# starter ec7b be93 ## Description USB-C Digital Compass Module with STM32, HMC5883L, TM1637 Display, and Enhanced Power Protection (JLCPCB-Ready) ## Project Details - **Owner:** dacre - **Created:** 3/16/2026 - **Last Updated:** 3/16/2026 - **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 ## Key Components ### BT1 — [968](https://www.flux.ai/adrian95/968.md) - Role: Power Input - Datasheet URL: https://www.keyelco.com/userAssets/file/M65p31.pdf - Manufacturer Name: Keystone - License: https://creativecommons.org/licenses/by/4.0/ - Manufacturer Part Number: 968 - Package or Case Code: BAT_968 - Role Details: 9V battery snap connector, PCB mount - Part Type: Battery Connector - Package: THT - Pin Type: Power Output **Pins:** - N [pin N] - P [pin P] ### LED1 — [TLHR5400](https://www.flux.ai/jecstronic/tlhr5400.md) - License: https://creativecommons.org/licenses/by/4.0/ - Package: THT 5mm - Part Type: LED - Datasheet URL: https://www.verical.com/datasheet/vishay-low-power-led--below-100ma--TLHR5400-402522.pdf - Manufacturer Name: Vishay Semiconductor Opto Division - Manufacturer Part Number: TLHR5400 - Role: Indicator - Role Details: Red LED blinker output **Pins:** - A [pin 2] - K [pin 1] ### S1 — [200USP9T1A1M2RE](https://www.flux.ai/jecstronic/200usp9t1a1m2re.md) - License: https://creativecommons.org/licenses/by/4.0/ - Part Type: Switch - Pin Type: Passive - Datasheet URL: https://eswitch.wpengine.com/wp-content/uploads/2022/06/200U.pdf - Role Details: SPST on/off switch in series with 9V battery - Package: THT - Manufacturer Part Number: 200USP9T1A1M2RE - Manufacturer Name: E-Switch - Role: Power Switch **Pins:** - COM [pin 6] - NO [pin 4] - SUPPORT_TERMINAL_1 [pin 1] - SUPPORT_TERMINAL_2 [pin 3] ### SW1 — [SWITCH-PUSH-6mm-H5mm-4pin](https://www.flux.ai/baronunread/switch-push-6mm-h5mm-4pin.md) - License: https://creativecommons.org/licenses/by/4.0/ - Package: THT - Role: Power Switch - Role Details: On/off switch in series with 9V battery - Part Type: Switch **Pins:** - 1-1 [pin 1-1] - 1-2 [pin 1-2] - 2-1 [pin 2-1] - 2-2 [pin 2-2] ### U1 — [NE555P - 518340](https://www.flux.ai/kicad-part-library/ne555p-518340.md) - Manufacturer Name: Texas Instruments Inc. - Role Details: 555 timer in astable mode, ~1 Hz - Package or Case Code: DIP-8_W7.62mm - Role: Timer - Package: DIP-8_W7.62mm - Manufacturer Part Number: NE555P - Datasheet URL: http://www.ti.com/lit/ds/symlink/ne555.pdf **Pins:** - CV [pin 5] - DIS [pin 7] - GND [pin 1] - Q [pin 3] - R [pin 4] - THR [pin 6] - TR [pin 2] - VCC [pin 8] ### U2 — [part-line-desc](https://www.flux.ai/dacre/part-line-desc.md) - Board Outline Height (mm): 35.4mm - Power Plane Layers: Layer 2: GND plane; Layer 3: 3.3V plane - Board Outline Dimensions: 90.2mm × 35.4mm - Stackup: Standard 4 Layer - Display Module Width: 12.8mm - 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 - Board Outline Width (mm): 90.2mm **Pins:** - P1 - P2 *The full schematic, PCB layout, bill of materials, and interactive design are available at [https://www.flux.ai/dacre/starter-ec7b-be93](https://www.flux.ai/dacre/starter-ec7b-be93).* --- *Generated from [https://www.flux.ai/dacre/starter-ec7b-be93](https://www.flux.ai/dacre/starter-ec7b-be93)*