I'm with Carl and Thomas here ... it's possible that there was solder bridge between the pins of the op-amp, which was removed when the op-amp was changed.
To be fair to the author, he did consider using another micro-controller but decided against it because he was already committed to the part he was using, having written the code and laid out the...
Informative write-up as ever. We're still learning from Bob Pease thanks to your column. That's a good point from Harry Holt too!
Sponsored Introduction Continue on to (or wait seconds) ×