EA9500 v2 serial connection

Hello guys,

I got an ea9500 v2. The 4 serial pins are oriented differently on this board. With the top cover off and the ports in the back (away from you), the four pins for J201 are on the left side and halfway front to back.

The arrow points to the pin farthest back.

I can figure out which one is VCC and GND, but I don't have logic analyzer to figure out which one is TX and which one is RX. Does anyone know which pin is which?

I just go this from amazon and I don't want to risk connecting the TX pin of my serial adapter to the TX of the board and risk some electrical. I mean it's been open and they'll know I cracked it up from the hole poked on the sticker on the bottom.


Ended up figuring out. connected meter gnd to gnd and meter positive to pin 3 front to back and the voltage on that pin immediately started to fluctuate up and down, so TX. 2 pin front to back did not do that.

So facing router, thus putting J201 on the left, pins front to back are gnd, rx, tx, vcc

As long as you don't get GND/ Vcc wrong, there's no harm done trying both permutations for rx/ tx - either it works, or it doesn't.

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