Reading a SI7021 sensor via I2C on pi.

Use node 8.x. Never got it working with later node due to issues with "si7021-sensor" package. Tested on a Raspberry PI 3B using raspbian buster.

Configure the raspberry

Enable I2C in raspi-config tool.

Install node: Details: https://github.com/nodesource/distributions

curl -sL https://deb.nodesource.com/setup_8.x | sudo -E bash -
sudo apt install -y nodejs npm

How to run it:

Connect sensor to raspberry pi as follows: SDA on sensor to physical pin 3 on PI (SDA) SCL on sensor to physical pin 5 on PI (SCL) VCC on sensor to physical pin 1 on PI (3v3 power) GND on sensor to physical pin 6 on PI (Ground)

Create .env file with settings according to .env.sample.

Install the prerequisites:

# Run once
npm install

Start the solution:

node app.js

This is one way to launch it every boot using rc.local:

sudo nano /etc/rc.local
# Add this before the exit 0 statement.
# and replace [app-folder] with the folder you are using
su pi -c 'node /home/pi/[app-folder]/app.js   < /dev/null &'