OTA Firmware Update

Once ESPGeiger is installed on a device, future updates are done over Wi-Fi from your browser. No USB cable, no toolchain, no command line.

If you’ve never flashed the device before, use the Web Installer instead - OTA only works on a device that’s already connected to your Wi-Fi and reachable on your network.

1. Download the firmware

Grab the latest .bin file for your board from the GitHub Releases page.

Every release includes one .bin per build variant. The filename tells you which one you need - it must match the variant you originally installed. For example:

esp8266_pulse.v1.2.3.bin - ESP8266 with a pulse-output tube
esp8266_serial.v1.2.3.bin - ESP8266 with a serial-output counter (GC10, MightyOhm, …)
espgeigerhw.v1.2.3.bin - ESPGeiger-HW board
espgeigerlog_pulse.v1.2.3.bin - ESPGeiger Log with a pulse tube
…etc

Not sure which one you’re running? The web portal shows the build name on the Info page as BUILD_ENV - match that.

⚠️ Flashing the wrong variant will either refuse to boot or boot with the wrong hardware assumptions (wrong pins, wrong counter type). If this happens, recover with the Web Installer over USB.

2. Open the device’s web portal

In a browser, go to your device’s address. Either:

http://<ip-address> - e.g. http://192.168.1.167 (find it in your router’s DHCP list), or
http://<hostname>.local - e.g. http://ESPGeiger-abcdef.local

From the main portal page, click the Update button. This takes you to the firmware upload page.

4. Choose the `.bin` file

Click Browse… and pick the .bin you downloaded in step 1.

5. Click Update

Click the Update button on the upload page. The device:

Shows “Update in progress…” on its OLED (if fitted)
Lights the activity LED
Stops all regular activity (MQTT publishes, WebAPI posts, serial output) to avoid interfering with the flash write
Receives the new firmware, writes it, verifies it, and reboots

Total time is typically 15–30 seconds depending on your Wi-Fi. Don’t close the browser tab until the upload bar finishes.

After the update

The device reboots into the new firmware. Wait about 10 seconds, the page should refresh. The version on the Info page should show the new release tag.

Your settings (Wi-Fi credentials, MQTT config, tube ratio, etc.) survive the update - only the firmware code is replaced.

If it fails

“Update failed” with a tiny bar - the device recovers automatically, you’ll still be able to reach the portal on the old firmware. Try again.
Device unreachable after update - usually the wrong .bin variant. See the warning in step 1. Recover with the Web Installer over USB.
Upload stalls partway - usually Wi-Fi instability. Move closer to the router or use a wired-closer AP, and retry.

Advanced: command-line OTA

If you prefer the CLI, espota.py (ships with the Arduino ESP core) does the same thing in one command:

python espota.py -i 192.168.1.167 -p 8266 -f esp8266_pulse.v1.2.3.bin