All prototyping parts purchased. Costs normalised to EUR (LCSC USD converted at ~0.92 EUR/USD).
| Component | Qty | Source | Cost |
|---|---|---|---|
| A1304 Hall sensors (SOT-23) | 40 | LCSC | €23.78 |
| CD74HC4051M96 MUX (SOIC-16) | 13 | LCSC | €3.51 |
| 100nF caps (0805) | 100 | LCSC | €0.48 |
| 100nF caps (through-hole) | 100 | AliExpress | €1.08 |
| Owlab Ti HE 40g switches | 50 | AliExpress | €22.99 |
| SuperMini NRF52840 | 3 | AliExpress | €6.78 |
| Kailh hotswap sockets | 40 | AliExpress | €3.39 |
| SOT-23 to DIP adapters | 50 | AliExpress | €2.37 |
| SOIC-16 to DIP-16 adapters | 20 | AliExpress | €1.85 |
| Pin headers 2.54mm (20 pairs) | 1 | AliExpress | €1.80 |
| FNIRSI HS-01 soldering iron (6 tips) | 1 | AliExpress | €38.19 |
| ANENG SZ302 multimeter | 1 | AliExpress | €12.19 |
| Kester 951 flux pen (x2) | 1 | AliExpress | €4.29 |
| 63/37 solder 0.6mm 50g | 1 | AliExpress | €1.17 |
| Solder wick 2.0mm | 1 | AliExpress | €1.19 |
| Breadboard 830-point + jumper wires | 1 | AliExpress | €3.62 |
| Brass wool tip cleaner | 1 | AliExpress | €1.95 |
| Headband magnifier | 1 | AliExpress | €10.99 |
| SMD practice kit | 1 | AliExpress | €2.12 |
| Total | ~€144 |
All purchased components are SMD. For breadboard prototyping:
- A1304 (SOT-23) -> solder onto SOT-23 to DIP adapters + pin headers. Use 6-10 for proto, keep rest for PCB.
- CD74HC4051M96 (SOIC-16) -> solder onto SOIC-16 to DIP-16 adapters. Use 2-3 for proto, keep 6 for PCB.
- Start with SMD practice kit before real components.
Order after prototyping passes.
| Component | ~Cost |
|---|---|
| XIAO nRF52840 dongle | €10 |
| PCBs (JLCPCB, 5 sets) | €25 |
| 703040 LiPo 750mAh x2 (JST PH-2.0) | €6 |
| Passive components, connectors | €13 |
| Keycaps (DSA 1U x36) | €18 |
| 3D printed case x2 | €10 |
| J-Link EDU Mini | €20 |
| Total | ~€102 |
Sensors, switches, hotswap sockets, MUX, caps already purchased.