gzaloprgm
Newbie level 3
connect pic16f877a to power in the circuit
Hi! I am having some weird problems with my pic16f877a.
First of all, the programmer (JDM2) does not recognise it, but I clearly remember that a few months ago it was recognised perfectly.
If I add +5V and GND from an external supply (connected to the ICSP connector) it works fine.
After that, I program it with WINPIC800 (data gets verified OK), but then the
problem comes:
When I put it in a simple led blinker circuit, it does nothing, every I/O pin has 0.2V but they dont disipate power (I think they are in Z state)
Already tried by changing the 20MHZ crystal to a 4 (XT), and 12, with no result.
I have a Reset pin pulled up to +V, tried with 1K, 10K, 0O, nothing helps.
My fuses are:
WRTff
LVPff
CPDff
CPff
DEBUGff
WDTENff
PWRTENff
BORENff
I am doing the circuit in a protoboard, with 1000µF capacitors and 1.2 pF to filter the power supply.
Can anyone help me?
Am I missing some thing?
Thanks!
Gzaloprgm
Hi! I am having some weird problems with my pic16f877a.
First of all, the programmer (JDM2) does not recognise it, but I clearly remember that a few months ago it was recognised perfectly.
If I add +5V and GND from an external supply (connected to the ICSP connector) it works fine.
After that, I program it with WINPIC800 (data gets verified OK), but then the
problem comes:
When I put it in a simple led blinker circuit, it does nothing, every I/O pin has 0.2V but they dont disipate power (I think they are in Z state)
Already tried by changing the 20MHZ crystal to a 4 (XT), and 12, with no result.
I have a Reset pin pulled up to +V, tried with 1K, 10K, 0O, nothing helps.
My fuses are:
WRTff
LVPff
CPDff
CPff
DEBUGff
WDTENff
PWRTENff
BORENff
I am doing the circuit in a protoboard, with 1000µF capacitors and 1.2 pF to filter the power supply.
Can anyone help me?
Am I missing some thing?
Thanks!
Gzaloprgm