Project Started
Text
USB-C receptacle ├─ CC1/CC2 → 5.1 kΩ Rd → GND ├─ D+/D− → USBLC6-2SC6 ESD → CP2102N USB-UART └─ VBUS → 1.1 A PPTC → BQ24074 IN ├─ BAT ↔ JST-PH 2-pin protected 1S 5000 mAh pack └─ OUT/SYS → TPS63020 synchronous buck-boost → 3V3 CP2102N TX/RX ─┐ ├─ TMUX1574 dual UART selection → XBee DIN/DOUT HC-05 TX/RX ────┘ SEL jumper: GND=USB (100 kΩ default pull-down), 3V3=Bluetooth
Table
| 3.3 V load | Typical | Peak/design |
|---|---|---|
| Digi XBee XR PRO | 28 mA RX | 110 mA TX @ 19 dBm |
| HC-05 | ~30 mA unpaired | 40 mA pairing |
| CP2102N | 9.5–13.7 mA active | 14 mA design |
| LEDs, TMUX1574, passives | ~6 mA | 10 mA |
| Total | ~78 mA | 174 mA |
| Required with 25% margin | — | 218 mA minimum |
Functional blocks
Power budget
Charger settings and safety assumptions