Precision Stepper Driver Development

I need clean, well-commented code that drives a stepper motor so a load of more than 5 kg can rotate a box and hold each 90-degree position with better than ±1 ° accuracy. The system will be powered from a 12 V DC rail, so any acceleration profiles, current-limiting strategies, or micro-stepping choices have to respect that constraint.

The deliverable is the complete motor-control program (C/C++ or Python on a microcontroller such as Arduino, STM32, or Raspberry Pi Pico—whichever you recommend for best torque at 12 V), along with concise setup instructions and pin mapping. Your code should include:

• Initialization of the driver and any required libraries
• A simple API: rotateClockwise90(), rotateCounterClockwise90(), and stop()
• Homing logic to guarantee absolute positioning after power-up
• End-of-movement verification so the box cannot drift outside the ±1 ° window

Please attach or link to previous projects where you achieved comparable precision with stepper motors, noting the hardware you used. If you can supply a brief video or oscilloscope capture that proves smooth micro-stepping or holding torque, that would be a plus.