1st of all i have replaced a thermostat in my livingroom with a tempereature monitoring and internet enabled one built by myself in my livingroom:
Until now i had a thermostat in my livingroom which was a bimetal with a turning knob scaled from 1 to 5 which ment cold or hot. Just the inside part of this thermostat costs at the hardwaresore somewhere around 50 €. To adapt that to the design of the lightswitches and poweroutlets you have to pay another 10-20 € depending on the design. So i decided to go for a replacement.
First i thought about a arduino pro mini with a 0.96 inch spi Oled display, a rotary switch and a ESP8266 Wifi-adapter. That all together costs less than a thermostat from the hardwarestore. Problem was that all that is, although the parts are very small, to large to fit in the hole of the existing thermostat. I also did not find a proper switching power supply. And the most difficult thing of the whole project was that i had to design all the Programming. Sure there is the incredible huge and mighty u8glib, and there are many libraries for the rotary encoder, but i decided to take the thing to another level and came to another solution which fits quite well.
This is my partslist:
- Raspberry Pi Model A+ (24€ because it is small and has less power consumption)
- Pi-TFT form Adafruit. 2.8 inch resistive touch (35 € affordable and in stock)
- edimax nano-Wifi dongle (12 €)
- USB Powersupply (had one laying around but costs 7 €)
- housing (6 €)
- micro SD Card (6€ )
- DS18S20 temperaturesensor (3€)
- Sharp solid state relay (had it laying around.price ? because it is very old and not sold any more)
Here are some pictures:
|new thermostat (sorry german)|
One little thing to mention is that if you want to build the same thing: Do not try to put the RRD-Database on the sd-card. That will destroy the card by time. I am writing the temperature every 5 minutes and therefore i have placed the rrd-database in a ramdisk. To save that i have a cronjob running, that is saving this file every hour to my nfs-server. On boot i copy that file again in the ramdisk by a rc-script. The same procedure comes handy with the prefered temperature, which is written to a file (by the webserver and the wxpythonscript)
So that was the main project i was working on. Right now i am in a project to pimp my hacked IKEA Lamp that i mentioned earlier. Now i try to make a spherical light source that i can project coloured clouds on the Lamp. This could be used to build an palantir. Right now i have 20 WS2812B and a arduino pro mini in mind.
Ok. Thats all for now. If you like i would appreciate if you post comments or like/share. I try to keep this blog alive.