officeAir - A temperature and Humidity Meter and Google Sheet Logger with Raspberry Pi and I2C sensors

This project lets you log temperature and humidity data via Raspberry Pi and a sensor easily and automated way into you google sheet, collecting the raw data and automatically drawing a nice chart as data coming in. (The name and use case comes from life: initially we set this up to monitor DecentLabs office climate in a hot summer period, when air conditioning had some weakness.)

Code by: Róbert Szalóki, Hardware configuration and manual by: Zoltan Dóczi (RFsparkling), Licensed by DecentLabs

First lets see the Google sheet and its script side to prepare that before Raspberry pi configurations.

You can take this example Google sheet (make a copy to yourself and format for your needs):

example google sheet

Here is a chart for temperature and humidity for several days:

And this is how the raw data looks like:

Let's see how to configure RPi and google sheet scripts and web app deploy to enable this "data flow gateway".

1. go to the "script" menu to open the google sheet corresponding and pre-programmed small script:

or you can download the script code file too from the repo here

2. select publish->deploy as web app from the menu there:

3. copy that link (the most important thinkg) which needs to be paste in the future steps into the Rapsberry Pi code (see below in step 8). This key makes a "link" between the RPi and the Google web app server, thus the data will be uploded into the right place: your google sheet.

After the google sheet configuration now see what configuration we need to do under the hood of Raspberry Pi:

4. enable I2C interface at Raspberry Pi

   sudo raspi-config

4b. connect the sensor to the RaspberryPi's corresponding pins as shown below:

5. install i2c-tools to be able to reach the sensor and check its status

   sudo apt install i2c-tools

6. veryfication of I2C sensor:

   sudo i2cdump -y 1 64

#should look like somthing like this:

7. creating log script to execute I2C sensor call and google web app data upload:

sudo nano log

8. copy paste this into log, take care to modify the web app key what you copied at setp 3 above

#/bins/sh
DATA=`sht21.py`
curl -L "https://script.google.com/macros/s/**copy your Google script deployed web app key here**/exec?$DATA"

9. set rights

sudo chmod +x log

10. copy the python script into the proper folder:

cd /usr/local/bin/log
sudo wget https://github.com/DecentLabs/officeAir/blob/master/sht21.py
sudo chmod +x sht21.py

11. modifying crontab to execute the script every minuite

sudo nano /etc/crontab

11b. and copy paste to the last line this:

*  *    * * *   root  /usr/local/bin/log #log air quality

Finally reboot the RPi, once it comes back it should report temperature and humidity values every minute to the google sheet

sudo reboot