Drive system software

[dimembermatt]

See this branch

• [x] interface basic directionality movement

• [x] turn on motor with PWM

• [x] move backwards and forward on command

• [x] operate two motors on 1 PWM channel

• [x] operate four motors on 2 PWM channels

• [x] read data from encoders

• [x] map encoder data to actual distance (verification)

• VNH5019 Motor Driver user guide

• VNH5019 Motor Driver datasheet - contains input pin logic tables

• PWM physics tutorial

• Mechanum drive tutorial

• Motor and Encoder datasheet

[dimembermatt]

Update 2/20/20.

Soldered the motor drivers, I just need to find a power source to the MTR PWR and MTR GND and connect the pins from the MC to the driver and get it to turn on.

I've already confirmed that the INA/INB pins are turned on as expected (for parts of forwards and backwards, at least). An easier test than individually testing pins (and resetting the pi when I accidentally short it) would be to turn it on and check if it is moving in the right direction.

Some fiddling needs to be done to duty cycle and frequency to make the motor drive an expected distance; I would advise initially setting the speed to be slow and manipulating the time the motors are on to get distance - once we get more accurate we can increase speed and decrease on time.

Hoping to get this done by 2/21/20. Self imposed deadline for a properly moving base is 2/28/20.

[dimembermatt]

Update 2/22/20.

Motors for forward movement all driven. Next step is to set up encoders and start reading measurements.