PICPgm LVISP Programmer Help!

[sk_008]

picpgm

Hello everyone!
I've a problem regarding the PICPgm programmer. I've built the LVISP Programmer. PICPgm detects the programmer but not the PIC. Ive tried two pics uptil now and they are PIC18f4550 and PIC16f877 but none could be detected. I've checked the connections again and there seems to be no problem. One thing that i've also done is that I've connected a 33pf cap with a 100 ohm res in series to gnd with the PGD line and a 33pf to gnd with PGC line but this also didn't help.
The RB5 pin is also connected to gnd via a 1K res as mentioned in the circuit. What could be the possible fault? please help me out!
Thanks in advance

 

[mvs sarma]

picpgm lvisp

Hello everyone!
I've a problem regarding the PICPgm programmer. I've built the LVISP Programmer. PICPgm detects the programmer but not the PIC. Ive tried two pics uptil now and they are PIC18f4550 and PIC16f877 but none could be detected. I've checked the connections again and there seems to be no problem. One thing that i've also done is that I've connected a 33pf cap with a 100 ohm res in series to gnd with the PGD line and a 33pf to gnd with PGC line but this also didn't help.
The RB5 pin is also connected to gnd via a 1K res as mentioned in the circuit. What could be the possible fault? please help me out!
Thanks in advance

Perhaps you need to loop both Vdd pins and connect to 5V and both Vss pins looped and connected to Gnd. the specific pins can be checked wrt the chip

 

[sk_008]

no pic detected picpgm

Thanks for the reply mvs sarma!
I've done this too but the problem remained the same.

 

[mvs sarma]

picpgm programmmer

Perhaps we are wasting time with these non standard programmers.
You may better settle with Pickit2 ot a clone.
Your time would be saved and you could concentrate on development of software.
BTW, please ensure that there is no crystal or caps on the PIC under program
Also, be sure that there is no other load on RB6, RB7 RB3(5) that are used for programming.
total capacitors across power line could be tter be removed for the time of programming , to be introduced later.

 

[sk_008]

picpgm problem

I think you're right its really a waste of time coz 2 or 3 months ago i made a programmer for pic16f877 it worked correctly for 2 or 3 times and then i couldnt understand what happened to it.
Thanks for your suggestions I'll definitely look for those things and then inform about what happened

 

[picpgm]

Hi,
have you checked the following points?
1) Are all Vss and Vdd pins of the PIC conntected to the corresponging Programmer pins?
2) Is the 74LS05 connected to the power supply, i.e. pin 14 = +5v, pin 7 = GND?
3) Have you used the hardware test dialog of PICPgm and measured the corresponding voltage on the pins according to the pin state set in the hardware test dialog? E.g. does MCLR pin toggle if the corresponding checkbox in the dialog is toggled?

 

[picpgm]

Hi!

I have summarized some hints which might help to get your programmer working at **broken link removed**.

Regards,
Christian