AVR Programmer problem

[RollingEEE]

Hi,

I made the Peter Fleury's programmer for avr on a vero board. Pony prog does not recognise it. And Asim ISP can read with it but cannot write any thing. Can any one please tell me what's wrong

 

[nandhu015]

have you checked the lock bits

Normally if you can read from a chip, then there will be no problem with writing.

(I think your programmer is fine, the problem is elsewhere)

Nandhu

 

[RollingEEE]

well, technically, it can write, but if auto verify is kept enabled, then it gives verify error. And even if I write a program (with auto verify turned off) then the written program somehow automatically changes, the hex code is completely different and garbage when it is read again.

 

[banjo]

The 100K pull-up resistor on the MISO line seems a little large. I would reduce this value by about 1/2. Double-check all your solder joints and connections. Does the 74125 chip have a good, clean source of +5V? Are the control enables on pins 1,4,10 and 13 hooked up in the proper order?

I have never used this version of programmer. I have programmed many parts using the simpler version that just uses diodes and resistors. The AVR DUDE programmer that is bundled with WINAVR supports many of those.

With the simpler programmers, you have to make sure that the parallel port is set to the correct mode in BIOS. With Peter's programmer it should not matter. However, I would still try the other settings within BIOS just to be sure. Usually, there are three or four different modes. Also, you have to make sure that some other software like a printer driver is not grabbing some of your data. Make sure nothing else is attempting to use that port.

 

[eehero]

just do the following to have a good AVR programmer:

1- build the following schematic on:
http://www.lancos.com/e2p/avrisp-siprog.gif
2- build the adapter u need from this link:
http://www.lancos.com/siprogsch.html

it is pony prgrammer, i had build it and it is so good, try it.

 

[RollingEEE]

You wouldn't believe it. The programmer is fine. Only I changed the PC and it worked. I think my parallel port wasn't working.

 

[nandhu015]

Have you checked the parallel port setting EPP or ECP

Nandhu