Last night I was finally able to piece together my most viable prototype yet. It was so viable that I also got a chance to test out my firmware code! Many bug fixes later, I was greeted by this awesome display:
The problem I'm currently running into is that both motors experience too much friction and therefore aren't producing consistent steps. I believe the friction coupled with loose belts causes the stepper motors to essentially skip arbitrarily. I'm going to tackle this one axis at a time. After some brainstorming this evening, I have a plan to solve horizontal movement so I will be prototyping some new components within the next few days.
Many good things happened too! For one, the fact both motors are running at the same time proves that my molex power supply is capable of handling the load (previously this was purely hypothetical). And today, my custom oshpark boards shipped!! It's my first time designing a circuit board, so I'm taking bets as to whether it works out of the box or not :)
Another great win is that my firmware is more or less working now. Yesterday I added a bunch of parallelism, bug fixes, and math - all of which culminates in the ability to send the telescope an angle for each motor and it calculates that into delta steps for the motors while keeping track of current state and updating an AWS IoT device thing. Currently I am implementing the ability to send .lua scripts to the telescope which have full control of the "device state" and can execute AWS Lambda functions for online processing of information.
I'm really excited with how things have turned out and will keep y'all posted as I make more progress on fixing this gear friction issue.