Ah! Good point.Reading tea leaves, I *hope* that the reason there are no base resistors is that the three transistors are MOSFETs.
ak
Power could be supplied by the red and black wires shown in the first image of this thread. PicKit will detect that voltage and will not attempt to power the board.Please double check the supply and ground circuits. There is still the problem of shorting.
Second concern is the use of a PicKit to program without an additional Vcc connection. Is a "Y" adapter used on the ICSP header? A PicKit can supply very little current (about 30 mA or so). How does the TS know the chip is blank? Was the chip identified by the PicKit and was the programming sequence otherwise normal (e.g., no "overcurrent" warnings)?
Mine don't do that. I need to specify how to supply the target; albeit, using an external supply is default.Power could be supplied by the red and black wires shown in the first image of this thread. PicKit will detect that voltage and will not attempt to power the board.
I often use these to eliminate the additional base resistor:Reading tea leaves, I *hope* that the reason there are no base resistors is that the three transistors are MOSFETs.
ak
Yes, or (PNP) emitter followers.Reading tea leaves, I *hope* that the reason there are no base resistors is that the three transistors are MOSFETs.
ak
I was thinking that too... Also All five LED's powered through a small transistor's not a good Idea..Reading tea leaves, I *hope* that the reason there are no base resistors is that the three transistors are MOSFETs.
ak
Agree that the buttons should be at the bottom.I think the board is upside down.
2 LEDs count (0,1,2,3), so for a 24 h clock, that should be the first digit.
Buttons at the bottom.
It is a new chip. See post #34.Having a chip simply go blank is a very rare occurrence according to Microchip:
View attachment 154956
The minimum life expected for program flash memory is 40 years.
Back to my concern expressed in post #23: How did you determine the chip was "blank?" I ask that not to assign blame, but rather to be sure there is a problem that needs to be solved.
I did read #34, #1 , and all of the others. My question refers to the original chip with a vanishing code. THAT is very unusual. Maybe that happened. But maybe the TS misunderstood some messages while testing it in circuit and took them to mean the chip was blank. Since the chip has been removed, it would be a simple matter to insert in it a solderless breadboard, establish communication with it (use short wires!), and confirm it is blank.It is a new chip. See post #34.
The chip vanished, not the code.My question refers to the original chip with a vanishing code.