---
name: flashing
description: How to compile and flash sketches to the Arduino Uno Q MCU over SWD using the uno_q_flash tool. Load this whenever the user asks to upload, flash, run, program, or build a sketch on the Uno Q.
---

# Flashing the Uno Q MCU

Use the **`uno_q_flash`** tool. The MPU programs the MCU's flash directly over
SWD (bit-banged GPIO via OpenOCD `linuxgpiod`) — no USB cable, no SSH.

## How to use it

- `action = "upload"` + `code` (full `.ino`) — compile then flash. The sketch
  runs immediately (`reset run`). **This is what you call to make a sketch run.**
- `action = "compile"` + `code` — verify it builds, don't flash.
- `action = "detect"` — list boards.

When the user asks to upload/flash/run a sketch, CALL the tool with
`action="upload"`. Do not explain the steps in prose. Always provide the
complete sketch (`setup()` + `loop()`).

## Under the hood (for context, not for the user)

- Compile: `arduino-cli compile --fqbn arduino:zephyr:unoq --export-binaries`.
- Flash: OpenOCD writes the image to the bank-2 partition at **`0x8100000`**
  (the correct sketch address; `0x80F0000` is reserved and never executes).
- Requires on-device `arduino-cli` and `/opt/openocd` with `openocd_gpiod.cfg`.

## If it fails

- Compile errors come back in the tool result — fix the sketch and retry.
- "OpenOCD not found" → the Zephyr core's OpenOCD isn't installed at `/opt/openocd`.
- Remember the 3.3 V rule and that PWM is only D3/D5/D6/D9/D10/D11.