How does open drain io act as bidirectional
The Line is read through a high impedance input. The line is controlled by the internal n-channel mosfet and the pull-up resistor. By turning off the mosfet, it releases the line so it is a passive input. When it turns on the fet, it tries to force the line low, but it still reads the input to check if the line is logic low or not.







simulate this circuit &ndash; Schematic created using CircuitLab