mcu-tinkering-lab (laurigates) errors

12 recurring problems engineers report in mcu-tinkering-lab (laurigates), ranked by impact.

#36 by errors trackedFirmwareECADMCAD

Recurring mcu-tinkering-lab (laurigates) errors, by impact

  1. 1A robocar repo's docs said the camera was an OV2640 (it is an OV3660), provisioning was BLE (it is serial over USB), the planner ran at about 1 Hz (it is 15 s and boots dormant), and an I2C mux channel was reserved (an MCP23017 sits there). All three CI guards were green and correct, and every error was on the hand-typed side of the generated/hand-written boundary, which nothing checks.Firmware · Agent failure · 1 report74
  2. 2An earlier commit put socket J3 where the GY-521 module fits only face down, which inverts X and Z for the firmware. Nothing compared the layout with the firmware's IMU mount, so the problem was found on the delivered boards.ECAD · Agent failure · 1 report74
  3. 3For the balancebot carrier board, the schematic nets were typed by hand into the KiCad MCP server's schematic tool, rebuilt three times, and the author says one of those passes is where the XT30 polarity error came in. The next board has 39 parts and nets, about five times as many, and copying the scripts would copy both restatements, which would drift.ECAD · Agent failure · 1 report74
  4. 4Same lab, same board. JLCPCB fabricated an old balancebot upload that was still in the cart. Nothing on the board or in the file name identified the commit, and the hand-off CSV recorded the commit of the zip on disk rather than the file in the cart.ECAD · Agent failure · 1 report74
  5. 5A TCA9548A clone module has the same pin order as the Adafruit board but rows 17.78 mm apart instead of 15.24 mm. Issue #905 said the clone was one pitch narrower. The photo and caliper said one pitch wider, and "the footprint follows the measurement." The fix doubles the header pads with the same pad numbers so the netlist doesn't change.ECAD · Agent failure · 1 report66
  6. 6Camera and logger headers still named the ESP32-CAM from a removed dual-board design. Stale references to hardware that no longer exists in the design.Firmware · Agent failure · 1 report66
  7. 7In #1085, three headers got an estimated height for a plugged lead, the enclosure test for look-alike parts failed on main, and no workflow ran that suite yet.ECAD · Agent failure · 1 report66
  8. 8Removing a hand-drawn module outline also removed the pin-1 mark. The GY-521 fits its socket three ways wrong, including the face-down fit that caused the bug in finding 1. New gate: every socket with a wrong fit needs a tagged silkscreen mark within 4 mm.ECAD · Agent failure · 1 report66
  9. 9The 'SVGs are up to date' gate used git diff, which ignores untracked files, so a PR that added a circuit and forgot git add on its SVG passed. Images from deleted circuits were never flagged either.ECAD · Agent failure · 1 report66
  10. 10The generated cases for robocar-unified all report 'CANNOT ASSEMBLE ... BLOCKED (the seated pose already clashes),' with 195.2 mm³ of clash on the main tray and 72.1 mm³ on the head. The clash sits at PCB thickness along the walls facing the panel saw lines, and the author's hunch is that the board mesh covers the whole panel instead of its own piece.MCAD · Agent failure · 1 report66
  11. 11The socket footprint uses the measured board size, but two hole offsets are assumptions, 1.61 mm and 1.27 mm. The pre-order review measured 1.2 mm between the module edge and a connector housing, so a row about 1 mm off-centre closes that gap. The Y axis in the docs is derived from X and Z, not read off the module. Fixing it means measuring, editing a TOML, regenerating, rerunning two checks and committing a stamp.ECAD · Agent failure · 1 report66
  12. 12WIRING.md and the schematic were corrected in September to put TB6612FNG and PCA9685 VCC on 3.3 V, but the printed build guide still said VM/VCC to 5 V, which raises the input-high threshold to 3.5 V, above what the 3.3 V XIAO drives. The PR also caught Typst eating a semicolon so the PDF printed the wrong STBY line.ECAD · Agent failure · 1 report66

How it fails

  1. Agent failure12

Sourced from public community reports. Costs and delays on individual entries are modeled estimates, not measurements.