(ab)using 'spare' inputs to measure 'other things'


#1

Has anyone tried it?
Am I right to think that simple voltage divider with thermistor etc. should just work
(calculator could take care of required degC conversions)

I know its not ‘meant’ to be used like this… but inputs should never be wasted :slight_smile:

M.


#2

In the early days, I had a notion to support other input types, and the code is modular enough to do so. But it would require some work for the cases I had in mind.

For temperature, I had thought that standard 10K sensors could be supported with a voltage divider as you say, although that would require some modifications to the input jack to supply 3.3V and ground. Not a trivial change.

More useful might be to support 4-20 ma input. This is pretty much the standard for a host of industrial sensors, from liquid level, to flow rate, to CO2 level, etc… That would not require any modification to the hardware, and reading the sensor is trivial because it is just a single ADC read of the DC input as opposed to integrating AC as in power readings.

But this is all for you tinkerers. I have no plans to complicate the current product. Should I get the time to redesign, there are a lot of options to explore.


#3

Or, just get a wemos D1 and put Tasmota on it and have support for just about any sensor you might want and control relays too.

As the saying goes use a hammer for nails and a screwdriver for screws. Just because you have a hammer doesn’t mean it is a good idea to use with your screws :grinning: