High tick freq., starving and overhead?

albinst wrote on Saturday, September 26, 2009:


I’m working on a open source midi controller (keyboard). It has a keyboard, an LCD display and 8 rotary encoders. I would like the keyboard matrix (8x24 switches) to be scanned exactly every 1ms (there are to switches under each key for measuring velocity, because of this bouncing is not a big problem). The encoders and LCD is not time critical. I’m using an atmega128 running at 12MHz.

What Tick Frequency would be appropriate?? What is the overhead of the rtos kernel? Instructions / tick, instructions / context switch?

Atb, Albin

edwards3 wrote on Saturday, September 26, 2009:

Why not just use a tick frequency of 1KHz then use the tick hook to do the scanning?