Known Issues

Sometimes issues crop up, and we list them here with their solutions

Hover over graph on Wattmon in Firefox 52+

FireFox recently changed automatic detection of touchscreens when they released v52.0. This affects the hover values because FireFox won't show the hover values if it thinks a touchscreen is being used. To make a long story short, changing this configuration value fixes the problems on systems where FireFox thinks a touchscreen is enabled:

  • about:config
  • Search “dom.w3c_touch_events.enabled”
  • Modify value 2 → 0

Graph page does not show updated values

Sometimes browser caches cause graph pages in Wattmon to show older data. If you are on a graph page (battery status, energy in Watts) and you are seeing old data, press Ctrl + Shift + R to force reload the page.

In some situations, the Onewire temperature sensor does not give values when over 70 degrees celsius. To solve this, edit /config/onewire.ini and add the line: presence_pulse_delay=50 Under the [general] section. Save and reboot, and it should work. The default presence pulse delay is 35 uS.

Blank Functions

Resolved in firmware >= 1.1098 on WattmonPRO and >= 2.1098 on WattmonMEGA

Blank functions cause errors in the Wattmon parser, with the message Invalid } in file ….


function myFunctionThatFails() {


function myFunctionThatWorks() {