Arduino Doorbell

These are mostly notes for myself so I don't forget how did it work.

QH-09BCE

• -GND is connected directly to GND on Uno
• 3V is connected to 3.3V via breadboard; can be directly but we need +3V for Ethernet adapter
• LED+ goes to A3 (can be any analogue pin)

ENC28J60

• 3.3V and GND are connected to the breadboard and directly second GND respectively
• SO pin 12
• SI pin 11
• SCK pin 13
• CS pin 8