Tutorial: Bluetooth CO2 Monitor with SCD30
This tutorial enables you to setup a CO2 monitor sending CO2 measurements via Bluetooth to nearby mobile phones. All steps necessary and a compatible app for Android and iOS are provided here.
The tutorial is structured in three parts:
- Hardware Setup: Learn how to wire the sensor to the development board
- Software Setup: Learn how to setup your computer to program the development board
- Monitor Setup: Learn how to monitor your CO2 levels on your computer and via the "Sensirion MyAmbience CO2 app"
If you have a LILYGO® TTGO T-Display ESP32 then make sure to follow the instructions on the very bottom of this tutorial to enable the UI of your gadget.
To complete this tutorial, you'll need:
Connect the SCD30 sensor as depicted below:
- Connect the 3.3V to the 3.3V pin of the ESP32
- Connect GND to GND on the ESP32
- Connect the SDA pin to GPIO 26
- Connect the SCL pin to GPIO 27
Setup the Arduino IDE for the ESP32 platform
The following instructions originate from here.
1. Install the current version of the Arduino IDE.
2. Start the Arduino IDE and open the Preferences window.
3. Enter the following link above into Additional Board Manager URLs field. You can add multiple URLs, separating them with commas.
4. Open the Boards Manager from Tools > Board -> Board Manager and install the esp32 platform
5. Select your ESP32 board from the Tools > Board menu after the successfull installation.
- E.g. ESP32 Dev Modul
Setup the required libraries
We'll be installing 2 libraries. Click the links below and download the newest .zip release packages
For each of the downloaded .zip files: In the Arduino IDE, select Sketch -> include Library -> Add .zip Library and select the .zip file.
Launch the CO2 Monitor
1. Open the Arduino IDE.
2. Go to: File -> Examples -> Sensirion Gadget BLE Lib -> Example2_SCD30_BLE_Gadget.
3. Make sure the ESP32 is connected to your computer.
4. Press the Upload button on the top left corner of the Arduino IDE.
Value plotting on your computer
To verify that everything is working fine, open the Serial Plotter, while your ESP32 ist still connected to your computer to see the sensor values measured by the SCD30 sensor:
1. Go to: Tools -> Serial Plotter
2. Make sure on the bottom left corner "115200 baud" is selected, as depicted in the image below
Monitor your CO2 levels via Mobile App
Download the Sensirion MyAmbience CO2 app to monitor your CO2 levels, download history values and export and share the data with your friends.
Note that on Android devices the Location services need to be enabled and the corresponding permissions granted to the application. This is required to allow the app to scan for nearby Bluetooth devices. This is a requirement of the Android OS for Bluetooth scanning. The app itself does not use your location.
Additional Steps for LILYGO® TTGO T-Display ESP32
The LILYGO® TTGO T-Display ESP32 is an ESP32 DevKit with a small 1.14 inch display attached. This allows us to visualize the current CO2 concentration and level color in green, yellow or red, depending if the CO2 level is good, bad or very bad.
Follow all the instructions above and additionally do the following:
1. Go to TTGO T-Display's Github Repository
- Download the code as zip and extract its content
2. Copy the Folder "TFT_eSPI" to your Arduino library path
- On Windows, this is by default: C:\Users\Your User Name\Documents\Arduino\libraries
3. In the same library path, open the Sensirion Gadget Ble Arduino Library folder, then Examples, then Example 3 and copy the content as follows into the "TFT_eSPI" Folder
- Copy all files in the folder "fonts" to "TFT_eSPI/Fonts/Custom/"
- Copy the file" User_Custom_Fonts.h" to "TFT_eSPI/User_Setups/"
4. In the Arduino IDE, open Example 3 by clicking on File -> Examples -> Sensirion Gadget BLE Lib -> Example3_SCD30_BLE_TTGO_Gadget
5. Press the Upload button