zyphlar
4.2 KiB
4.2 KiB
Ordering & Assembly Guide
JLCPCB Order Settings
Upload baby-mobile-panel.kicad_pcb gerbers with these options:
| Setting | Value |
|---|---|
| Layers | 2 |
| PCB Thickness | 1.6mm (carrier) / 0.8mm works too |
| Surface Finish | LeadFree HASL (cheapest) or ENIG |
| Castellated Holes | Yes (required for adapters) |
| V-Score | Yes (break between carrier and adapters) |
| Quantity | 5 (minimum) |
| Estimated Cost | ~$8 for 5 panels |
If ordering JLC assembly (SMT), upload carrier_bom_jlc.csv.
Otherwise, hand-solder the carrier components yourself — everything
is 0805 or larger except the TPS61220 (SC-70-5, fine-pitch but doable
with flux and a fine tip).
Carrier Board BOM
| Ref | Part | Package | LCSC | ~Cost | Notes |
|---|---|---|---|---|---|
| U1 | TPS61220DCKR | SC-70-5 | C83951 | $0.80 | Pin 1 dot on silk |
| U2 | IS25LP128F-JBLE | SOIC-8 | C194872 | $1.80 | Pin 1 dot on silk |
| L1 | 4.7µH inductor | 0805 | C408336 | $0.15 | |
| C1 | 10µF ceramic | 0805 | C15850 | $0.05 | Boost input |
| C2 | 10µF ceramic | 0805 | C15850 | $0.05 | Boost output |
| C3 | 100nF ceramic | 0805 | C49678 | $0.01 | Flash decoupling |
| C4 | 100nF ceramic | 0805 | C49678 | $0.01 | (optional XIAO decoupling) |
| C5 | 10nF ceramic | 0805 | C1710 | $0.01 | Audio LPF |
| R1 | 4.7KΩ | 0805 | C17673 | $0.01 | Audio LPF |
| R2 | 10KΩ | 0805 | C17414 | $0.01 | Flash CS pullup |
| J1 | JST SH 10-pin SMD | 1.0mm | C160404 | $0.30 | Right-angle |
| J2,J3 | Female header 1×7 | 2.54mm | C124378 | $0.20 | XIAO socket (×2) |
| — | Seeed XIAO nRF52840 | module | — | $9.90 | From Seeed/Amazon |
| Carrier subtotal | ~$13.30 |
Not on PCB (buy separately)
| Item | Source | ~Cost |
|---|---|---|
| JST SH 10-pin cable (both ends female) | Amazon/AliExpress | $1.50 |
| 30AWG wire (for adapter-to-JST) | Amazon | $5/spool |
| 2×AA battery holder | Reuse from toy | $0 |
Breakaway Adapter BOM
The adapters are passive PCBs — no components except one JST SH connector each. Buy the connector that matches your adapter:
| Adapter | JST SH Pins | LCSC | ~Cost |
|---|---|---|---|
| SOP-8 | 8-pin | C160402 | $0.25 |
| SOP-16 narrow | 10-pin | C160404 | $0.30 |
| SOP-16 wide | 10-pin | C160404 | $0.30 |
You only need one adapter per toy — snap off the right one.
Assembly Order
1. Carrier board (do this first, test before connecting to toy)
- Solder U1 (TPS61220) — align pin 1 dot. Tin one pad, place chip, reflow that pad, then solder remaining 4 pins.
- Solder L1, C1, C2 — boost converter circuit. Apply 2×AA battery voltage to VBAT/GND test points. Measure 3V3 output — should read 3.30V ±0.1V.
- Solder U2 (IS25LP128F) — align pin 1 dot. Same technique as U1.
- Solder C3, R2 — flash decoupling and CS pullup.
- Solder R1, C5 — audio RC filter.
- Solder J1 (JST SH) — align pin 1 mark.
- Solder J2, J3 — XIAO female headers.
- Plug in XIAO — USB-C faces the left edge marked on silk.
- Test — upload pin_discovery.ino, verify serial output.
2. Adapter board
- Snap off the adapter matching your toy's MCU package.
- Solder JST connector to adapter's top surface.
- Desolder original MCU from toy PCB (hot air or iron + flux).
- Place adapter in empty footprint, pin 1 aligned.
- Solder castellated edges — the half-holes sit on the SOP pads. Apply flux, touch with iron, solder wicks into the half-hole.
- Plug JST cable from adapter into carrier J1.
3. Map and wire
- Upload pin_discovery.ino to XIAO.
- Use multimeter + the serial tool to identify each SOP pin's function.
- Create your pin map (see BRAIN_TRANSPLANT.md).
- Update baby_mobile_v2.ino pin definitions.
- Upload final firmware.
- Upload audio via USB mass storage.
Silkscreen Guide
All polarized components have pin 1 dots (●) on the silkscreen:
- U1 (TPS61220): dot near pin 1 (VIN)
- U2 (IS25LP128F): dot near pin 1 (~CS)
- J1 (JST SH): dot near pin 1 (VBAT)
- Each adapter: dot near SOP pin 1
The XIAO outline shows the board rectangle with a USB-C bump on the left edge. Pin labels (D0-D10, 3V3, GND, 5V) are printed next to each header hole.