While the ANAVI Miracle Emitter is compatible with the popular open source WLED firmware, it comes preloaded with our own open source firmware, developed as an Arduino sketch. For one reason or another you may need to change or re-flash it. In this guide, you will learn how to use Esptool to flash a precompiled binary version of this default firmware onto the ANAVI Miracle Emitter. These instructions are also applicable to other devices powered by the Espressif ESP32-C3 Wi-Fi and Bluetooth Low Energy (BLE) system-on-chip.

Esptool is a powerful command-line utility developed by Espressif, designed for flashing firmware to their family of chips, including the ESP8266, ESP32, and RISC-V-based variants like the ESP32-C3 on the ANAVI Miracle Emitter. Written in Python, Esptool allows users to read, write, and erase flash memory, offering fine-grained control over the process. It supports custom baud rates, memory addresses, and chip selection, making it suitable for tasks like installing bootloaders or flashing firmware binaries. Cross-platform and open source, Esptool runs on Linux, Windows, and macOS. The source code is available under the GPLv2 license on GitHub. It is an essential tool for developers who need direct, low-level access to ESP chip flashing.

Installing Esptool on Ubuntu

Esptool runs on MS Windows, macOS and various Linux distributions. In this tutorial we will focus on Ubuntu, one of the more popular Linux distributions. Execute the steps below to install Esptool on Ubuntu 2024.04 LTS:

sudo apt update
sudo apt install python3 pipx -y
pipx install esptool
pipx ensurepath

Check that Esptool is properly installed by running the command:

esptool version

Flashing Firmware and Bootloader

Download the precompiled firmware from GitHub, connect your board via USB-C, and flash both the bootloader and firmware using the following command:

esptool --chip esp32c3 --port /dev/ttyACM0 --baud 460800 write_flash 0x0 path/to/anavi-miracle-emitter-sw.ino.merged.bin

Flashing Firmware Only

To preserve the bootloader and flash just the firmware execute:

esptool --chip esp32c3 --port /dev/ttyACM0 --baud 460800 write_flash 0x10000 path/to/anavi-miracle-emitter-sw.ino.bin

Please note the difference in the filename and address because the command above flashes the firmware only.

ANAVI Miracle Emitter is an open-source device designed to control 5 V addressable LED strips like NeoPixels. Successfully funded on Crowd Supply as of May 29, 2025, all kits were delivered to the Crowd Supply warehouse by the end of June and subsequently shipped to backers. If you haven’t yet, consider ordering an ANAVI Miracle Emitter to power up your next awesome LED project!