Using the Web Tool for EmonTx4/5 configuration

Following on from the topic
EmonTx5 Serial Web Connection

Note: The hardware of the emonTx4 is basically the same as the emonTx5. Although I don’t have an emonTx5 to test this, the following should be applicable (I hope).

I had got to the stage where I could use the web tool to connect to to my emonTx4 but I got an error saying my emonTx4 firmware was too old. I could however use the console box to send configuration commands.


I have now upgraded my emonTx4 firmware to the latest version (1.6.2).
Note that if you do this, the default configuration will be loaded back into the emonTx4. If you have changed the default configuration, e.g. the node ID (like me!) , you will need to do the change again, after the firmware update.

When I ran the web tool after the update, it worked.


To get the ‘save changes’ button to appear, you need to enter something (node ID in my case) and press return. To send the change to the emonTx4, press the ‘save changes’ button.

There are reports of problems with getting the web tool to work. There seem to be two factors involved:

  1. The USB-A to USB-C cable. I have 5 different cables, and one didn’t work; I found it was not wired to the USB-C standard.
  2. The combination of the computer operating system and the browser used. The browser has to be web-serial compatible. I am using openSUSE Tumbleweed Linux with the Chromium browser, but others have had success with different combinations. I think on Linux the named user has to be a member of the dialout group to be able to access the USB virtual serial port. I haven’t tried windows.

Can you clarify where that came from? According to the Github I’m looking at, the “latest” 6-channel version is 2.1.0, and the 12-channel version is 1.2.0.
(GitHub - openenergymonitor/avrdb_firmware: EmonTx4, EmonPi2 & EmonTx5 combined firmware)

I too don’t have an emonTx5, but my understanding is electrically and code-wise, it’s identical to the emonTx4. The “avrdb_firmware” software (link above) is advertised as being common to both - but I don’t know about “the latest version (1.6.2).”

@Robert.Wall
The version that I used came from the drop down box in admin/update/update firmware only


where the full name was

emonTx4 CM single phase, 6 channel firmware with temperature sensing support, Pulse on RJ45 digital. Can be used without an emonVs voltage sensor (current only), lowpowerlabs, v1.6.2

I am using the temperature measurement.

Hope this helps.

@Robert.Wall
Also, the firmware is listed at number 5 on the table in Docs/emonTx4/Firmware