setup gives me the advantage of:
1. a compact package connecting to the motor. Do not need an intermediate motor controller box.
2. a single 12V that feeds the PI box and the motor.
I think a similar setup can be done for stepper breakout board and motor. Yet the heat problem on the breakout board would requires some attention and further modifications.