Bills of Materials
Two BOMs are provided, one for each sensor variant.
| File |
Variant |
bom_co2_only.csv |
CO₂-only sensor |
bom_co2_o2.csv |
Combined CO₂ + O₂ sensor |
Notes
- Prices are approximate UK retail as of 2026 and will vary by supplier and region.
- The O₂ sensor (SEN0322) has a consumable electrochemical cell with a lifetime of approximately 2 years. Budget for periodic replacement.
- All other components (K30, ESP32, level shifter) have indefinite lifetimes under normal use.
Suggested UK Suppliers
| Supplier |
Good for |
| The Pi Hut |
ESP32 boards, level shifters, general electronics |
| RS Components |
MOSFETs, diodes, passive components |
| Farnell |
MOSFETs, diodes, passive components |
| Mouser |
DFRobot SEN0322, sensor modules |
| DigiKey |
SenseAir K30 |
| Waveshare |
ESP32-S3 dev kit |
| AliExpress |
Budget duplicates of most components (longer lead times) |