AVR / Briggs Firmware Programmer
The Firmware Programmer is a web-based engineering tool for flashing the controller firmware on AVR and Briggs & Stratton standby generators using an STM32 programmer connected via USB.
Who can use this tool: Engineering technicians and Pros with access to the EnergyTrak web app. The tool requires Google Chrome on Windows or macOS and is not available in the EnergyTrak mobile app.
Requirements
| Requirement | Details |
|---|---|
| Browser | Google Chrome (required — other browsers are not supported) |
| Platform | Windows or macOS |
| Windows Driver | STM32 DFU driver must be installed before connecting the USB cable on Windows |
| USB | STM32 programmer connected to the generator controller |
Opening the Programmer
- Open the EnergyTrak web app in Google Chrome and sign in.
- Navigate to Engineering Tools from the main menu.
- Tap Firmware Programmer under the AVR / Briggs Controller section.
Installing the Windows Driver (Windows Only)
Before connecting the USB cable on Windows, install the STM32 DFU driver:
- At the top of the Tool Overview section on Step 1, locate the Windows Driver card.
- Click Download Driver to download the driver installation package.
- Unzip the folder and follow the included installation guide.
The driver is required for Windows to detect the controller over USB. Without it, the programmer cannot connect even if the hardware is properly connected.
Programming Steps
The wizard uses 3 numbered steps followed by a completion screen.
Step 1: Select Generator Model
Enter the generator's serial number found on the nameplate, then tap Get Started.
The app automatically identifies the generator model and firmware version from the serial number.
No serial number available? Tap Don't have the generator serial number? to switch to Manual Model Selection:
- Type the power size (e.g.,
20kW) or model number (e.g.,040355) in the search field. - Select the correct model from the list.
Selecting an incorrect model can result in improper generator operation or hardware damage. Only use manual selection if you are certain of the model number.
Step 2: Generator Info and Bootloader Entry
Step 2 displays the generator details and step-by-step on-screen instructions for putting the controller into bootloader (DFU) mode before connecting the USB programmer.
The instructions shown depend on the controller type identified from Step 1 — AVR Gen1, AVR Gen2, or Standard Controller. Follow the instructions displayed in the app exactly as shown for your controller type.
Follow the button sequence precisely and in order. An incorrect sequence will leave the controller outside bootloader mode and the programmer will not be able to connect.
Flash Options
Two optional settings are available at the bottom of Step 2:
| Option | Description |
|---|---|
| Verbose Logging | Shows detailed debug output in the console during programming. Useful for troubleshooting. |
| Legacy Flash Mode | Manual override for older STM32 devices. Uses 1024B blocks with page-erase and auto-reboot. Auto-detected on connect — only enable if auto-detection fails. |
Step 3: Programming
After tapping Start Programming, the tool connects to the controller and flashes the firmware.
The screen shows:
- Status — current connection state (e.g., Connecting, Programming)
- Progress bars — separate Receive and Send indicators
- Debug console — real-time log output from the STM32 programmer
Wait for both progress bars to reach 100% before disconnecting the USB cable.
Completion Screen
When programming finishes successfully, the screen displays:
- Generator serial number, model number, customer name, manufacturing date
- Firmware version that was flashed
- Success! confirmation with the instruction to reconnect hardware
"The USB cable can now be disconnected. Replace the main fuse and reconnect the battery."
Disconnect the USB cable, reinstall the fuse, and reconnect the battery to return the generator to normal operation.
Tap Done to reset the wizard and program another generator.
Offline Mode (Beta)
Offline Mode lets you pre-download firmware files while online so the programmer can be used at sites without an active internet connection. This is an early-access feature — behavior may change.
Setting Up Offline Mode
Complete this while you still have internet access, before visiting the site.
- Open the Firmware Programmer and go to Step 1.
- Scroll down to the Offline Setup (Optional) section.
- Read the About Offline Mode notice.
- Toggle the Offline mode switch to enable it.
- Click Sync to download all available firmware files.
- Progress shows Syncing X of Y… during download.
- Once complete, the card shows the file count and expiration (e.g., "5 files cached, expiring in 14 days").
Cache TTL: Firmware files are cached for 14 days. After expiration, re-sync while online. The card shows remaining days until expiry.
Cache status icons:
| Icon | Color | Meaning |
|---|---|---|
| Cloud with checkmark | Green | Cache is fresh — ready to use offline |
| Cloud with checkmark | Yellow | Expiring within 7 days — consider re-syncing |
| Cloud off | Red | Cache expired — re-sync before going offline |
| Cloud downloading | Black | Sync in progress |
| Cloud off | Black | Not enabled or no files cached |
Cache Status Chip in the App Bar
When Offline Mode is enabled, a status chip appears in the top app bar showing the current cache state. Click it to see the file count, expiry, and a Re-sync button.
Using the Programmer While Offline
When internet connectivity is lost, the app redirects to the Offline Screen automatically.
- On the Offline Screen, tap Firmware Programmer under AVR / Briggs Controller.
- The programmer opens at Step 1.
Offline behavior on Step 1: Serial number lookup is unavailable. The app shows:
"You're offline. Serial number lookup is unavailable. Use manual model selection to continue."
Switch to Manual Model Selection and pick the generator model from the list. Steps 2 and 3 are identical to online operation.
The app returns to normal automatically when internet connectivity is restored.
Troubleshooting
Controller not detected on Windows
Install the STM32 DFU driver via the Download Driver button in the Tool Overview section on Step 1, then reconnect the USB cable.
Device not in DFU mode dialog
Disconnect the USB cable and repeat the bootloader entry sequence for your controller type. Follow the exact button order before reconnecting.
Cache expired / no firmware cached
Connect to the internet and click Re-sync in the cache card or from the app bar chip.
Serial number lookup unavailable
You are offline. Use Manual Model Selection to continue — see Using the Programmer While Offline.