Relay in Reverse - Switching Arduino Based on Input from Netatmo Relay

Hi,

This is a bit of a strange one. I am in a property where I can't interfere with the boiler or have anyone interfere with it for me and would like to fit my Netatmo relay. There is a basic control panel on the front of the boiler I plan on controlling via a couple of solenoids (temp up / down) based on input from the Netatmo thermostat / output from its wireless relay. My worry is at the Arduino side - I assume there is some voltage danger to the Arduino if wired directly to the output of the relay.

Is this correct? What would the best approach to this be?

Thanks for reading.

I assume there is some voltage danger to the Arduino if wired directly to the output of the relay.

There is a danger to the Arduino if supply or input voltages are too high, wrong polarity is applied or too much current is drawn from the pins.

What voltage range does the relay output ?

That would be a yaler?

UKHeliBob: There is a danger to the Arduino if supply or input voltages are too high, wrong polarity is applied or too much current is drawn from the pins.

What voltage range does the relay output ?

All I can find are maximums, no mention of the range:

Maximum switching current: 4 A. Maximum switching voltage: 250 VAC. Maximum switching capacity: 120 VA (4A load @ 30V, 1A load @ 110V/120V or 0,5A load @ 220V/240V).

Please can you explain in more detail what you are trying to do ? What is connected to what and how does the Arduino come into it ?

I have a boiler I cannot modify and want to use it with my Netatmo thermostat so need an interface to physically trigger the boiler on or off from the relay output of the Netatmo. Basically, when the Netatmo's relay switches, the Arduino would read that and press a button or turn a dial.

when the Netatmo's relay switches, the Arduino would read that and press a button or turn a dial.

Press a button or turn a dial where ?

There is a button on the front of the boiler which can be set to on, auto or off (so on off). The existing thermostat on the boiler has a simple rotary encoder to set the temperature. I would probably turn that with something (servo or stepper motor) rather than try with the button.

windswept321: There is a button on the front of the boiler which can be set to on, auto or off (so on off). The existing thermostat on the boiler has a simple rotary encoder to set the temperature. I would probably turn that with something (servo or stepper motor) rather than try with the button.

Do I really understand this? You want to modify the boiler system, without modifying the boiler system? Adding something to the front of the boiler is modifying in my book.

Paul

The existing thermostat is wireless, although not ‘smart’.

So smart wireless thermostat to its relay to arduino to existing ‘dumb’ wireless thermostat to boiler.