The 20 cm Cable
A Raspberry Pi 5 with an OAK-D Pro depth camera bolted to it, recording material on a conveyor belt. First boot on the rig: hard crash within minutes. vcgencmd get_throttled returned 0x50000, the journal had fourteen Undervoltage detected! lines, the USB bus was dead — no camera, no tag reader — and the capture service was in a reset loop. Two days of bench work later the fix was a 20 cm cable. Getting there went through two hypotheses that were both partly right and individually wrong, and ended somewhere more useful than a culprit: an equation with about 0.3 V of headroom in it. ...