Even a small increase of CO2 in the air by volume can be hazardous. While most people will never encounter CO2 levels above 1% indoors, the increased use of pressurized CO2 storage tanks in businesses has increased the likelihood of exposure to high levels of CO2. At 1% CO2, people can start to experience accelerated heart rate. At 4%, CO2 levels can be fatal. Normal CO2 levels in fresh air is approximately 400 ppm (part per million) or 0.04% CO2 in air by volume. The table below shows the effects of increased CO2 levels in an enclosed space as a percent of air by volume.
| ppm | Effect |
|---|---|
| 400 | Normal outdoor air |
| 400 - 1000 | Typical CO2 levels found indoors |
| 1000 - 2000 | Common complaints of drowsiness or poor air quality |
| 2000 - 5000 | Headaches, fatigue, stagnant, stuffiness, poor concentration, loss of focus, increased heart rate, nausea |
- Waveshare 1.28inch Round LCD Display Module (240×240 65K RGB)
- OEM ESP32 Development Board - DEVKIT V1 (ESP-WROOM-32 module) like this or that
- SCD41 CO2 sensor Breakout Board - The SCD41 is miniature CO2 sensor, which builds on the photoacoustic NDIR sensing principle and Sensirion’s patented PASens® and CMOSens® technology to offer high accuracy at an unmatched price and smallest form factor.
Display, you don't need to use pin numbers if useing "normal" SPI:
| LCD | ESP | Code |
|---|---|---|
| VCC | 3V3 | |
| GND | GND | |
| DIN | MOSI | |
| CLK | SCK | |
| SC | D27 | 27 |
| DC | D26 | 26 |
| RST | D25 | 25 |
| BL |
SCD41 uses I2C, so this is the plan:
| SCD41 | ESP | Code |
|---|---|---|
| GND | GND | |
| VCC | 3V3 | |
| SCL | SCL | |
| SDA | SDA |
- Bodmer make a great comment how to draw an arc.
- truetype2gfx converts TTF to GFX
- Please note that
canvasdoesn't wotk with custom fints - Some great online RGB565 Color Picker
