How to build a Pipo2 programmer for PIC16F877

Hi,
Does somebody have an experience with this programmer? I built it but it does not work!! It has a very simple schematic and i would like to build this programmer for 16F877.Why does not it work? How many voltage should i measure when programming, reading and idle position?

**broken link removed**

Analyzer. :?

pipo2 software

hi my frend

look at this link
a very simple programmer ''JDM''

**broken link removed**

**broken link removed**

pipo2 problem

Take a look at Microchips Programming Specifications for that chip ( **broken link removed** ). You can see that the programming voltage (high voltage mode) is specified between 12.5V and 13.5V at a rise time < 1us. So it's not a good idea to get the programming voltage from the serial port as it's not guaranteed that this port reaches 12.5V. But I don't think this is your problem. I've seen a lot of PICs entering the programming mode @ about 8V ...
Much more important is the very fast rise time (check it with a scope). Also be sure to tie RB3 (low voltage programming pin), OSC1 and OSC2 to ground during programming mode (read & write !).
Note that there is a difference in the programming algorithm of 16F877 and 16F877A (ref. to the migration specs https://www.microchip.com/download/lit/migrat/39591a.pdf). So if your software uses the wrong algorithm you're only able to read the preprogrammed device ID but any try to program the device will crash.


Good luck,
Mik

pipo2 software download

Hi my friend Analyzer

The problem with schematic i uploaded real one pipo2 schematic

look at schematic and you see the diffrence in the past i used this hardware with no problem

regards
Fragrance

pipo2 programmer

Hi fragrance,

Thank you very much for this upload.It is very diferent from my pipo2 link.Do you have a pcb draw for schematic? If not, i will draw it.Thank you.

Analyzer.

jdm programmer pipo2

Hi analyzer

I have no pcb for it i made it on strip board if you made pcb design please send me copy of the design

regards
Fragrance

pipo2 pcb

Hi,

I want a copy of the pcb layout too. Please don't forgot me

Thanx