Hello,

This question probably asked here many times:
P16Pro40 programmer:
works just fine with 16F628 and 12F675
Can't get it to work with 16F870 (tested 2 different chips)

Voltage 12.95V, no spikes.

Checked with 2 different software packages.

Any ideas?

Also, can a low voltage programming mode be used for 16F870 with P16PR40?

Thanks
Andy

 

The 16F870 probably requires Vpp40 rather than Vpp on the P16PRO40, have you programmed other large chips with it?.

 

Thanks for reply.

No I did not program any large chips, I have now only few 16F870 chips, rest of them small.

Yes it does require Vpp40 and I see different LED coming up and I see 12.95V on pin 1.
I checked spec on 16F87x and programming voltage is 13+/- .5V
It is little higer than voltage spec for 16F628 and 12F675 (12-13V)

Should I try to bump Vpp40 voltage to 13.5 or it may damage rest of chips?
Also I will try to replace transistor on Vpp40 line.

 

13.5V shouldn't cause any problems, but I've never had any problems with P16PRO40's like this. I've never had a 16F870 to try, but I've used 16F876 and 16F877 without any problems.

Did you build the programmer from a kit (with a PCB) or did you build it from scratch yourself?.

 

I built programmer using schematics and board from your site.
http://www.winpicprog.co.uk/download/p16pro.zip

I am designing and building electronic devices for over 30 years, but this is my first project with PICs

I will try to replace transistor and bump the voltage to see if it helps.