Keyboard shortcuts

Press ← or → to navigate between chapters

Press S or / to search in the book

Press ? to show this help

Press Esc to hide this help

USB & OS Notes

The Pico de Gallo firmware uses a generic WinUSB-compatible descriptor, so most operating systems pick it up without a custom driver. The notes below cover the cases where you need to nudge the OS.

Linux

Out-of-the-box, libusb (and therefore nusb) requires root to open arbitrary USB devices. To let your regular user account talk to Pico de Gallo, drop a udev rule:

# /etc/udev/rules.d/99-pico-de-gallo.rules
SUBSYSTEM=="usb", ATTR{idVendor}=="045e", ATTR{idProduct}=="ffff", MODE="0666"

Then reload udev:

$ sudo udevadm control --reload-rules
$ sudo udevadm trigger

Unplug and replug the device. gallo version should now work without sudo.

Note

The VID 045e (Microsoft) and PID ffff are placeholders used by the firmware — Microsoft’s vendor block reserves ffff for prototyping. They are not registered for Pico de Gallo and should not be considered stable across firmware versions.

Windows

The firmware advertises a Microsoft OS 2.0 descriptor that tells Windows to bind the WinUSB driver automatically. The first time you plug in a Pico de Gallo, you may see a brief “installing device” notification — that’s normal. After that, gallo works without any extra setup.

If for some reason WinUSB doesn’t bind (e.g., a stale Zadig override, or driver-signing policy on a corporate machine), use Zadig to manually install the WinUSB driver against the Pico de Gallo interface.

macOS

No extra setup. macOS picks the device up automatically.

If gallo list returns nothing, check System Information → USB and confirm the device enumerates. If it shows up there but gallo can’t find it, you might have a code-signing issue with a locally-built gallo binary — try the pre-built release artifact.

Troubleshooting

  • gallo: device not found — Is the device plugged in? Did you flash firmware? Try gallo list.
  • Permission denied on Linux — udev rule missing or not reloaded. See above.
  • gallo version succeeds but gallo i2c scan hangs — the bus has no pull-ups, or your peripheral is clock-stretching forever. Add 4.7 kΩ pull-ups (v1.0 boards lack them on-board).
  • Device disappears after a write — likely a brown-out from trying to source too much current through the on-board 3.3 V rail. Power the peripheral externally.

See also: Troubleshooting for the full list.