$ ./avrdude -c xplainedmini_updi -U fuses:r:fuses.hex:i -p t817 avrdude: AVR device initialized and ready to accept instructions Reading | | 0% 0.00s avrdude: Device is locked! Chip erase required to unlock. avr_read(): error reading address 0x0000 read operation failed for memory "signature" avrdude: error reading signature data for part "ATtiny817", rc=-68 avrdude: Received FamilyID: "megaAVR" avrdude: Expected FamilyID: "tinyAVR" Double check chip, or use -F to override this check. avrdude done. Thank you. $ ./avrdude -c xplainedmini_updi -U fuses:r:fuses.hex:i -p m4808 avrdude: AVR device initialized and ready to accept instructions Reading | | 0% 0.00s avrdude: Device is locked! Chip erase required to unlock. avr_read(): error reading address 0x0000 read operation failed for memory "signature" avrdude: error reading signature data for part "ATmega4808", rc=-68 avrdude: Received FamilyID: "megaAVR" avrdude: error reading signature data, rc=-68 avrdude done. Thank you. $ ./avrdude -c xplainedmini_updi -e -U fuses:r:fuses.hex:i -p m4808 avrdude: AVR device initialized and ready to accept instructions Reading | | 0% 0.00s avrdude: Device is locked! Chip erase required to unlock. avr_read(): error reading address 0x0000 read operation failed for memory "signature" avrdude: error reading signature data for part "ATmega4808", rc=-68 avrdude: Received FamilyID: "megaAVR" avrdude: erasing chip Reading | ################################################## | 100% 0.01s avrdude: Device signature = 0x1e9651 (probably m4809) avrdude: Expected signature for ATmega4808 is 1E 96 50 Double check chip, or use -F to override this check. avrdude done. Thank you. $ ./avrdude -c xplainedmini_updi -e -U fuses:r:fuses.hex:i -p m4809 avrdude: AVR device initialized and ready to accept instructions Reading | ################################################## | 100% 0.04s avrdude: Device signature = 0x1e9651 (probably m4809) avrdude: erasing chip avrdude: reading fuses memory: Reading | ################################################## | 100% 1.96s avrdude: writing output file "fuses.hex" avrdude: safemode: Fuses OK (E:FF, H:FF, L:FF) avrdude done. Thank you. $