if I need to do something ?Board is a Feather ESP32What do I need to do and what happens if I don't do it ?
It means that you didn't provide enough information for anyone to help you. Is it April 1?You need to provide more information or you will get silly answers like this one.
What is attached to the pin in question?
I2C is designed to allow 2 or more devices to communicate over the same wires. There has to be a way to allow any device to transmit data without the others interfering. Open collector or open drain means a device can drive SDA or SCL low but not high. No device on an I2C can output high, only low. If no device can output high something else has to do that instead, which is what the pull up resistors do.
Does this mean that any device attached to the SDA pin is talking to it even though the sketch may have no intention to try and control(signal ?) it ?As an example, the Blink example sketch does not use the SDA pin but there might be an SDA device attached to it. Is there interaction between the pin and the processor ? ( I don't know who/what controls the SDA pin. Is there a separate chip on the Feather board that handles this ?)
I get the concept of master and slave. It sounds a bit like ethernet.
So, how do i tell the circuit (?), that the Arduino is the master?
Is this what the pull-up, pull-down resistor is supposed to do, indicate that a slave is present?
Given the need for a resistor it seems that the explanation should be more clear as to its value.