Table 4.
Bill of material.
| Designator | Component | Number | Cost per unit currency (US$) | Total cost (US$) | Source of materials | Material type |
|---|---|---|---|---|---|---|
| MCU | TTGO T8 V1.7 (ESP32) | 1 | 7.70 | 7.70 | Aliexpress | Electronics |
| ACC | EVAL-ADXL355 | 1 | 35 | 35 | DigiKey | Electronics |
| LED | OSTAMA 5B31A | 1 | 0.99 | 0.99 | Starlec OY | Electronics |
| Battery | 16340 (700mAh) | 1–2 | 6.78 | 6.78–13.56 | Starlec OY | Electronics |
| Battery holder | 16340 battery holder | 1–2 | 0.65 | 0.65–1.3 | Aliexpress | Electronics |
| SD-card | SD-card | 1 | 14.34 | 14.34 | Dustin | Electronics |
| Resistor | Resistor (approximately 100 ohm) | 3 | – | – | – | Electronics |
| PCB | Printed circuit board | 1 | – | – | – | Electronics |
| 2 × 3 male pin header | 2 × 3 male pin header | 2 | – | – | – | Electronics |
| 1x15 male pin header | 1 × 15 male pin header | 2 | – | – | – | Electronics |
| 2 × 3 female pin header | 2 × 3 female pin header | 2 | – | – | – | Electronics |
| Magnets | Pot magnet with threaded stem Ø 13 mm | 4 | 2.38 | 11.85 (min order 5 pcs) | Super magnete | Magnet |
| M3 nut | M3 nut | 8 | – | – | – | Fastener |
| Long M3 nut | M3 nut (14 mm) | 4 | – | – | – | Fastener |
| M3x16 bolt | M3 bolt (16 mm) | 8 | – | – | – | Fastener |
| M3x25 bolt | M3 bolt (25 mm) | 4 | – | – | – | Fastener |
| Top casing | Top casing | 1 | – | – | – | 3D-printed part |
| Bottom casing | Bottom casing | 1 | – | – | – | 3D-printed part |