Arduino UNO I2C
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PINS
On all Arduinos UNO
- A4 = SDA
- A5 = SCL
On Arduino UNO R3
- A4 = SDA AREF - 1 pin (up right corner)
- A5 = SCL AREF - 2 pins (up right corner)
CODE
BUS
Pull-up resistors between SDA & VCC and between SCL & VCC ≈ 4.7kΩ (depends on bus capacitance - length - and desired speed).