I wish to add a frequency counter to a square wave generator (20Hz to 3kHz, TTL) using the COUNT instruction, and to keep it really simple was going to use a 16F628, 8x1 LCD and 100nF decoupling capacitor!

Intended to use the internal oscillator and tweak the count period to get a fairly accurate reading (with 3%?).

But wondered if the internal clock drifted with age, temperature, etc?

Thanks