ISP1907 Part Swap

flux

The via was reduced by applying the project ruleset “U1 escape vias” to the via’s full PCB node ID:
Text
[uid="ab203441-d5da-4e1a-bbff-4206d0ec2e14.throughHole.0-0"]
The four fields that worked were:
Text
Size X:      0.4 mm
Size Y:      0.4 mm
Hole Size X: 0.2 mm
Hole Size Y: 0.2 mm
Verified computed result:
  • Copper outer size: 0.4 × 0.4 mm
  • Drill/hole: 0.2 × 0.2 mm
Important details for the other agent:
  • Target the generated through-hole child node, including the .throughHole.0-0 suffix—not just the base object UUID.
  • Use sizeX and sizeY; the scalar size field did not produce the desired result here.
  • Use holeSizeX and holeSizeY; the scalar holeSize field was also ineffective in this workflow.
  • The via’s inline defaults may still display 0.6/0.3 mm, but the ruleset overrides them and the computed rules should show 0.4/0.2 mm.
Verify vias and BOM
Verify small vias
Check BOM MPNs
Clean obsolete rules
Run final DRC

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Project Specification — Light Pendant V2
Purpose
Design a 25 mm circular wearable pendant PCB for ambient-light tracking over BLE.
User Requirements Captured
  • Board outline: 25 mm diameter circle.
  • Top face: Insight SiP ISP1807 BLE MCU module and ams-OSRAM AS7343 ambient/spectral light sensor.
  • Bottom face: battery connector and compact power circuitry; onboard USB charging has been removed to reduce crowding.
  • Battery: TinyCircuits ASR00011 Li-ion/LiPo pouch, 3.7 V nominal, 70 mAh, micro JST-SH / SHR-02V-S-B battery-side connector.
  • Battery connector: JST SM02B-SRSS-TB(LF)(SN), right-angle/side-entry, 2-pin, 1.0 mm pitch mating connector.
  • Charging interface: two exposed external charger pads, TP5=BAT+ and TP6=GND, for connection to an off-board single-cell LiPo charger.
  • Programming: 4 SWD points in one clearly ordered edge-accessible row: SWDIO, SWDCLK, 3V3, GND.
  • Key layout constraint: ISP1807 antenna keepout must exclude copper, traces, vias, components, battery metal, connector metal, and ground pour on all layers in the antenna zone.
Architecture
Diagram



  
    
  
  
    
  





















External node_1S LiPo charger pads TP5/TP6
1S LiPo BAT rail
JST SH battery connector
MCP1703A 3.3V LDO
AP2112K 1.8V LDO
ISP1807 BLE module
TXS0102 I2C level shifter B-side
AS7343 spectral sensor
4 SWD pads
Selected Parts

Table

RefPartPurposeNotes
U1ISP1807-LR-RSBLE MCU modulenRF52840-based, 1.7-3.6 V VCC_NRF, integrated antenna/clocks/DC-DC; VBUS tied to GND because USB is unused
U2AS7343-DLGMAmbient/spectral light sensorRequires 1.7-1.98 V VDD, I2C address 0x39
U4MCP1703Ax-330xxTT3.3 V LDOLow-Iq supply for ISP1807 and 3.3 V I2C side
U5AP2112K-1.8TRG11.8 V LDOSupplies AS7343 and 1.8 V I2C side
U6TXS0102DCUI2C level shifterA-side 1V8, B-side 3V3; internal 10 kΩ pullups
J2SM02B-SRSS-TB(LF)(SN)Battery connectorExact right-angle JST SH mating connector for TinyCircuits ASR00011
TP51.25 mm SMD test pointExternal charger BAT+ padConnect only to an appropriate off-board single-cell LiPo charger
TP61.25 mm SMD test pointExternal charger GND padReturn pad for external charger
Key Nets

Table

NetFunction
BATLiPo positive rail, J2 pin 1, TP5, LDO inputs, battery sense divider
GNDCommon return, J2 pin 2, TP6, SWD GND pad, ISP1807 VBUS tie-down
3V3ISP1807 VCC_NRF, TXS0102 VCCB, SWD 3V3 pad
1V8AS7343 VDD and TXS0102 VCCA/OE
I2C_SCL_3V3 / I2C_SDA_3V3ISP1807 side of I2C bus
I2C_SCL_1V8 / I2C_SDA_1V8AS7343 side of I2C bus
BAT_SENSE1 MΩ / 1 MΩ divider to ISP1807 P0_02/AIN0
RF_ANT_LINKRequired ISP1807 OUT_ANT to OUT_MOD connection
Important Design Decisions
  • Onboard USB-C charging was removed to simplify the 25 mm layout and reduce bottom-side crowding.
  • Charging is now intentionally external: TP5 and TP6 expose BAT/GND for an off-board 4.20 V single-cell LiPo charger suitable for the 70 mAh ASR00011.
  • AS7343 is not a 3.3 V sensor; the schematic includes a 1.8 V rail and I2C level shifting.
  • ISP1807 VBUS is tied to GND because USB is not used.
  • Verify whether the selected ASR00011 assembly includes protection; if not, add cell protection or use a protected pack.
  • SWD is implemented as exactly 4 pads per request; adding RESET as a fifth pad remains recommended for recovery.
Layout Constraints for Next Phase
  • 25 mm circular outline.
  • Place ISP1807 at the edge with antenna facing outward.
  • Enforce ISP1807 antenna no-metal keepout: minimum 18 mm x 4 mm zone to board edge, all layers.
  • Keep JST connector, charger pads, battery pouch, pendant metal ring/chain, vias, and copper away from antenna keepout.
  • Place AS7343 top-side with a clear optical aperture and no tall nearby parts or status LED light leakage.
  • Place J2 and TP5/TP6 where they are accessible for battery connection and external charging, preferably bottom-side if mechanically convenient.
  • Place SWD pads in a single ordered row near an edge: SWDIO, SWDCLK, 3V3, GND.
Open Items
  • Confirm ASR00011 protection status and final cable polarity against the production drawing.
  • Select/define the external charger fixture or cable that connects to TP5/TP6.
  • Verify ISP1807 module certification identifiers and integration conditions for FCC/CE documentation.

  • Purpose

  • User Requirements Captured

  • Architecture

  • Selected Parts

  • Key Nets

  • Important Design Decisions

  • Layout Constraints for Next Phase

  • Open Items

Light Pendant V2

Light Pendant V2 thumbnail
25 mm circular BLE wearable pendant for ambient-light tracking using an ISP1807 module, AS7343 sensor, USB-C LiPo charging, and SWD programming pads.

Properties

Properties describe core aspects of the project.

Pricing & Availability

Distributor

Qty 1

Arrow

$5.86–$6.12

Digi-Key

$0.00

HQonline

$0.35

LCSC

$14.68

Mouser

$9.48

TME

$3.40–$3.42

Verical

$0.23–$0.64

Controls