Flashing

Option A: Web flasher (recommended)

Visit themia.dev/flash in Chrome or Edge.

Plug in your device via USB
Select your board from the dropdown
Click Flash
Wait ~30 seconds for the firmware and filesystem to write
The device reboots automatically when done

No software installation required. Chrome or Edge only — Web Serial API isn't supported in Firefox or Safari.

Option B: PlatformIO

For building from source or flashing a custom build:

git clone https://github.com/paperclipsvinny/Meshtastic-Injection-Apparatus
cd Meshtastic-Injection-Apparatus/firmware

# install dependencies (first time only)
pio pkg install

# flash firmware
pio run -e heltec_wifi_lora_32_V3 -t upload

# flash web dashboard to device filesystem (required)
pio run -e heltec_wifi_lora_32_V3 -t uploadfs

Both commands are required. -t upload writes the firmware binary; -t uploadfs writes the web dashboard files to LittleFS. Missing the second step results in a blank page at http://192.168.4.1.

Option C: esptool directly

If you have pre-built binaries:

esptool.py --chip esp32s3 --port /dev/ttyACM0 --baud 460800 write_flash \
  0x0      bootloader.bin \
  0x8000   partitions.bin \
  0xe000   boot_app0.bin \
  0x10000  firmware.bin

Entering bootloader mode

Most ESP32-S3 boards with native USB auto-reset into download mode when esptool connects — no button press needed.

If it fails to connect, manually enter bootloader mode:

Hold the BOOT button (or bridge GPIO0 to GND on boards without a button)
Press and release RESET (or briefly bridge EN to GND)
Release BOOT
Run the flash command