Firmware tester
Step 1 of 7Firmware tester
Run this right after flashing a firmware built by the Firmware Builder. It walks you through verifying drivers, endstops, stepper directions, homing direction, and the extruder – and produces a corrected configuration if anything is wired backwards.
Run this before Printer Setup.
Catch reversed motors, wrong endstop logic, or bad UART comms here, before kinematic calibration depends on them.
Connect to printer
Connect via USB serial. The port should appear after you click "Connect".
Configuration (optional)
Upload the JSON you exported from the Firmware Builder so the tester can compare expected wiring against what the printer reports, and produce a corrected file if anything is reversed. You can run the tests without it – the tester just won't be able to suggest a fix.
Diagnostics
Check that the firmware is alive, all six stepper drivers respond on UART, no endstops are stuck triggered, and both thermistors read sensible room-temperature values.
Show raw responses
Endstop walk-through
Step 1: with nothing pressing any endstop, the tester reads the initial state via M119 to check the firmware's logic-level (HIGH/LOW) configuration. Step 2: for each endstop in turn, manually press or trigger it; the tester confirms the state changes.
open.
If something reads TRIGGERED instead, the logic level (HIGH/LOW) in the firmware is most likely inverted and can be flipped in the corrected JSON.
Currently testing
–Read the initial state above, then click "Start walk-through".
Stepper direction tests
The tester sends a small relative move on each axis and asks whether it moved in the expected direction. A "no" flips the corresponding invert flag in the corrected configuration.
Currently testing
–Click "Start stepper test" to begin.
Homing direction
For each linear axis, tell the tester where the endstop is physically located. The tester compares your answer to the home direction in the uploaded JSON and flags any mismatch. No motor moves: a reversed home direction would otherwise drive the carriage into the frame.
B is centred-home (no MIN/MAX choice), so the homing-direction check doesn't apply. The endstop walk-through already verified the B microswitch in step 3.
Extruder
Confirm the extruder turns in the right direction, and optionally calibrate steps/mm by extruding a known length.
Extrusion direction test
Sends G91 then G1 E5 F100 to extrude 5 mm.
E-steps calibration (optional)
Mark the filament 120 mm from the extruder inlet. Click "Extrude 100mm" and measure how much filament was actually pulled in. The tester will compute corrected steps/mm.
Results
Summary of every test, plus a corrected configuration if the tester found anything reversed.
Test summary
Next steps
Everything passed. Continue to Printer Setup for kinematic calibration.