Updating device over USB cable, simplified method

Your Pow-device will regularly indicate that a new firmware version is available - and we always recommend running the last version.

Most of us upgrade without issues using the "one-click" method: Simply click the link that appears on the top bar when an upgrade is available:

However, this sometimes will fail, probably due to delays between the server and your computer.

The next best method is then to download the binary file *.bin for your microcontroller version from the Release section on Github. Then go to the status/info page, click  the button "Select firmware file for upgrade" - and follow the instructions.

However, we see that for a few users this also fails.

Well... there is a third option that can be used on all newer Pow-devices with ESP32 microcontroller: Upgrade over USB cable. In that way we avoid all potential issues due to Wi-Fi.

The easiest way to do this is by using a web based tool that exploits the Web Serial API. Unfortunately, not all browsers support this, so you might need to change to a compatible browser. We know that it works in Chrome browser on a PC, so that is what we recommend.

If you have not tinkered with flashing firmware on modules, you probably do not have the necessary driver on your computer. In that case, follow the instruction on this page to install the driver.

We are now ready, and the steps are the following:

1. Backup your current settings of your device by going to the Status/Info page and use the Download button on this tile:
2. Download and unzip the latest firmware for your device from the Release page, be sure to select the *.zip file, as you will need four files for this.
   If you are not sure which microcontroller you have, you can see it in the leftmost tile on the Status/Info page.
   
   In this case I would download  ams2mqtt-esp32s2-x.x.x.zip
3. Open this page in a Chrome browser window: https://esp.huhn.me/
4. Click the green "Connect" button. An empty window should open up.
5. On your Pow device: Press/hold AP, press/release RES, release AP
6. The port of the ESP should now show up like this:
   
7. Select it and press the blue "Connect" button.
8. A page will now be presented where you can enter the memory location and binary file for the four files that are needed for flashing an ESP32 device.
9. Select each of the four files from the downloaded ZIP file (that you have unzipped by now), and indicate the correct memory locations for each of them, like this:
   
10. Double check that the files and memory locations are set exactly as shown above.
11. Press the "PROGRAM" button.
12. You should now see the upload process to the device running in the "output" window at the bottom of the screen.
13. When finished, press the RES button on your Pow device.
14. Depending on whether the device still remembers previous settings, you may or may not see "boot" activity on the LED.
15. If no activity on the LED, or if the LED goes to
    1. Steady green on a Pow-U or Pow-P1 (which is blue and yellow at the same time)
    2. Steady yellow on a Pow-K
16. ... then you must search for the access point AMS2MQTT in your list of Wifi access points, and connect to it.
17. Open http://192.168.4.1/ to configure your device, just like you did when you first received the device.
18. When configuration is done and device has restarted: If necessary restore your settings from the backup file you created earlier, by using the "Select file..." button on the Status/Info page.

That's it. Congratulations, you have now upgraded your device over USB cable without needing to install Python, Esptool etc.