Hi, I can not measure at this moment, but here are @patvdleer measurements, I believe they should be the same for me:
“From left to right, 14V+, GND, data?, 5V+”
Pinout I wrote in repository is the same.
1 → +12V (voltage should drop with load)
2 → GND
3 → AC_TX (data from AC to ESP)
4 → AC_RX (data from ESP to AC)
So your pinout should be:
- Pin 1: Red (top) → +12V
- Pin 2: White AC_TX (0V between GND)
- Pin 3: Green AC_RX (5V between GND and this pin, also like in PIN 4 in JST connector)
- Pin 4: Black (Bottom) → GND
Why there is 5V between Pin 4 and pin 3 (AX_RX), I can not answer technically, but i think that Pin 3 has a weak pull up and it stabilizes at 5V when no dongle is connected.
As I dont have unit with USB-type connector, I can not check pins myself, and there was a lot of disussions which pin is RX and witch is TX, but by comparing your given voltages with voltages with JST connector I see that USB pinout in repository is correct:
Pinout for USB style socket:
Pin 1 - 12v
Pin 2 - AC_TX - 16 pin
Pin 3 - AC_RX - 17 pin
Pin 4 - GND