PIC 12F629 – 12F675 Astable Timer

This software functions as a long period astable mutivibrator. The mark and space period can be set from 1 second up to a maximum 65535 seconds (18h12m15s). Using the internal 4Mhz RC oscillator delays with an accuracy of 99% or better can be achieved The code also implements an edge triggered reset and an active low hold function. The reset edge can be configured for rising or falling edge. The hold function is active low and stretches the timed period for as long as the hold input is held low.

In addition to this up to 128 mark/space time pairs can be used which are executed sequentially allowing complex pulse trains to be generated.