pinout.vvzero.com/src/en/pin/pin-3.md

SDA (i2c Data) is one of the i2c pins on the Pi, [learn more about i2c](/pinout/i2c).

SDA includes a fixed, 1.8 kohms pull-up to 3.3v, which means this pin is not suitable for use as a general purpose IO where no pullup resistor is desired.
Added more info to i2c pins and overlay 2015-11-14 08:55:47 +08:00			`SDA (i2c Data) is one of the i2c pins on the Pi, [learn more about i2c](/pinout/i2c).`
Added more pin content 2015-03-25 08:29:41 +08:00
added unit for pull-up value 2015-11-15 05:00:41 +08:00			`SDA includes a fixed, 1.8 kohms pull-up to 3.3v, which means this pin is not suitable for use as a general purpose IO where no pullup resistor is desired.`