One side project I started last night was a Thermostat Device Type & SmartApp. My flat has digital but still very 70’s thermostats for each room’s underfloor heating, When a couple of 10K Ohm resistors arrive I will hopefully accurate floor temperate readings from the two analog wires going to the thermostats and have checked the specs and ordered two crazy arsed 16A relays (the latest version go the thermostat states 16A so best conform).
I also with to use a Nano and have the unregulated 20V PSU integrated using a Myrra PCB Mount Power Supply. As there’ll be a few different things needing power, a temperature sensor of its own, a current sensor to know what its costing over a period of time and I may put an OLED LCD touchscreen in if there’s any room left. It would look super cool with the flush blank faceplates I’ve found.
I’m in the UK so our back boxes are 86mm x 86mm (more depth could be added I suppose (just occurred to me). Anyway a Nano with an XBEE4-NANO and Xbee Module will make things tights in an already tight area. While the apartments are lovely they were not constructed well, There’s very little length of spare cable and the backbone is filled with plaster (the one I’ve looked at so far).
I’m well acquainted with SSDP, I wrote an async implementation in C# yesterday which allows listeners etc. In this instance its to find the Hue Bridges (I only have two as I bought a redundant bridge on eBay at a good price just to test this code, it will be resold shortly, I think I have 20 bulbs out of 50 left, 8 with 2 more to follow are due to be ordered soon and I may add in-decking spots in the next few months if I can find a suitable weatherproof unit that will take a Hue GU10 so hmmmm, perhaps keep it!!!).
So after that mega-ramble (couldn’t sleep last night, was woken by neighbour 2am Sunday morning so a bit oooh). What is everyone’s preferred way of connecting these days?)
I don’t mind the idea of Wifi using something like this:
There seems to be a pretty comprehensive ESP8266 library for Arduino now. Soft-AP mode so like my old Bose Soundlink Air when reset would present itself as a mini-site, listing all available networks and allow you to connect to the one your ST hub lives on that way. I’m pretty sure the WeMo Insight does the same.
It’s stupid cheap too and bah but buggerr!!! No less in length than the XBEE4-NANO shield.
With regards to either XBee or Wi-Fi I don’t mind more devices on the 2.4GHz channel. All the Mac’s and TVs use the 5GHz channel. Regarding Z-Wave its near impossible to source parts from my regular places in the UK.
My new Samsung hub has arrived so that will allow for Bluetooth discovery too?
What do you guys prefer and if Z-Wave where do you get them from? Small is key but cost counts too.
Oh and the whole reason for not just putting in an existing ST friendly thermostat is that as far as I’m aware there aren;t and compatible with DEVI flooring systems. And most are made for US sized back boxes. Plus it’ll be fun.
I also have the chance of building these to sell. There’s at least a 750 apartments in my complex with the same crappy system and just about everyone here will have a Smartphone. So cost comes into it again.
I have just found this which is much smaller:
A lot more expensive though (well not really but when you’re after 6 for yourself and the chance of selling… Not easy to get here either, not without paying more for shipping than the device costs. For example £41.04 + £12.93 postage = £53.97 / $83.79 for a $9.95 item. There are two for sale in the UK for around £10 but they are the version without the pins. I’d prefer the other type and all soldering gets sent out to be done.