Factory re-flash PLT-1B

If your Apollo PLT-1B becomes unresponsive and you've exhausted the other troubleshooting methods, you can re-flash the factory firmware. You'll put the PLT-1B in boot mode, flash it from the Apollo installer in your browser, and then set it up as a new device.

Before you start

• Do the re-flash in Chrome, Edge, or another Chromium-based browser.
• If your device has already been connected to Home Assistant, remove it from the ESPHome integration and the ESPHome Device Builder before continuing.

Remove the battery

The re-flash won't work properly if the battery is still supplying power to the PLT-1B. Remove the battery before you start, or as soon as you run into issues.

1. Put your PLT-1B in boot mode: hold down the boot button, then plug in the USB cable.

2. Open the Apollo PLT-1 installer. The PLT-1B uses the same page as the PLT-1.

3. Choose Battery Power, then click Connect & Install.

4. In the browser pop-up, select the open COM port (the PLT-1B's serial port, shown as USB JTAG/serial debug unit in the example below), then click Connect.

5. Click Install ApolloAutomation.PLT-1B.

6. Click INSTALL.

7. When you see Installation complete!, you're finished. Click Next, then close the browser window.

Your PLT-1B now has the factory firmware again.

Power cycle your device before doing anything else

Your PLT-1B is still in boot mode. Remove its power, then power it back on so it starts in normal mode.

8. Follow the getting started guide to set up your sensor as a new device.