This is Yet Another AVR Fusebit Rescuer. It is able to restore fuses in bricked AVR microcontrollers using high voltage programming.
yaafr
One board rescues nearly every AVR in the classic line-up. Yaafr, "Yet Another AVR Fusebit Rescuer", pairs ZIF sockets from 40 down to 8-pin DIP with high-voltage parallel and serial programming. The chips it saves: locked and wrongly-fused ones that ordinary ISP tools refuse to touch.
On the board
- Five ZIF sockets, 40 down to 8-pin DIP.
- Two IDC headers: a fusebit-doctor compatible one, plus HVPP/HVSP expansion.
- AGND/AVCC switches. The datasheets argue about them.
- KiCad source and gerbers, plus an interactive BOM.
How a rescue runs
Drop the bricked AVR into a ZIF socket and power the board. An onboard microcontroller runs the programmer firmware, driving 12 V onto the chip's programming pins to force it into programming mode despite the lock bits. Flash it with Fusebit Doctor 2.11 or RescueAVR in FBD_MODE; whichever you pick sets the chip coverage. I leave the AGND/AVCC switches on. The datasheets flip-flop, but rescues work fine connected.