Christmas ball

Dancing around the christmas tree, unwrapping presents and having a good time together with the family can lead to a lack of time perception. Over time the level of CO2 will accumulate to a level that can cause headache, which is a horrible way to end christmas night. This christmas ball will show when the level of CO2 is above a given threshold. I decided to have a threshold of 2000 ppm, but according to dhs.wisconsin.gov a level below 1000 is to be prefered.

Step by step

1. Components

The project uses the following components:

1. ESP32-wroom-32E development board
2. SCD30 sensor
3. NeoPixel Jewel LED module
4. Battery
5. Cables

2. Putting everything together

Put everything together as shown in the image. The ESP32 pin connection to the SCD30 sensor is as follows:

• GPIO21 > SDA
• GPIO22 > SCL
• 3.3V > 3V
• GND > GND

NeoPixel Jewel

• GPIO27 > Data input
• GND > GND
• 5V > 5V DC

3. Running the program

I used Jaguar from Toit as it is really fast for developing in a non test-driven prototyping environment. It offers hotreload in a second, with the watch command.

Read more on how to set it up at Toit Jaguar.

Afterwards:

jaguar watch src/main.toit

4. Enjoy christmas without a headache

I found that the level of CO2 is usually too high in my working environment and it sure increases production to let some fresh air in.