DT’s Elapsed Timer Magic Trick

[Art]

Thanks
It wasn’t my idea to use timer1 values as RAM that survives WDT reset,
but I figure as long as you haven’t started timer1, you could just write the count into
one of the timer1 bytes instead of on-chip EEPROM and read the value after the reset.

For my clock board I have swapped the 8MHz crystal with a 20MHz crystal,
and added a dual flip flop to divide two of the clocks, so now have:
8,12,16,20 & 24MHz. One dual more flip flop, and I’ll have 6 & 10MHz as well.
It has been reliable so far with the freqs I can test, bust suspect any 1MHz increment is easy to detect.