Wire 2.5mm Subminiature plug to LANC protocol.

Hi, I’ve been playing with this for a couple of days and no idea what I’m doing.

I have a 2.5mm subminiature jack to receive commands from a LANC remote.

LANC protocol is here: The SONY LANC protocol

But I just want to start with the physical wiring.

The LANC uses the TRS connector like this

Tip: LANC (Serial).
Ring: 5…8V DC
Sleeve: Ground

What ports do I connect those to on my Arduino (mega). I have tried every possible combination I can think of.

I only need to RECEIVE data over serial, so have been using RX0 for the tip in most scenarios.

Thanks for any help.

It's first necessary to identify the voltage on the LANC serial. It may or may not be 5V. It is possible that it is +/-12V, as per RS232 serial. Those voltages are bad for Arduinos.

Then the LANC serial doesn't seem to be quite the same as normal serial. It does have start and stop bits, so perhaps it can be decoded by a regular UART. I'd like to have an oscilloscope to verify the signal.

Well the signal works when my remote is plugged into a camera.
If the spec is adhered to, voltage should be between 5 and 8V, though is there a way to actually measure which one?

Was assuming I'd plugged the voltage into the wrong pin. Wasn't sure whether I was meant to be supplying or receiving voltage (assumed supplying).

I've had it connected to the Power 5V and a digital pin set to high.

Okay took the plunge and plugged a $50 thousand camera into the board and am able to get actual numbers in the serial monitor.

5V plugged into digital pin set to high.
GND connected to GND.
Serial connected to RX0.

Will post in the programming section in regards to reading it if I have any problem.