Rotocast Controller flash & diagnostics

Controls

Driver load while running (StallGuard, 0 = stall, 510 = no load — higher is more torque margin)

Hardware self-test

Checks every part of the controller in about a minute. It will ask you to press the button and turn the knob, jog each motor slowly for three seconds, and run the fan. Keep hands clear of the cages. The same test runs on the machine by holding the knob down while powering it on.

Update the firmware on a connected controller

For a controller that already runs. Takes about 20 seconds; saved speed and ratio are kept. For a blank board use New board instead.

Flash a brand-new board

A fresh board has nothing on it. One file installs both MicroPython and the controller firmware, and the board does the work itself — no software needed on this computer.

1. Download the firmware file
2. Hold the BOOTSEL button on the board and, while holding it, plug the USB cable into this computer. Let go. A drive called RPI-RP2 appears on the desktop or in the file manager.
3. Drag the downloaded .uf2 file onto the RPI-RP2 drive. It is a 4 MB file; the drive disappears by itself when it is done (about 25 seconds). Ignore any "disk not ejected properly" message — that is normal.
4. The board restarts: the LED lights red and the screen shows the ROTOCAST splash, then STOP. If the LED is red but the screen stays dark, the board still needs the two Rev 2 reworks (SW3 and Q3) — see the known hardware issues in the project README.
5. Click Connect at the top, pick the new port, and run the self-test.

The same file also works to update a controller that already runs the firmware: it resets the saved speed and ratio to defaults.

Console

Everything the controller prints, plus the telemetry it sends once a second. Type a command and press Enter — help lists them.