#154 Switching between PWM and plain fails

[Simon Walters]

Swapping between pwm and standard off/on on a pin fails after 250 cycles

in my robot prog, I use pwm to control motors but set pins to 0 to switch them off when idle

if I have 2 motors - it fails twice as quickly :(

Example code to show failure mode

https://pastebin.com/YLXHJ6GH

[Ben Croston]

Fix added to source code library. Will be included in next release.