Dashboard Gauge unit conversion


Using the gauge as a temperature display, the input to it is in F.

I have used the angular expression {{ (payload.currently.temperature - 32) * 5/9 | number:0 }} to convert to C (in the Value Format field).

The numeric display on the gauge is correct, however the icon representation is still showing the value as it would be for F. I am assuming I have done something wrong in the expression above?



Change value in unit field

or append the unit in value field



The Unit Field is as per your first option already. I'll try the second way.


So, it appears the angular expression doesn't like standard brackets, would that be correct?


Problem solved. Always closely examine your input type, just in case it isn't what it appears to be.

Thanks hotNipi


Ok, spoke too soon. Don't believe it is related to my input.

Digging deeper it seems I cannot enclose the payload part of the expression in parenthesis without it throwing a type error.

For example, this {{payload.currently.humidity*(100-5)}} works. But {{(payload.currently.humidity)*(100-5)}} throws an error. Any idea where I'm going wrong?



You probably aren't. Probably a limitation of the expression parser trying to cope with both angular and node-red properties.


Ok, thanks. Good to know I'm not going crazy in this particular instance.


For this particular case (temp conversions), I often just use a range node to convert the value before passing it to the UI widget. E.g. to go from F to C, set the input range from 32-212 and the output as 0-100...


Thanks @shrickus for the tip.