Strange problem PIC16f877 with my JDM programmer

[sukumar]

jdm programmer

Hi,

I am using JDM programmer to program the PIC16f877. My connection is
5V power


VDD and VSS from external power supply

MCLR------- ----TxD
DATA(RB7)-----DTR + CTS
CLK(RB6)------- RTS
RB3-----GND


I have come across a strange problem.

winpic800 is not detecting my pic16f877a chip but Ic-Prog is programming as well.

if i place the positive lead of Multimeter to the MCLR pin winpic800 is detecting my chip.

So my questions is what is happening when i place the multimeter lead on MCLR pin of PIC16f877a and how the winpic800 is detecting that ic.

how to rectify it.

Regards,
M.sukumar

 

[wp100]

pic16f877 jdm programer

Seem to remember similar recent posts about this problem - either on this forum or Microchip or Et.

Have you got mclr pulled up with 10k.

Also worth putting RB3 / LV PGM to 0v - see the datasheet section - Low-Voltage ICSP Programming.

As mentioned in many forum posts you are pushing your luck with the JDM programmer - really suggest you look at the Pickit2 - worth every dollar - or if you want to - its quite easy to build a simple cut down, programmer only, version of it - as long as you can do the initial programming of the 18f2550 chip.

 

[sukumar]

power supply jdm programmer

Hi wp100,

Thanks for ur reply.
I have Pickit2 Programmer and i am using pickit2 for 1 year.
But this JDM is problematic in my older board but i am in a situation to rectify that problem.

I pulled up the MCLR pin with 1k resistor and I grounded the RB3/PGM pin as well.

Should I use 10 instead of 1K.

Regards,
M.Sukumar

 

[wp100]

rb3-pgm

hi ,

Yes 1k is way too low - 10k seems standard.

Think I would put a little 6 pin icsp connector for the PK2 on your old jdm dev board and bypass the jdm all together - why struggle !

 

[sukumar]

programing pic16f877a with pickit2

hi,

thanks i will do it and let u know the details.

Regards,
M.Sukumar

 

[mvs sarma]

make external power jdm programmer

hi,

thanks i will do it and let u know the details.

Regards,
M.Sukumar

Please upload the schematic of the JDM that you tried to use. Generally most JDMs use high voltage for programming. If so, there is no need to ground Pgm pin.

I would suggest you make one external powered Programmer like the design by DL4YHF
In case you are trying to program keepinyt in the target bord, without disconnecting other links, there might be some issues. you need to isolate connections on RB6, RB7,Mclr, and RB3
the best us is to use pickit2 compatible, like JUNEBUG from www.blueroomelectronics.com or PICKIT2 clone from www.mcuhobby.com .
perhaps you may purchase a simple PIC Cruizer programmer from www.united77.com

 

[pranam77]

pic16f877a programmer india

Hai Sukumar
Just go for this pocket size PICkit2 compatible PIC programmer with USB port support from United7 technologies. Just costs 1500/- for complete assembled tested kit with a programming board, programming software and manuals on CD icluding postage anywhere in India. For more info visit

**broken link removed**

Good luck.

 

[sukumar]

jdm programmer cts

Thanks for all,

Finally its working. I replaced 1K with 10K(thanks wp100) and Tied PGM to ground. Replaced Series resistor with MCLR pin with pullup resistor. And finally it is working.

Cruizer is very super i will try. Thanks 4 all

 

[pranam77]

pic16f877 high voltage programming

Hai Sukumar,
Thanks for the nice words abt the PIC Cruizer. In case you decide to go for it, and you are from Bangalore, It is availble in Bangalore at the below mentioned address:
M/s Sunrise Electronics,
No 67, Karthik plaza,
S.P. Raod, Bangalore-2
Ph: 080 41243027

 

[jasonlok]

hi, sukumar.
i wanna ask how are u settle the detection for pic16f877a, can u show some circuit layout on the modification that u have done?
thanks.