AVR-Chat

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

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
>
> 


[Non-text portions of this message have been removed]

If you plan to use the ISP and external circuits on the programming 
pins, Chris, you should always put a resistor in series with the 
external circuits so they don't load down the ISP signals ... not to 
mention possible unintentional damage to your external system in some 
manner.  An alternative would be to use a multiplexer similar to a 
CD4066 or a CD4052.  Jumper select the source when programming and 
you're good to go.


REB


xolang1 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
>

thanks guys, but...
 
As I am using mega128, the the prog pins are shared with UART on PE0 and PE1 whcih are also conencted to a max202 chip. I have no prolem programing the chip even with this set up in this board before. So i assume it should not be aproblem in this case.
 
another other suggestion/input?
 
i will try to disconnect the Vcc of the max202 and see
 
thanks 
-chris
 


--- On Sun, 1/25/09, Roy E. Burrage <RBurrage@bellsouth.net> wrote:

From: Roy E. Burrage <RBurrage@bellsouth.net>
Subject: Re: [AVR-Chat] AVRISP programming
To: AVR-Chat@yahoogroups.com
Date: Sunday, January 25, 2009, 4:58 PM






If you plan to use the ISP and external circuits on the programming 
pins, Chris, you should always put a resistor in series with the 
external circuits so they don't load down the ISP signals ... not to 
mention possible unintentional damage to your external system in some 
manner. An alternative would be to use a multiplexer similar to a 
CD4066 or a CD4052. Jumper select the source when programming and 
you're good to go.

REB

xolang1 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
>
 














      

[Non-text portions of this message have been removed]

At 02:36 AM 26/01/2009, you wrote:
>i will try to disconnect the Vcc of the max202 and see

DONT!!!! You are only making things worse as the whole
chip will try to power up from the TX pin and the programmer.

You have most likely BLOWN up all of the programmers used
as they will be fighting with the output of the MAX 202.

If nothing has blown up then:

Either use a jumper to isolate the RX pin from the MAX202 during
program or use a 1K resistor (minimum) between the pin RX of the
M128  and the output of the MAX202.

Throw away ANYTHING that is between the programmer and the programming
pins of the chip.

Regards

John Samperi

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