电子戒指FPC设计要求
Thought
Work done
- Started the ring FPC redesign: removed the charging socket/header-class parts and bulky feedback items from the schematic/BOM, including the JST battery socket, SWD header, buzzer, vibration motor, extra switches, and larger LEDs.
- Added smaller ring-FPC-oriented parts: U4 NRF52832-CIAA-R7 WLCSP BLE MCU, SW4 EVQPUJ02K single microswitch, D4 LNJ347W83RA 0402 LED, direct low-profile battery pads P3/P4, and SWD test pads P5/P6/P7.
- Reclassified existing P1/P2 as magnetic charging contacts and kept them wired as CHG_5V and GND.
- Updated passives to 0402 metadata, rewired the new MCU power/reset/SWD/button/LED/charger-status nets, added R9 as the MCP73831 STAT pull-up, and set the board outline request to 72.26 mm × 5.5 mm with 0.15 mm keepout.
- ✅ Charging sockets removed from the active BOM/schematic; magnetic charging contacts are present as P1/P2.
- ✅ Component count and footprint area were substantially reduced; BOM is now focused on compact MCU/charger/LDO/passives/button/LED/contact pads.
- ⚠️ Button centering was not completed in PCB placement; SW4 is wired but still needs physical placement at the FPC centerline.
- ⚠️ Dual-sided anti-interference placement was not completed; the PCB needs final top/bottom distribution and rolled-ring clearance verification.
- ⚠️ ERC/DRC validation was not completed; routing and review remain to be run after placement.
Credits ran out before I could finish placement, routing, and validation. The next pass should place all components on the 72.26 mm × 5.5 mm FPC with SW4 centered on the width, distribute small passives on both sides to avoid rolled-ring interference, route the nets, then review ERC/DRC and remaining mechanical constraints.
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Ring Controller PCBA Requirements
Source
CNIPA_utility_model_ring_controller_application.pdf, extracted for PCBA implementation.
Functional modules
- Ring-shaped wearable control terminal paired with a walkie-talkie and/or AI-capable terminal.
- Internal installation cavity contains: control assembly, communication component, power supply component, and feedback component.
- Control assembly electrically connects to first, second, and third operation parts, communication component, and feedback component.
Controls
- First operation part: walkie-talkie/PTT control such as start talk and end talk.
- Second operation part: AI interaction control such as AI wake, start/end conversation, quick question, smart function invocation.
- Third operation part: mode/auxiliary functions such as mode switching, channel switching, volume adjustment, menu scroll, context switching, confirmation.
- Controls should be distinguishable by tactile features for blind operation; PCBA implements three switch inputs.
Communication
- Preferred wireless implementation: Bluetooth Low Energy.
- Connects wirelessly to walkie-talkie and/or external intelligent terminal such as phone, smart glasses, dedicated host, or AI terminal.
Power
- Rechargeable micro battery preferred.
- Charging interface may be charging contacts or magnetic charging portion.
- PCBA implementation assumption: 5 V magnetic/charging contacts, LiPo charger, single-cell LiPo, 3.3 V regulated electronics rail.
Feedback
- Feedback component may include micro vibration motor, buzzer, status indicator light, or combination.
- Feedback events: control sent successfully, mode switch complete, connection status change, abnormal operation.
Mechanical/layout assumptions
- Compact wearable ring electronics, no exact dimensions in extracted text.
- Control component arranged near center of installation cavity.
- BLE antenna must be edge-exposed/keepout; controls and charging contacts placed at board edge.
- Initial PCB implementation uses a 70 mm × 22 mm rounded-rectangle 2-layer prototype board; final ring flex/rigid-flex outline should be refined with mechanical CAD.
Electrical completion assumptions
- Charging input: magnetic pogo/contact input provides regulated 5 V to MCP73831 VDD; no USB data path is implemented on this first PCBA.
- Battery: single-cell 3.7 V LiPo/Li-ion micro battery with built-in PCM/protection; MCP73831 is configured for about 100 mA charge using 10 kΩ PROG resistor.
- Power path: system load remains connected to the battery while charging; no ideal power-path/load-sharing IC is included in this first pass.
- System rail: AP2112K generates 3.3 V for the BLE module, switches, buzzer, status LED, and MOSFET gate drive.
- Feedback loads: vibration motor is powered from VBAT through low-side MOSFET drive; buzzer is powered from 3V3 through low-side MOSFET drive.
- Debug/programming: compact 1.27 mm SWD header provides SWDIO, SWDCLK, VREF/3V3, GND, and RESET.
Current implementation notes
- U1: MDBT50Q-512K BLE module.
- U2: MCP73831 LiPo charger from 5 V pogo contacts.
- U3: AP2112K-3.3 LDO from VBAT to 3V3.
- SW1/SW2/SW3: active-low GPIO inputs for PTT, AI wake, and mode/aux.
- Q1/M1/D2: VBAT vibration motor low-side driver with flyback diode.
- Q2/BZ1: 3V3 buzzer low-side driver.
- D1/R7: charger status LED from MCP73831 STAT.
- D3/R2: MCU status LED.
- J2/R8/C7: SWD debug plus reset pull-up/filter.
- J1 remains JST-PH placeholder because JST-SH 1.0 mm was not available in the library search.
Source
Functional modules
Controls
Communication
Power
Feedback
Mechanical/layout assumptions
Electrical completion assumptions
Current implementation notes
