This is an rpi thermostat code.
Ideally, this will be simple and stupid.
I've implemented a really dumb Flask web controlling interface. This should be prettified and made mobile friendly.
There are a lot of SD card corruption issues when using this long-term. I should put the OS and the thermostat code on a read-only partition.
Installation
Circuit
I used a Pi Zero W for this, but really any Pi with an internet connection should work.
First, you'll need to connect your Pi to your MCP9808 and relays.
Links to purchased ones.
My circuit is:
The Pi can't sink enough current to turn on the relays, so we use the Pi to turn on transistors and switch the relays from USB power. Note the pull-up resistors.
Note: many AC units don't automatically turn on the fan. Mine didn't, so I shorted yellow to green.
Software
You should install the latest raspbian-lite and set up your Pi to connect to your network on boot.
Then you can install the software:
sudo apt update
sudo apt upgrade
sudo apt install git virtualenv tmux python3-dev ntp
Let those install, then run raspi-config and do the following:
- set your time zone
- enable the I2C interface
Reboot, then you should be able to install pitherm:
git clone https://github.com/rjrosati/pitherm.git
cd pitherm
virtualenv --python=python3 env
source env/bin/activate
pip install -r requirements.txt
Edit your crontab to start the scripts
crontab -e
Mine looks like
@reboot /bin/bash /home/pi/pitherm/start.sh
0 5 * * * /bin/bash /home/pi/pitherm/move_data.sh
Start cron on boot:
sudo systemctl enable cron.service
Scheduling
schedule.txt format:
0-4 20, 4-16 80F, 16-24 20
00-24 24
00-24 24
00-24 24
00-24 24
00-24 24
00-24 24
on monday:
From midnight to 4 am, goal 20 degC
from 4am to 4 pm, goal 80 degF
from 4pm to midnight, goal 20 degC
every other day of week: 24 degC goal constant