Hi Paul,
yes the other problem took several months to pin down, and was due to my driving a flashing LED ( with a 1k) off the A port, which is supplied from the Avcc believe it or not. Horrible. Hard to believe but that's what it was.
I have a tube of smd 4060's, and with virtually no other components, could get long periods with a short RC. I don't like using a 555 with periods longer than a few seconds because it is then dependent on good low leakage caps of high value, ( T = 0.69RC from memory ) whereas the RC of a 4040 is ms for the same end result, because of its 2^14 counter/divider. Very convenient.
↧