# FJ Compass Module (2nd Attempt)
## Description
USB-C Digital Compass Module with STM32, HMC5883L, TM1637 Display, and Enhanced Power Protection (JLCPCB-Ready)
## Project Details
- **Owner:** brooks-tast-2025-11-17
- **Created:** 11/21/2025
- **Last Updated:** 12/5/2025
- **Visibility:** Public
- **Board Outline Dimensions:** 90.2mm × 35.4mm
- **Board Outline Width (mm):** 90.2mm
- **Power Plane Layers:** Layer 2: GND plane; Layer 3: 3.3V plane
- **Board Outline Height (mm):** 35.4mm
- **Stackup:** Standard 4 Layer
- **System Architecture:** graph LR
subgraph Power Subsystem
USB_C[USB-C Connector] --> Input_Protection[Input Protection]
Input_Protection --> Regulator[3.3V Regulator]
end
subgraph Core Subsystem
Regulator --> MCU[Microcontroller]
MCU --> Magnetometer[I2C Magnetometer]
end
subgraph Display Subsystem
MCU -->|Control Interface| DisplayDriver[Display Driver ICs]
DisplayDriver --> SevenSeg[3×7-Segment Displays]
end
subgraph UI Subsystem
MCU --> Potentiometer[Brightness Pot w/ Switch]
MCU --> StatusLED[Status LED]
MCU --> ProgHeader[Programming Header]
end
subgraph Mechanical
Board --> MountHoles[4× Mounting Holes]
end
- **Display Module Width:** 12.8mm
- **Copies:** 1
## Key Components
### D1 — [TPD4E05U06DQAR](https://www.flux.ai/jharwinflux/tpd4e05u06dqar~rl.md)
- Role: Protection
- License: https://creativecommons.org/licenses/by/4.0/
- Manufacturer Part Number: TPD4E05U06DQAR
- Datasheet URL: https://www.ti.com/lit/ds/symlink/tpd4e05u06.pdf
- Manufacturer Name: Texas Instruments Inc.
- Role Details: ESD protection for USB_DP line
- Part Type: Diode
**Pins:**
- D1- [pin 2]
- D1+ [pin 1]
- D2- [pin 5]
- D2+ [pin 4]
- GND_1 [pin 3]
- GND_2 [pin 8]
- NC_1 [pin 6]
- NC_2 [pin 7]
- NC_3 [pin 9]
- NC_4 [pin 10]
### D2 — [LTST-C190KRKT](https://www.flux.ai/adrian95/ltst-c190krkt~3pw.md)
- Datasheet URL: https://optoelectronics.liteon.com/upload/download/DS-22-99-0151/LTST-C190KRKT.pdf
- Manufacturer Name: Lite-On Inc.
- Role Details: Status indicator for MCU (power/status)
- JLCPCB Part Class: Basic Part
- Manufacturer Part Number: LTST-C190KRKT
- Part Type: LED
- Role: LED
- License: https://creativecommons.org/licenses/by/4.0/
- Package: D_0603_1608Metric
**Pins:**
- A [pin 2]
- K [pin 1]
### D2 — [TPD4E05U06DQAR](https://www.flux.ai/jharwinflux/tpd4e05u06dqar~rl.md)
- Datasheet URL: https://www.ti.com/lit/ds/symlink/tpd4e05u06.pdf
- Manufacturer Name: Texas Instruments Inc.
- Part Type: Diode
- Role: Protection
- Role Details: ESD protection for USB_DM line
- Manufacturer Part Number: TPD4E05U06DQAR
- License: https://creativecommons.org/licenses/by/4.0/
**Pins:**
- D1- [pin 2]
- D1+ [pin 1]
- D2- [pin 5]
- D2+ [pin 4]
- GND_1 [pin 3]
- GND_2 [pin 8]
- NC_1 [pin 6]
- NC_2 [pin 7]
- NC_3 [pin 9]
- NC_4 [pin 10]
### D3 — [Diode_THT_P10.16mm_Horizontal](https://www.flux.ai/jecstronic/diodethtp1016mmhorizontal~6z.md)
- Part Type: Diode
**Pins:**
- A
- K
### DS1 — [HDSP-5503](https://www.flux.ai/adrian95/hdsp-5503~s80.md)
- Role: Display Device
- Role Details: 1-inch red 7-segment LED display module for compass digits
- JLCPCB Part Class: Extended Part
- Datasheet URL: https://www.mouser.com/datasheet/2/678/AV02_1107EN_2022_12_08-1827817.pdf
- License: https://creativecommons.org/licenses/by/4.0/
- Manufacturer Name: Broadcom Limited
- Part Type: Display Module
- Manufacturer Part Number: HDSP-5503
**Pins:**
- ANODE_A [pin 7]
- ANODE_B [pin 6]
- ANODE_C [pin 4]
- ANODE_D [pin 2]
- ANODE_DP [pin 5]
- ANODE_E [pin 1]
- ANODE_F [pin 9]
- ANODE_G [pin 10]
- COMMON_CATHODE_1 [pin 3]
- COMMON_CATHODE_2 [pin 8]
### F1 — [0805L110WR](https://www.flux.ai/adrian95/0805l110wr~h3i.md)
- License: https://creativecommons.org/licenses/by/4.0/
- Role: Protection
- Part Type: Protection
- Manufacturer Part Number: 0805L110WR
- Role Details: Resettable fuse on USB-C VBUS line for overcurrent
- Datasheet URL: https://www.littelfuse.com/media?resourcetype=datasheets&itemid=3b1fa5dc-24aa-4363-b543-edb057c2fffa&filename=littelfuse_ptc_0805l_datasheet.pdf
- Manufacturer Name: Littelfuse Inc.
**Pins:**
- P1 [pin 1]
- P2 [pin 2]
### J1 — [TYPE-C-16M-0243MD](https://www.flux.ai/lcsc/type-c-16m-0243md~qm.md)
- Role: Connector
- Package or Case Code: USB-C-SMD_TYPE-611-T3-W
- Manufacturer Name: USAKRO(美韩)
- LCSC Part Number: C2798172
- Role Details: USB-C power input
- JLCPCB Part Class: Extended Part
- Part Type: USB Connectors
- Manufacturer Part Number: TYPE-C-16M-0243MD
**Pins:**
- 17 [pin 17]
- 18 [pin 18]
- 19 [pin 19]
- 20 [pin 20]
- CC1 [pin A5]
- CC2 [pin B5]
- DN1 [pin A7]
- DN2 [pin B7]
- DP1 [pin A6]
- DP2 [pin B6]
- GND [pin A1]
- GND [pin A12]
- GND [pin B1]
- GND [pin B12]
- SBU1 [pin A8]
- SBU2 [pin B8]
- VBUS [pin A9]
- VBUS [pin B4]
- VBUS [pin B9]
- VBUS [pin A4]
### U1 — [STM32G030K6T6](https://www.flux.ai/lcsc/stm32g030k6t6~a79f.md)
- Datasheet URL: https://storage.googleapis.com/graviton-electric-symbols/document_assets/lcsc/2304140030_STMicroelectronics-STM32G030K6T6_C529331.pdf
- Operating Temperature: -40 to 85°C
- Manufacturer Name: ST(意法半导体)
- IC Type: Microcontroller
- Package or Case Code: LQFP-32_L7.0-W7.0-P0.80-LS9.0-BL
- Frequency: 64MHz
- Role Details: Main MCU for compass processing, I2C, PWM control
- Operating Voltage: 2 ~ 3.6V
- JLCPCB Part Class: Extended Part
- Part Type: ST Microelectronics
- Role: Microcontroller
- LCSC Part Number: C529331
- Manufacturer Part Number: STM32G030K6T6
- Product Info Url: https://lcsc.com/product-detail/ST-Microelectronics_STMicroelectronics-STM32G030K6T6_C529331.html
**Pins:**
- NRST [pin 6]
- PA0 [pin 7]
- PA1 [pin 8]
- PA10 [pin 21]
- PA11[PA9] [pin 22]
- PA12[PA10] [pin 23]
- PA13 [pin 24]
- PA14-BOOT0 [pin 25]
- PA15 [pin 26]
- PA2 [pin 9]
- PA3 [pin 10]
- PA4 [pin 11]
- PA5 [pin 12]
- PA6 [pin 13]
- PA7 [pin 14]
- PA8 [pin 18]
- PA9 [pin 19]
- PB0 [pin 15]
- PB1 [pin 16]
- PB2 [pin 17]
- PB3 [pin 27]
- PB4 [pin 28]
- PB5 [pin 29]
- PB6 [pin 30]
- PB7 [pin 31]
- PB8 [pin 32]
- PB9 [pin 1]
- PC14-OSC32IN [pin 2]
- PC15-OSC32OUT [pin 3]
- PC6 [pin 20]
- VDD/VDDA [pin 4]
- VSS/VSSA [pin 5]
### U2 — [TM1637](https://www.flux.ai/lcsc/tm1637~5ebn.md)
- Manufacturer Part Number: TM1637
- LCSC Part Number: C2962580
- Manufacturer Name: TM(天微)
- Package or Case Code: SOP-20_L12.8-W7.5-P1.27-LS10.4-BL
- JLCPCB Part Class: Extended Part
- Role Details: 7-segment display driver IC for each digit module
- Role: Display Device
**Pins:**
- CLK [pin 18]
- DIO [pin 17]
- GND [pin 1]
- GRID1 [pin 15]
- GRID2 [pin 14]
- GRID3 [pin 13]
- GRID4 [pin 12]
- GRID5 [pin 11]
- GRID6 [pin 10]
- K1 [pin 19]
- K2 [pin 20]
- SEG1/KS1 [pin 2]
- SEG2/KS2 [pin 3]
- SEG3/KS3 [pin 4]
- SEG4/KS4 [pin 5]
- SEG5/KS5 [pin 6]
- SEG6/KS6 [pin 7]
- SEG7/KS7 [pin 8]
- SEG8/KS8 [pin 9]
- VDD [pin 16]
### U6 — [AMS1117-3.3](https://www.flux.ai/vasy_skral/ams1117-33~34.md)
- Datasheet URL: http://www.advanced-monolithic.com/pdf/ds1117.pdf
- Part Type: Integrated Circuit
- Manufacturer Part Number: AMS1117-3.3
- JLCPCB Part Class: Extended Part
- Symbol Style: Parametric
- Role: Power Management
- Manufacturer Name: AMS
- Role Details: 5V to 3.3V LDO regulator for MCU and peripherals
- License: https://creativecommons.org/licenses/by/4.0/
**Pins:**
- GND [pin 1]
- TAB(VOUT) [pin 4]
- VIN [pin 3]
- VOUT [pin 2]
### U6 — [HMC5883L-TR](https://www.flux.ai/adrian95/hmc5883l-tr~f5a.md)
- Part Type: Sensor
- Manufacturer Part Number: HMC5883L-TR
- Datasheet URL: https://mm.digikey.com/Volume0/opasdata/d220001/medias/docus/635/HMC5883L.pdf
- Manufacturer Name: Honeywell Aerospace
- JLCPCB Part Class: Extended Part
- Role: Sensor
- Role Details: 3-axis I2C magnetometer
- License: https://creativecommons.org/licenses/by/4.0/
**Pins:**
- C1 [pin 10]
- DRDY [pin 15]
- GND_1 [pin 9]
- GND_2 [pin 11]
- NC_1 [pin 3]
- NC_2 [pin 5]
- NC_3 [pin 6]
- NC_4 [pin 7]
- NC_5 [pin 14]
- S1 [pin 4]
- SCL [pin 1]
- SDA [pin 16]
- SETC [pin 12]
- SETP [pin 8]
- VDD [pin 2]
- VDDIO [pin 13]
### VR1 — [PDB181-K420K-103B](https://www.flux.ai/jecstronic/pdb181-k420k-103b~evz.md)
- Datasheet URL: https://www.bourns.com/docs/Product-Datasheets/PDB18.pdf
- Manufacturer Part Number: PDB181-K420K-103B
- Resistance: 10kΩ
- License: https://creativecommons.org/licenses/by/4.0/
- JLCPCB Part Class: Extended Part
- Part Type: Potentiometer
- Package: R_POT_PV36P
- Role Details: Brightness control input to MCU, integrated switch for off state
- Role: Voltage Division
- Manufacturer Name: Bourns Inc.
**Pins:**
- CCW [pin 1]
- CW [pin 3]
- WIPER [pin 2]
*The full schematic, PCB layout, bill of materials, and interactive design are available at [https://www.flux.ai/brooks-tast-2025-11-17/fj-compass-module-2nd-attempt~mp](https://www.flux.ai/brooks-tast-2025-11-17/fj-compass-module-2nd-attempt~mp).*
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*Generated from [https://www.flux.ai/brooks-tast-2025-11-17/fj-compass-module-2nd-attempt~mp](https://www.flux.ai/brooks-tast-2025-11-17/fj-compass-module-2nd-attempt~mp)*