Sensorlog

Sensorlog is a simple script to read DHT-22 temperature and humidity sensor on your Raspberry Pi and output the results to the terminal/OLED screen/CSV file.

Prerequisites

You need at least RPi and DHT-22 or compatible sensor. (This setup was tested with RPi0w and RPi 3, but should work with any other version).

You need RaspiOS (or Raspbian) with Python 3.5 or newer (which is usually installed by default).

For OLED output you need an OLED screen compatible with Luma.OLED library (any of SSD1306 / SSD1309 / SSD1322 / SSD1325 / SSD1327 / SSD1331 / SSD1351 / SSD1362 / SH1106). By default it uses SSD1306 128x64 screen. If you have screen with different size you might need to adjust "OLED output" section to match your setup. For displaying text on the screen the script is using Ubuntu-Mono-Regular font. You are welcome to change it to whatever you have/need.

For terminal output you need terminal (duh!).

For specific installation instructions please refer to: DHT-22 library: (https://github.com/adafruit/Adafruit_Python_DHT) Luma.OLED library: (https://luma-oled.readthedocs.io/en/latest/install.html)

Installation

Download sensorlog.py file to your RPi home folder (or any other folder when you would like to run this script). The script is ready to be run without preceding it with python3 but in order to do that you have to add execute rights to the file.

chmod +x ./sensorlog.py

but if you'd rather not, that's also fine.

If you use OLED screen and do not have the Ubuntu font family installed, you have to download it and unzip it in the folder of your choice. If you choose non-standard folder you have to adjust script with the path to your font file.

Default fonts installation:

In your home directory (assuming that you are using default pi user) create .fonts directory

mkdir ~/.fonts

navigate to the .fonts directory and download Ubuntu font family there

wget https://assets.ubuntu.com/v1/0cef8205-ubuntu-font-family-0.83.zip

unzip only the font we need

unzip -j ./0cef8205-ubuntu-font-family-0.83.zip ubuntu-font-family-0.83/Ubuntu-R.ttf

you can remove now the zip file with the rest of the fonts if you don't need it.

Usage

If you added execute rights to the script you can run it by simply invoking its name

sensorlog.py

If you prefer to run it with python interpreter and no execute rights, then start it via

python3 sensorlog.py

This should run the script in a simple mode and output the DHT sensor readings to the terminal.

for the full list of options please run

sensorlog.py -h

The script will run until you hit the ctrl-c or the RPi gives up a ghost.

Todo

conversion to F degrees
split script to only load relevant libraries when requested by cli options
make it work with default ugly fonts
add support for E-Ink screens
add parameter for OLED brightness
add rotating OLED through parameters
add section on running the file in the background for long running sessions.
add reading DHT-11 sensor
upgrade to the Circuit Python library

Done

add check for prerequisites and output nice info messages

License

MIT

jakubgg / DHT_Sensor_Log