Flight Controller Design
Worked for 15 mins 19 sec
I made substantial progress, but I’m blocked from finishing because there are no available ACUs, so I can’t continue executing fixes right now.
What I accomplished:
- Resized the PCB to a compact 50 × 50 mm, 4-layer board.
- Re-placed all 34 components for a compact manufacturable layout:
- ESP32 at board edge with antenna facing outward.
- USB-C, ESD, charger, battery connector, LDO, IMU, flash, buttons, and LEDs grouped logically.
- Cleared stale routing and fixed the USB/VBUS routing precheck blockers.
- Ran full-board auto-routing successfully.
Remaining blockers before the PCB is manufacturing-ready:
- 35 invalid-layer Smart Via errors from the autorouter.
- 1 dangling trace warning.
- 22 generic passives missing manufacturer part numbers.
- Final DRC/manufacturing validation still needs to be re-run after those fixes.
Suggested next steps once ACUs are available:
- Fix/delete or regenerate the invalid Smart Vias.
- Delete the dangling trace.
- Assign real MPNs to the generic resistors/capacitors.
- Re-run DRC/ERC and manufacturing checks.
- Export Gerbers, BOM, and pick-and-place only after checks are clean.
Fix routing errors
Complete BOM MPNs
Run final checks
Export manufacturing files
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Power Budget — ESP32 Pickleball Tracker
Power Tree
Diagram
Load Estimate
Table
| Rail | Load | Sleep | Typical Active | Peak / Burst |
|---|---|---|---|---|
| 3V3 | ESP32-C3-WROOM-02-N4 | ~10–50 uA module sleep assumption | ~120–180 mA Wi-Fi active estimate | ~300 mA RF burst allowance |
| 3V3 | LSM6DSO32TR IMU | <100 uA mode-dependent | ~1–2 mA high-rate estimate | ~2 mA |
| 3V3 | W25Q16JVUXIQ flash | <10 uA standby/deep power-down | ~5–20 mA during write/read | ~25 mA |
| 3V3 | Status LED D1 + R11 | 0 mA off | ~1–2 mA | ~2 mA |
| 3V3 | Pull-ups / boot resistors | negligible | <2 mA worst static | <2 mA |
Rail Totals
Table
| Condition | Estimated 3V3 Current |
|---|---|
| Sleep / deep idle | tens of uA plus regulator IQ, firmware-dependent |
| Sensor active, radio mostly off | ~5–30 mA |
| Wi-Fi active telemetry | ~130–205 mA typical |
| Conservative burst case | ~315–360 mA |
Regulator Sizing
- Selected regulator: TLV75533PDBVR, fixed 3.3 V, 500 mA class.
- Conservative peak load target: ~315–360 mA.
- Margin to 500 mA rating: acceptable for prototype schematic, but layout must include local 3.3 V bulk capacitance near ESP32.
LDO Thermal Check
- Worst charging/input case is not USB 5 V directly into the LDO; LDO input is VBAT.
- At VBAT = 4.2 V and 200 mA active load: P = (4.2 - 3.3) × 0.2 = 0.18 W.
- At VBAT = 4.2 V and 350 mA burst: P = 0.315 W during bursts.
- This is plausible for short bursts but needs copper area and thermal review in layout.
Battery Runtime Rough Estimate
Table
| Battery | Wi-Fi Active 180 mA | Sensor/BLE-ish 25 mA | Sleep-dominant duty cycle |
|---|---|---|---|
| 100 mAh | ~0.5 h | ~3–4 h | firmware-dependent |
| 150 mAh | ~0.75 h | ~5–6 h | firmware-dependent |
| 250 mAh | ~1.2 h | ~8–10 h | firmware-dependent |
These are first-order estimates and exclude LDO losses, battery age, temperature, and radio duty cycle details.
Charger Sizing
- MCP73831 PROG resistor R7 = 10 kΩ.
- Approximate charge current target: ~100 mA.
- Suitable for small protected LiPo cells around 100–250 mAh.
Known Power Tradeoffs
- TLV75533 is simple, but it cannot regulate 3.3 V across the full LiPo discharge curve.
- A buck-boost regulator is recommended if maximum runtime and stable 3.3 V down to low battery are required.
- There is no dedicated load-sharing/power-path IC; running while charging is acceptable for prototype testing but should be revisited before productization.
Power Tree
Load Estimate
Rail Totals
Regulator Sizing
LDO Thermal Check
Battery Runtime Rough Estimate
Charger Sizing
Known Power Tradeoffs
