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fadibasic
- 26th April 2008, 23:44
Hi guys,
I am experiencing a weird behavior of the pic16F877.

I have 24 led(s) That I have distributed on port D, C, E, and A.

I wrote a code were the first 12 Leds will trun ON, and after every PAUSE 500, A LED will trun off and another LED will trun ON from the second set of 12 LEDs.
Everything went well except 1 LED didn't turn ON at all. (I checked to see if it is burnt, but it is not). The LED was on PORTA.4

Then I wrote another code, where all 24 LEDs will turn ON, and They will turn off, one at a time.

I had a weird behavior: 6 LEDS didn't work and they are at PORTA.2, .3, .4, .5, PORTE.0, .2

Have anyone experienced this behavior?
Please if you have any advice or answer I will appreciate it.
Thanks

mister_e
- 27th April 2008, 00:03
is there any chance you forgot to disable the analog converters?
ADCON1=7

PortA Doesn't Work & Common 8-Bit PICŪ Microcontroller I/O Pin Issues
http://www.picbasic.co.uk/forum/showthread.php?t=561


If i remember correctly, PORTA.4 is an open-drain output, so the LED has to be connected between Vdd and PORTA.4

Pin RA4 doesn't work
http://www.picbasic.co.uk/forum/showthread.php?t=562