Bill of material
Jump to navigation
Jump to search
Overview of Parts (V1)
Mandatory Components
- bcMeter Pi Hat — Order prepopulated (~95 EUR) or build your own from PCB + components (~5 EUR per PCB for 10+ on JLCPCB or similar)
- Raspberry Pi 3A or Zero 2 W (~35 EUR)
- MicroSD Card (~10 EUR)
- Power Supply 5.25V/2A (~15 EUR)
- Air Pump (~10–200 EUR depending on type)
Populated PCBs are available — contact jd@bcmeter.org.
3D Printed Case
STL files for 3D Printing (SLA or FDM): GitHub repository — printing material ~10 EUR.
Use black filament/resin. FDM is prone to leakage if not properly configured. If possible, mix resin with flex resin.
Filter Paper
AE33 filter paper is standard for bcMeter. Any filter paper with a known scattering factor can be used. See Supported Filter Papers for correction factors.
Send a sample of your filter paper to jd@bcmeter.org for calibration.
Additional Material (~75 EUR)
| Description | Quantity | Approx. Price |
|---|---|---|
| 22 AWG Wire | 1 | $10 |
| Hot Glue | 1 | $7 |
| Rubber Band (SHORE A) for sealing | 1 | $13 |
| Silicone Hose (5mm ID) | 1 | $5 |
| M3 Screws | 1 set | $7 |
| M3 Threaded Inserts | 1 set | $7 |
| MicroSD Card 16GB | 1 | $8 |
Key PCB Components
| Component | Description | Approx. Price |
|---|---|---|
| U1 MCP3428 | 4-Channel ADC | €6 |
| D1/D2 IRL81A | IR LEDs (880nm) | €2 |
| J1 Omron D6F | Airflow Sensor | €50 |
| U2 LM1117 | Voltage Regulator | €1 |
| U3 SHT4x | Humidity/Temp Sensor | €4 |
| Pump D15S PWM | Membrane Pump | €95 |
| Capacitors, resistors, connectors | Various | ~€20 |
Full BOM with exact product numbers available at GitHub.
PCB / Gerber Files
Gerber files for PCB fabrication: GitHub
Two PCB variants exist:
- SMD PCB — For 5V and smaller pumps. More compact, recommended.
- THT PCB — For 12V and larger pumps. Easier to assemble but less accurate.
Current Platform (ESP32)
The current bcMeter uses an ESP32-S3 with a different hardware design:
- ADS1220 24-bit ADC (replaces MCP3428)
- ESP32-S3 DevKit-C-1 (replaces Raspberry Pi)
- LittleFS internal storage (replaces microSD)
- Optional: SIM7080G LTE-M modem, AT6668 GPS, SPS30 PM sensor
For current device information, see Introduction.