bytter said:
Hi there,
I've bought the Velleman programmer for learning PIC programming. I've successfully played w/ a PIC16F628A. Now I want to do something advanced and got myself a 16F877A. I've tried using the ICSP port on the programmer to connect to the PIC on a breadboard, but all I can read from it is 3FFF (except for the Device-ID that reads 3DCC). I'm unable to write anything.
I'm connecting the following way:
ICSP PIN -> PIC
1 - 1
2 - 11
3 - 12
4 - 40
5 - 39
I'm also shorting PIC PINs 11 to 32 and 12 to 31.
Can anyone please help me? Is there something missing? Is the oscilator needed to program it?
Thanks..
Hugo Ferreira
I'm using the same K8048 programmer.
I'm trying to program the 16f877A with a linux program.
I had the same problem as you described.
My solution was to shorten the ICSP wires to the 16f877A to aprox. 20 cm.
AND apply a 150 pF condensator from the RB7/PGD wire to ground
AND apply a 100 ohm resistor in the RB6/PGC wire with a 150 pF condensator at the chip side of the resistor to ground (low pass filtering PGC)
I mounted the R and C's on my bradboard as close to the chip pins as possible.
Furthermore in case of a brand new 16f877A (LVP is enabled by default) connect pins 36 RB3/16PGM and 38 RB5/18PGM to ground with two 10k resistors.
This is necessary only at first time HV programming. Put LVP_off in the config word and disable code protection in the config word.
Now I am able to identify and program the 16F877A with K8048 ICSP.
Verifying the programmed 16f877A still gives problems (not at all locations in pic program memory) but this is probably a bug in the linux programming software.
I'm using this software:
**broken link removed**
I will try the solution with the Velleman software under windows XP as soon as possible.
Connect pins 11 and 32 to Vdd (+5V)
Connect pins 12 and 31 to Vss (gnd)
I suppose that is wat you means with:
I'm also shorting PIC PINs 11 to 32 and 12 to 31.
grtz
Arnoud