Firmware / Compatibility

Match the firmware to your exact board.

Normal MicroPython USB REPL and file transfers can work on many boards. Live source debugging is different: it requires a compatible debugger-enabled image, an available transport and hardware acceptance.

Official firmware repository ↗Start with USB REPL →

Public release status

Statuses below apply to the debugger firmware, not necessarily to ordinary serial scripting. Verified GitHub downloads are linked directly; successful automated compilation alone never means a board has been physically tested.

Board	Debugger firmware status	Connection guide	Next action
Raspberry Pi Pico W (RP2040)	Stable hardware-tested v2.6.0 Frozen debugger UF2 is a public release.	USB CDC0 = REPL and upload; USB CDC1 = debugger.	Download Pico W UF2 ↗
Raspberry Pi Pico 2 W (RP2350)	Existing live-debugger workflow hardware exercised New frozen UF2 remains a test-only candidate.	Follow the exact image's USB transport instructions; do not assume all Pico models use identical firmware.	Read test-build status ↗
Raspberry Pi Pico / Pico 2	Test-only candidates Per-board hardware acceptance is incomplete.	Serial and debugger configuration must match the selected candidate.	Review experimental files ↗
ESP32-S3	Preview, not stable Long-duration RTA and reset qualification remain outstanding.	Serial/JTAG USB = REPL/upload; native USB = debugger; typically two USB connections.	Read ESP32-S3 preview notes ↗
ESP32-C3 / ESP32-S2	No released dual-transport debugger firmware	Do not use ESP32-S3 binaries, nor assume a second native USB CDC is available.	Check future announcements ↗

Do not flash blindly. Back up your MicroPython files, verify the board and recovery procedure, and choose a verified image that explicitly matches the hardware. Never install ESP32-S3 firmware on ESP32-C3 or a Pico W image on Pico 2 W.

Which download should I choose?

Install the IDE

Use the approved VS Code Marketplace extension or the stable v2.6.0 VSIX. This is a PC extension, not board firmware.

Choose board firmware

The official firmware download matrix identifies approved vs preview releases. Match the board exactly.

Test safely

Confirm ordinary USB REPL before trying the separate debugger port. Only then check a breakpoint, locals, Continue, breakpoint removal and RTA On/Off.

Why two serial ports?

On the verified frozen Pico W image, the REPL/file channel is USB CDC0 and the debugger is USB CDC1. This allows normal serial access and debugging to use separate transports. Do not connect both functions to the same COM port.

ESP32-S3 differs: its preview uses the physical USB Serial/JTAG path for REPL/upload and a separate native USB debugger interface. Follow the preview guide before plugging in or flashing. Board-specific USB capabilities matter more than the name “ESP32”.

Pico W stable firmware release ↗Versioned UF2, version file and checksum manifest. Unreleased firmware candidates ↗Experimental binaries; test only, not an automatic upgrade. Debugger features and requirements →Breakpoints, stepping, variable inspection and trace meaning. Connection troubleshooting →Missing COM port, busy REPL, WebREPL and safe recovery.