: A 16 MHz crystal oscillator connected to the XTAL1 and XTAL2 pins, usually accompanied by two 22pF ceramic capacitors to GND.
: A 10kΩ pull-up resistor connected from the RESET pin to VCC to prevent accidental resets, often paired with a tactile push button to GND for manual resetting. Atmega Development Board Schematic
: An ICSP (In-Circuit Serial Programming) header consisting of MISO, MOSI, SCK, RESET, VCC, and GND for flashing firmware using an external programmer. : A 16 MHz crystal oscillator connected to