I have on the workbench, a prototype combined ‘Set point’, occupancy, temperature and humidity sensor, touch switch and buzzer.
All designed to fit into a standard 100mm face surface or recessed wall box. ESP32 based so it will talk to OpenHab via Mqtt.
I am going to use it as the basis for my multi zoned heating control system.
Set point is via a simple hardware faceplate knob.
Occupancy via an PIR sensor
Temperature / humidity via a MEMS sensor
A touch switch is available to do pretty much anything I want ( lights etc )
An small internal buzzer can be used as an alarm/call signal.
The device can be battery powered or supplied via in wall wiring ( if replacing a ‘standard’ thermostat the wall wiring is re purposed to carry low voltage AC to the unit )
An onboard ESP32 provides the intelligence and communications.
So, my questions.
Anything else that needs adding?
Do I go onto crowdfunder to get enough together to have a fascia made for this device and offer them to the market? ( About $15000 for moulds and a small production run )
Considering a nest thermostat costs almost $200 would a ‘retail’ price for these around the $100 be reasonable given that with a bit of software and a sonoff switch you’d have the same thing!
I have several extra bedrooms that are not used normally. Occupancy is handy to disable or enable a heating zone. A PIR is a low cost solution to occupancy but can also be used as a alarm sensor.
Batteries … yes putting it to sleep is a requirement to extend the life on batteries. I am sick of replacing batteries ( and disposing of old ones ) so using wired is my solution.
Wireless really is not environmentally friendly is it.
I understand that, but cannot imagine how this is going to work. Somebody enters a room to, for example, take care of plants and heating is turned on for this room because of that. Does not make sense.
But if you put esp to sleep it won’t be able to monitor occupancy during that time. Unless it will be woke up in case of presence.
Occupancy does not need to be a single occurrence thing. As you said watering the plants shouldn’t trigger it but a combination of factors leads to a better solution.
Usually we go in to spare rooms and turn up dumb thermostats if someone is coming to visit. so this is just an added sensor.
Besides that, if you rely on an occupancy sensor to start the heating cycle using underfloor heating, someone is going to be cold for about an hour and a half anyway!
Far better to use the PIR for ‘non occupancy’ instead!
I probably wouldn’t pay more than $40-$60 for something like this. But I’m not a good data point as I have only a single heating zone for the whole house and have no interest in something like this.
When you look at other ESP based commercial products (e.g. Sonoff) the prices are considerably lower.
At $100 this device would have to look really nice.
It’s a bedroom. So what about sleeping? The point druciak is trying to make is that room occupancy is actually one of those hard problems and PIRs alone are almost always inadequate. It could potentially work if the on time is in 10 hour increments (i.e. sense motion and turn on the heat for 10 hours) or add some logic where motion detected around night time will keep the heat on all night but otherwise a PIR is not sufficient to determine occupancy.
