PICStep Firmware V0.9

This is a first public release of the PICStep firmware. It hasn't been physically tested with any hardware yet, but it has been extensively tested on a testing breadboard with LED's, and in the MPLAB simulator. Any destruction or damaged caused by the use of this firmware is not my fault! :) (But it works good anyhow! 8)

The step calculations take around 57-63 instructions (including branches). So at 20MHz (200ns per instructions) by my ruff calculations the firmware should be able to step in just under 0.0134 milliseconds. Which in theory will allow in 1/8th mode a maximum of 2700RPM with a 1.8 degree motor.

This firmware supports 1/8, 1/4, 1/2 and Full (all partial step modes have full torque compensation). These modes are switch-able via RA4 and RA5 while running, but mode switching can result in a few misaligned steps until the step tables align themselves back to the right timing.

The firmware upon power-up leaves the coils uncharged until the first initial step is received. This a small safety feature to stop motor and coils energizing while the controllers are powering up.

The pin layout is as per the schematic below. This is licensed under GPL, so any modifications etc etc must come back to me. Also this codes cannot be used in any commercial product unless your code is in accordance with the GPL license.