# Exercise 14: Power (Charging + Visual)

This exercise is intentionally narrow in scope:
- Detect if a battery is present.
- Detect if USB/VBUS power is present.
- Determine if charging is needed.
- Keep charging enabled through AXP2101 PMU settings.
- Flash the PMU charge LED while charging.
- If fully charged, leave LED off (do nothing).

OLED behavior:
- For the first 2 minutes after boot, OLED shows:
  - `Exercise 14 Power`
  - node name (`NODE_LABEL`)
  - time (RTC/system time if available, else uptime)
  - charging state and battery stats
- After 2 minutes, it switches to a steady `Power Monitor` header while continuing live stats.

## Meshtastic references used
- `src/Power.cpp`
  - charging detection path (`isCharging()`, `isVbusIn()`, battery checks)
- `src/modules/StatusLEDModule.cpp`
  - PMU charging LED control via `PMU->setChargingLedMode(...)`

## Build and upload
```bash
cd /usr/local/src/microreticulum/microReticulumTbeam/exercises/14_Power
pio run -e ed -t upload
pio device monitor -b 115200
```