16MHz ceramic resonator connected between chip pins 33 and 34, with resonator's ground pin connected to chip's GND.LED x 1 and 1k current limiting resistor x 1 connected between D/13 (chip pin 26) and GND, this is same as the Arduino Mega 'L' LED, to be us as indicator to test prototype.10k pull-up resistor x 1 connected between RESET (chip pin 30) and VCC/AVCC.0.1uF bypass capacitor x 3, connected in parallel to 3 of the VCC/AVCC and GND pairs (chip pins ).
ATmega2560 chip from an Arduino Mega2560 clone (functional chip and bootloader) removed with a hot-air gun, soldered on to a TQFP100 breakout PCB.A prototype board was made as proof of concept, the components, placements, and connections are:
