My AVRISP mkII decided to refuse cooperation with avrdude, preventing me from using it with Arduino IDE any more. Meanwhile I don’t really have an Arduino in spare to use for any generic programming.
So I designed this, M184v1, an Arduino Uno equivalent permanently connected as Arduino as ISP, and added a MOSFET level shifter just for the fun of it. (and the dual-MOSFET construct now allows this level shifter being used to shift the levels both ways.)
Also added is a button and an AT24C512 EEPROM chip so I can store even the largest Flash+EEPROM image (for ATmega2560) and implement that “press to program” feature I lifted from PICkit.
Core components: MCU: Atmel ATmega328P-AU, USB to Serial: WCH CH340G: PTP Storage: Atmel AT24C512, level shifters: 2N7002.