My brother has a project that I would like to do with Arduino, but he is hundreds of miles away and his idea of solder is a TIG welder.
Backstory:
He has a 3-phase compressor that is powered from a three-phase inverter. (His building only has 220V two-phase and he needs 380V three phase). Currently when the compressor pressure valve calls for more air someone has to go into the service area and manually turn on the inverter to power the compressor. His problem is that when the compressor is up to pressure, no one goes back to turn off the inverter.
My solution would be a Wemos D1 Mini on the compressor regulator contacts. When the compressor regulator switch closes, I would send an MQTT message to another Wemos D1 Mini at the inverter which would close a relay contact to start the inverter. After a few seconds the Wemos on the compressor would close a relay to turn on the compressor.
If you use the key-fob and the matching receiver, you are pretty much assured the coded pair will work and other fobs and transmitters will not activate the receiver. As stated, there is no reason not to remove the case-two screws- and just use the fob innerds.
My recent experience is there are three possible actions you can program the receiver to perform with a matching 2 button fob:
turn the internal relay on with button A. Turn the receiver off with button B.
turn the internal relay on with button A and remain on until button A is pressed again.
turn the internal relay on as long as button A is pressed. Relay is off when button A is off.
Your results may vary.
Paul
EDIT:
Are you really looking for something that is neither a "keyfob" nor a "bare board"? What is it looks like?
Now I have the same question as #2 and #3...
They all seem to be keyfob types, but googling did turn up a huge variety of them, and a few looked more like TV or AC remotes.
Do we understand that the (commercial) transmitter is to be used without modification, and your brother will somehow deal with getting the matching receiver wired into the proper circumstance to become functional
as a bridge solution until
you have created the final no doubt impressive and amazing device?
Be careful not to do too good a job with the bridge solution. Good or even adequate solutions tend to remove motivation to work on better or best solutions.
I have several of the 433 mHz pucks around my house, but he wants something he can screw two wires from the pressure switch to the transmitter, two wires to the compressor relay and at the converter, screw two wires in parallel with the switch.
I've seen his soldering- no chance of modifying a puck or keyfob without melting down the whole device. This is what he uses for soldering:
However, I've convinced him to wait until I make a system for him. It occurred to me that the transmitter would need a momentary closure and the pressure switch would either be on or off. Definitely need an Arduino in the solution.
