Troubles with ATtiny85 fuses = 0xFF

[stephane]

Hi,

As said in the title, I'm unable to re-program my fuses.

Configuration :
- HV Rescue shield v2.1
- Sketch v212
- Arduino IDE v022
- Arduino UNO
- Win 7

I programmed the fuses on LF = 0xE2; HF = 0x5F, then I have to reprogram to 0xE2/0xDF if I want to be able to use the reset pin for ISP programming.

I tried once with the Rescue Shield, and now, it read my fuses on 0xFF/0xFF, and I can't do anything.
I've searched, and haven't found any solution on my configuration.

I paste you the serial communication :

Select mode:
1: ATmega (28-pin)
2: ATtiny2313
3: ATtiny (8-pin) / HVSP
Selected mode: ATtiny/HVSP
Insert target AVR and press button.

Existing fuse values:
LFUSE: FF
HFUSE: FF

Enter desired LFUSE hex value (ie. 0x62): E2
Enter desired HFUSE hex value (ie. 0xDF): DF
Burning fuses...

Read LFUSE: FF
Read HFUSE: FF
Burn complete.

It is now safe to remove the target AVR.

Insert target AVR and press button.

What informations can I give you to help find the problem ?

[mightyohm]

Did you insert or remove the ATtiny85 while the red (BURN) light was on? I have seen this happen before when I accidentally removed the part during the rescue operation.

If I understand your post correctly, the initial read succeeded, with reads returning 0xFF only after you tried burning the fuses once. Is that correct?

Can you measure the voltage on the 12V_SW test pin with respect to ground, while the BURN LED is on? It should be about 12V.

[mightyohm]

Today I confirmed that my Rescue Shield and ATtiny85 do not exhibit this problem with the fuse values shown above.

Please respond with some more information about your problem so I can help you troubleshoot further.