Log No. 4

A project log for Raspberry Pi Heating System

A heating system based on the Raspberry pi to control relays and valves.

Colin ConwayColin Conway 05/27/2016 at 11:230 Comments

Finally got the ESP8266 code and wiring sorted. I used a board schematic I made a while back as a breakout for the ESP8266-12E so I could use it to control some neopixels (one pin has a 2n7000 as a level converter). I've modified it a bit to include some additions for this board (most notably the header for a jumper to enable deep sleep mode).

I also created an IO board out of perf board to handle a 5v regulator (your bog standard LM7805) as the HC-SR04 needs 5v to take all the incoming devices, ground and power them and to handle the voltage divider for the battery level reading (it was easier than designing and etching a totally new board). Only issue with this setup is there are a heap of wiring back and forth from the ESP board to the IO board. I'll design one and upload the schematics when I haven't got a heap of deadlines to meet!

This certainly is more reliable than the 433mhz version, probably due library used in python, or maybe the amount of threads (btw I'm testing this on a Raspberry Pi B rev 2 board to ensure its compatible with ll Pis). I was actually tempted to use an ATTINY85 as a 433mhz proxy, with software serial to communicate with the pi and connect the radio devices to that instead, but I thought I was getting way to complicated for that.

Oh and I fixed the weather issue, apparently Yahoo changed their API so the library I was using (which hasn't been updated in some time) couldn't communicate with it. I've also added a python script to change the location of the weather report in the setup script. Completely forgot it was set to my locale in the script!

Next job is to resize the screen contents according to the resolution of the screen attached. I'm thinking I might get a 800x600 5inch screen just to test, but that wont be for another month or so before it arrives.

Oh and I'm thinking maybe of adding to the project to include it in the next round of the Hackaday contest (citizen scientist), maybe add MySQL or MariaDB to the Pi and logging everything from the amount of Oil used compared to the amount of minutes the heating is on. Maybe throw that together with the temperature difference between outside and inside the house and plot the whole thing as an efficiency thing or maybe output the CO2 produced. Not sure - worth a think I think!

Onward and Upward.