AVR HV Rescue Shield 2

[Jeff Keyzer] has a new version of the HV Rescue Shield available. This tool allows you to use an Arduino to reset the fuse bits on AVR microcontrollers. This is necessary if you make a mistake and disable the reset pin, or choose the incorrect clock settings (this will probably happen to you at some point). In order to bring the chip back to life you’ll need to use High Voltage Programming. The last version of the shield only worked with High Voltage Parallel Programming (HVPP) but this rendition can also use High Voltage Serial Programming (HVSP) for 8-pin chips that don’t have enough inputs for parallel communications.

As we talked about in our AVR Programming Tutorials this is no replacement for a high-end programmer like the STK500 or an AVR Dragon, but if you already have an Arduino¬†a kit will only cost you $20 (or you can etch and build it yourself). We would have liked to see a breakout header for the HVP signals for off-board use. The absence of a breakout header doesn’t preclude this, but since you need the on board boost converter for the 12V signals, and because this shield can’t be used with a breadboard due to pin spacing, it’s hard to patch into signals for non-DIP use. We also think some clever firmware hacking and this could be used for HV programming, like we needed for that LED light bulb.


  1. So wait, if you don’t have $25 for a USB STK500 2.0 knockoff, you can spend $20 on a shield that does virtually nothing in comparison? And I say unto thee, feh.

  2. BiOzZ says:

    i have never set a fuse wrong but there is a first for everything (knowing my clumsy ass) but do they sell these things as commercial standalone products?

  3. Brent says:

    You’ve run another project like this before:


    I still don’t see the point when the Dragon is $49 and gives you in-circuit debugging. If you can afford to put this kind of hack on a custom PCB, you can afford a real in-circuit programmer/debugger.

  4. ss says:

    Unless a firmware update in the last year fixes it, the dragon can’t do HVPP for the 328p: http://www.avrfreaks.net/index.php?name=PNphpBB2&file=viewtopic&t=70678

  5. vtl says:

    $20 for a board to rescue a chip thats worth considerably less than that? Looks like youd be better off just breadboarding this. Why would you want to go thru the pain of ething a pcb for this? Surely you should spend that effort not programming it wrong in the first place. Or have i missed something?

  6. rsbohn says:

    Perhaps it’s the Lazarus Effect. Restoring life to a bricked chip gives you an awesome feeling. Yeah, you could buy a Dragon or throw this together on a breadboard, but a quick plug-in solution for that Arduino you already own has its place.

  7. zool says:

    maybe you were doing a small production and things went wrong, this could help
    or maybe you could get a ton of dissabled avrs for cheap and just restore them

    i like his dc-dc converter there
    jeff’s pretty cool

  8. Brent says:

    OK, I’m dense. The appeal of these things is that one can reset fuses without leaving arduino-land.

    BTW, where’s the $25 USB STK500 clone?

  9. pwnr says:

    Guess its a good thing I live in the silicon desert…got my stk500 for $2.00 at goodwill…still trying to find time to play with it to see if it works, but it powered up!

  10. MoJo says:

    Build one on stripboard without the Arduino: http://denki.world3.net/avr_rescue.html

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