2MQTT-Flasher

2MQTT-Flasher is a desktop flasher for ESP8266 and ESP32 devices with a focus on keeping the workflow simple for end users.

The application is built around a GUI and is intended for typical 2MQTT use cases:

• flash a local .bin firmware file
• load current releases from all *2MQTT projects
• auto-detect serial ports and ESP devices
• show live serial logs after flashing
• display chip information

The actual flashing process uses Espressif's esptool under the hood.

Features

• Local firmware mode for .bin files in the program directory or a manually selected firmware file
• Release firmware mode that loads current Flash2MQTT releases directly from release.json
• split release selection into Repo Version and Variant
• automatic serial port scan
• chip information view
• serial log viewer
• default flash speed 921600 for faster flashing, fallback to 115200 for unsupported ESP chips
• compact GUI with only the relevant options exposed

GUI Overview

Main application window:

Features:

2MQTT-Flasher_2.mp4

Firmware Sources

Local

In Local mode, the program looks for .bin files in the program directory. If no files are found, the firmware selection shows:

no local files in program directory

You can still use the Browse button to select a firmware file manually.

Release

In Release mode, the program downloads the current firmware index from all *2MQTT projects:

The selection is split into two steps:

1. choose Repo Version
2. choose the matching Variant

This keeps the release list easier to navigate when multiple device variants exist for the same firmware family.

Typical Workflow

1. Connect your ESP device by USB.
2. Start 2MQTT-Flasher.
3. Wait for auto-detection or choose the correct serial port manually.
4. Select your firmware source: Local or Release.
5. Choose the firmware.
6. Click Flash ESP.
7. After flashing, use View Logs or let the application reconnect automatically to the serial log.

Installation

Prebuilt Application

Use the release package for your operating system and start the application directly.

Linux Notes

On many Linux systems, access to serial ports requires membership in the dialout group:

sudo usermod -a -G dialout $(whoami)

After that, log out and back in again.

macOS Notes

Depending on the USB serial adapter in use, an additional driver may be required.

Silicon Labs VCP information:

https://www.silabs.com/community/interface/forum.topic.html/vcp_driver_for_macosbigsur110x-krlP

Silicon Labs VCP download:

https://www.silabs.com/documents/public/software/Mac_OSX_VCP_Driver.zip

Troubleshooting

No serial port available

• check USB cable quality
• check USB driver installation
• reconnect the device
• on Linux, verify dialout permissions

Port is busy

Close other serial tools such as:

• Arduino IDE serial monitor
• PlatformIO monitor
• other flasher tools

Antivirus warning on packaged binaries

PyInstaller-based desktop apps can trigger false positives on some antivirus products.