Alrighty Then!

So the same issue hit me twice: the on-chip, programmable pullups are only reliably doing their work if the environment is clean: electrical noise from steppers triggered interrupts the zener diode on the pwm1b pin4 of a digistump made it float around Adding 10k/4k7 pullups and 33n debounce caps did the trick.

As a side-project I started to develop on the Arduino platform (more on the project-of-the-day later). First Steps Getting going on windows was easy: setting up Arduino 1.0.1, compiling and running the “blink” demo, changing the frequency etc … was straightforward. Then: i found grbl. Flashing the premade 0.8a firmware from grbl – instant success. [...]