I recently got my TP Link WR703N ultra tiny router. Neat little thing.
But what makes this small electronic piece even more neater ?
Flashing custom firmware, of course !!
So long story shorts. I successfully bricked my device. Totally. Not even failsafe was working anymore.
So I had to get access to the console via serial port.
Uncool without a proper USB2Serial cable but I remembered to have a very old mobile data cable dug deep in my hardware
trash mystery chest.
The converting of the mobile cable failed because the PCB with the Prolific PL2303HX chip had no pin out printed on.
So suck it and see.
1. I made a close up shot of the board. Properly lit.
2. Got the datasheet for the chip (link) which is a PL-2303HX
3. Then I traced the circuits from the pins to the chip and I came up with this drawing:
From top to bottom:
8 / not assigned = ?
7 / yellow = ?
6 / not assigned = ?
5 / not assigned = ?
4 / black (thin cable) = RXD
3 / white = RTS_N
2 / not assigned = DTR_N
1 / blue = TXD
V 0 / red = 3.3 V
Hooking it up with the soldered serial port on the bricked device I managed to get serial console access using RealTerm.