As I can’t find any home automation commercial product nor DIY project that suits my needs and my requirements, I’m going to design my own assets…
“MUTA” : my home automation project
As of today, I plan to use :
– A server application hosted on a Beagleboard (because of the low consumption, but it could be of course done on any other enough powerfull and “always-on” device as PC), based on some Raphaël JS /AJAX /Cherrypy / SQLAlchemy / Python mix (so platform & OS independent). A basic USB device (with multi-platform drivers) would enable access from the host platform to the dedicated wireless network.
– Wireless devices, dedicated to interfacing and managing sensors or controllers, they should be easily set up and be cheap.
The cost of the different devices (server wireless interfacing or sensors/controllers) should be kept as low as possible. A target cost of 10 to 15 euro would be great.
The UI and the features list should respect the KISS design principle.
I’ll begin by doing a prototype of the core application with 2 basic devices (temperature sensor and heating control) for temperature & heating regulation.
Keep the cost looooow
For this purpose, I won’t use any boost module, they are too expensive. Using two AA rechargeable batteries, I’ll have to deal with a 2V-2.4V supply voltage range, nothing more!
For the same reason, I won’t choose any Zigbee-like protocol for the wireless network. As an example, the cheapest Zigbee module costs $22 at Sparkfun!
I’ll try to use the RFM23 434MHz transceiver from HopeRF instead… The features list is great and it is priced under $5! (and it runs perfectly at 2V). Using a very basic and simple communication protocol, it should be a very good base.
The same approach led me to Microchip microcontrollers for the USB connectivity. The PIC18F14k50, for example, integrates an USB interface for a retail price of ~2 euro. That’s way cheaper that the FTDI or Silicon labs USB modules…
And the latest “XLP” devices from microchip seems to be as battery-friendly as the TI MSP430, so that would be a good alternative too…
(Muta image courtesy of Studio Ghibli, from “the cat returns”/”Neko no Ongaeshi”)