joflahe Posted February 27, 2009 Report Share Posted February 27, 2009 Hello all. I built the Midi merger with a 16F88. It works very nicely, and thank you. I had one little problem, which I'd like to describe in case it might help someone else. When I first powered it up, the power LED would light up and stay lit for a random time, some seconds, and then go out, and the unit would then not respond. When I would move my hand close to the unit, it might turn on again for several seconds.The problem was that pin 4 of the 16F88, a pin not used in this circuit, was floating. The PDF with the circuit diagram shows no connection to it. Apparently, in some versions of the chip or under some other unknown circumstances, this pin is a master clear. Being a CMOS input, it wandered where it would, holding the unit reset. A 10 kohm pullup resistor from pin 4 to Vcc fixed the problem. It would probably work with a direct connection as well.-- John O'Flaherty Quote Link to comment Share on other sites More sharing options...
nILS Posted February 27, 2009 Report Share Posted February 27, 2009 Welcome aboard joflahe!...and thanks for the input ;-)@WIKIMARKER Quote Link to comment Share on other sites More sharing options...
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