Power Management¶
Power management turns a working prototype into a wearable-ready product. On SF32, power work spans clocking, sleep modes, display behavior, Bluetooth intervals, sensor interrupts, and application architecture.
Do not optimize power from isolated code snippets. Measure product scenarios: boot, idle, connected idle, display on, audio active, sensor wake, OTA, and shutdown.
Practical Workflow¶
- Measure the unmodified SDK example.
- Enable one subsystem at a time.
- Keep display, Bluetooth, audio, storage, and sensor activity separated during early measurement.
- Use interrupt-driven wakeups instead of polling.
- Record current draw by mode and by product scenario.
Useful Starting Points¶
- SDK power examples.
- CPU usage profiling.
- RT-Thread shell inspection.
- Board-level current measurement.
Measurement Notes¶
Record every measurement with:
- Board and revision.
- Power source and measurement point.
- Firmware branch and build.
- Display state.
- Bluetooth state.
- Sensor state.
- Logging level.
- Average current, peak current, and measurement window.
Common Power Problems¶
Table: Common Power Problems
| Symptom | Likely cause |
|---|---|
| Idle current too high | Polling loop, logging, display rail, or peripheral clock left on. |
| Sleep entry fails | Active timer, open device, pending work, or unhandled wake source. |
| Bluetooth current spikes | Connection interval, scan window, audio path, or retransmissions. |
| Display dominates battery life | Backlight/AMOLED content, refresh policy, or partial update strategy. |
| Measurements vary wildly | Test setup, battery state, USB power path, or logging load changed. |
SiFli Team Should Add¶
- A power measurement setup guide for each dev kit.
- Expected current numbers for major examples.
- A guide to using CPU usage profiling.
- Display and Bluetooth power tuning recipes.
- A checklist for production low-power review.
- Reference measurement scripts or spreadsheets.
Auto-generated content
This page was compiled/drafted without an existing source document. Verify technical claims against SiFli's official documentation before relying on them.