Driving a laser from Mechaduino

[Andrew Hodgson]

Hi,

I'm a newbie, just got my Mechaduinos, destroyed one already by connecting up stepper phases incorrectly, now a bit more cautious in what I do with it, so looking for a little advice/guidance...

My project is a high-precision pan-tilt laser turret (to help mark out sundial delineations on walls/ceiling).

I'd like to drive the laser from a spare pin on the Mechaduino rather than from the Raspberry Pi that will be controlling the Mechaduinos.

The Mechaduino manual does not discuss the usability of the exposed pins - maybe because it's obvious to more experienced people.

D0, D1, D2 are used for dir, step and enable, but I believe I could use D3 ("TEST1") to drive the laser (with its integrated resistor) - all I'd have to do is comment out the line

#define ENABLE_PROFILE_IO // Define to enable profiling I/O pins

Then the code in the Controller.cpp control loop won't drive it - that looks like it was simply pulsing the line each run of the control loop for testing during development.

But what about the other exposed pins, A0 (D24), A1 (D25), A3 (D27), A4 (D28), A5 (D29). I don't see these being used anywhere. They are mentioned as analog pins - does that mean I can't use one to drive my laser?

What do you recommend - reusing TEST1 (D3), or, say A0 (D24)?

TIA.