AVR-Chat

Thhis may or may not help, but I had a similar problem before. I had  
an LED on my miso and mosi pins. When trying to program the chip in- 
system, the LEDs would flash and I don't think the voltage threshod  
was high enough to reprogram the chip, resulting in an obscure error.

My solution was to unplug the LEDs while programming. This was a  
prototyping board tho. Don't rewire till you get somemore input from  
other person



On Jan 25, 2009, at 12:29 AM, xolang1 <xolang1@yahoo.com> wrote:

> Hi Guys,
>
> I have a board with atmega128L and have sucessfully programmed the  
> chip using an AVRISP. However after adding some components on board,  
> I get "AVRISP Error entering programming mode" in codevision and a  
> similar message in AVRstudio.
>
> - I know that the AVRISP is working as I have been able to program  
> another circuit board w/ a mega64.
> - I tried using STK500 programmer with the mega128 board, but I get  
> the same error.
> - the programming pins are directly connected to the AVRISP port via  
> 600ohm ferrite beads.
> - I tried to insert a 12k pull up resistor on the reset pin, but  
> same reults
> - The components I have added before the board wont program are  
> several zener diodes across some GPIO's and 2 vibration sensors.
> - The last code I have programmed on the chip seemed to work. so i  
> could not be certain if it is the chip that is damaged.
> - changing the chip would be the last option as i have already changed
> before and the PCB is starting to be damged. I would really  
> appreaciate
> if u guys could enlighten me on how to proceed.
>
> thanks!
>
> Chris
>
> 


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