# FJ Cruiser Solar Compass Display ## Description Dashboard-mounted solar-assisted automotive compass for a Toyota FJ Cruiser using three amber 7-segment displays, an I2C magnetometer, MCU/display driver control, LiPo energy storage, and a dimmer knob with off switch. ## Project Details - **Owner:** brooks - **Created:** 4/27/2026 - **Last Updated:** 4/27/2026 - **Visibility:** Public ## Key Components ### D1 — [SMBJ16A-13-F](https://www.flux.ai/lcsc/smbj16a-13-f~dx1g.md) - Package or Case Code: SMB_L4.6-W3.6-LS5.3-RD - Manufacturer Name: DIODES(美台) - Part Type: TVS - JLCPCB Part Class: Extended Part - Datasheet URL: https://storage.googleapis.com/graviton-electric-symbols/document_assets/lcsc/2304140030_Diodes-Incorporated-SMBJ16A-13-F_C135050.pdf - LCSC Part Number: C135050 - Role Details: Input transient clamp after PTC fuse for dashboard automotive environment - Package: SMB - Role: TVS Protection - Manufacturer Part Number: SMBJ16A-13-F - Product Info Url: https://lcsc.com/product-detail/TVS_DIODES_SMBJ16A-13-F_SMBJ16A-13-F_C135050.html **Pins:** - A [pin 2] - K [pin 1] ### D2 — [1N5819HW-7-F](https://www.flux.ai/jecstronic/1n5819hw-7-f~x5v.md) - Package: SOD-123 - Part Type: Diode - Manufacturer Name: Diodes Incorporated - Role Details: Schottky diode between protected solar input and charger input - Datasheet URL: https://www.diodes.com/assets/Datasheets/ds30217.pdf - Role: Reverse Protection - License: https://creativecommons.org/licenses/by/4.0/ - Manufacturer Part Number: 1N5819HW-7-F **Pins:** - A [pin 2] - K [pin 1] ### DISP1 — [LTS-5503AE](https://www.flux.ai/adrian95/lts-5503ae~4gb.md) - License: https://creativecommons.org/licenses/by/4.0/ - Manufacturer Part Number: LTS-5503AE - Manufacturer Name: Lite-On Inc. - Package: 10-DIP 0.600in - Role Details: Lite-On orange-red common-cathode single digit display, first compass character; replaces footprint-problem 0.3in placeholder - Datasheet URL: https://mm.digikey.com/Volume0/opasdata/d220001/medias/docus/526/LTS-5x01_3A_LTD5x21_23A_LTC-56_753x-01.pdf - Part Type: LED - Role: 7-Segment Display **Pins:** - ANODE_A [pin 7] - ANODE_B [pin 6] - ANODE_C [pin 4] - ANODE_D [pin 2] - ANODE_D.P. [pin 5] - ANODE_E [pin 1] - ANODE_F [pin 9] - ANODE_G [pin 10] - COMMON_CATHODE_1 [pin 3] - COMMON_CATHODE_2 [pin 8] ### DISP2 — [LTS-5503AE](https://www.flux.ai/adrian95/lts-5503ae~4gb.md) - Role Details: Lite-On orange-red common-cathode single digit display, second compass character; replaces footprint-problem 0.3in placeholder - Role: 7-Segment Display - License: https://creativecommons.org/licenses/by/4.0/ - Manufacturer Part Number: LTS-5503AE - Manufacturer Name: Lite-On Inc. - Package: 10-DIP 0.600in - Part Type: LED - Datasheet URL: https://mm.digikey.com/Volume0/opasdata/d220001/medias/docus/526/LTS-5x01_3A_LTD5x21_23A_LTC-56_753x-01.pdf **Pins:** - ANODE_A [pin 7] - ANODE_B [pin 6] - ANODE_C [pin 4] - ANODE_D [pin 2] - ANODE_D.P. [pin 5] - ANODE_E [pin 1] - ANODE_F [pin 9] - ANODE_G [pin 10] - COMMON_CATHODE_1 [pin 3] - COMMON_CATHODE_2 [pin 8] ### DISP3 — [LTS-5503AE](https://www.flux.ai/adrian95/lts-5503ae~4gb.md) - Role: 7-Segment Display - Manufacturer Name: Lite-On Inc. - Package: 10-DIP 0.600in - License: https://creativecommons.org/licenses/by/4.0/ - Manufacturer Part Number: LTS-5503AE - Role Details: Lite-On orange-red common-cathode single digit display, third compass character; replaces footprint-problem 0.3in placeholder - Datasheet URL: https://mm.digikey.com/Volume0/opasdata/d220001/medias/docus/526/LTS-5x01_3A_LTD5x21_23A_LTC-56_753x-01.pdf - Part Type: LED **Pins:** - ANODE_A [pin 7] - ANODE_B [pin 6] - ANODE_C [pin 4] - ANODE_D [pin 2] - ANODE_D.P. [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 — [MF-MSMF050-2](https://www.flux.ai/adrian95/mf-msmf050-2~8fg.md) - Manufacturer Name: Bourns Inc. - Role: Input Fuse - Manufacturer Part Number: MF-MSMF050-2 - License: https://creativecommons.org/licenses/by/4.0/ - Package: 1812 - Datasheet URL: https://www.bourns.com/docs/product-datasheets/mf-msmf.pdf - Part Type: Fuse - Role Details: 500mA resettable PTC before TVS clamp and charger input **Pins:** - P1 [pin 1] - P2 [pin 2] ### J1 — [1546215-2](https://www.flux.ai/adrian95/1546215-2~xhw.md) - Manufacturer Name: TE Connectivity AMP Connectors - Part Type: Connector - Role Details: Two-wire input from small dashboard solar panel - Datasheet URL: https://www.te.com/usa-en/product-1546215-2.datasheet.pdf - License: https://creativecommons.org/licenses/by/4.0/ - Role: Solar Input Connector - Package: 2.54mm THT Terminal Block - Manufacturer Part Number: 1546215-2 **Pins:** - 1 [pin 1] - 2 [pin 2] ### J2 — [B2B-PH-K-S](https://www.flux.ai/adrian95/b2b-ph-k-s~fx.md) - Role: Battery Connector - Role Details: JST-PH connector for protected single-cell LiPo pack - Manufacturer Part Number: B2B-PH-K-S - Package: JST_B2B-PH-K-S - Part Type: Connector - Package or Case Code: JST_B2B-PH-K-S - License: https://creativecommons.org/licenses/by/4.0/ - Manufacturer Name: JST - Datasheet URL: https://www.jst-mfg.com/product/pdf/eng/ePH.pdf **Pins:** - 1 [pin 1] - 2 [pin 2] ### J3 — [3220-10-0300-00](https://www.flux.ai/adrian95/3220-10-0300-00~4yk.md) - Manufacturer Name: CNC Tech - Role Details: Programming and debug access for ATSAMD21 firmware - Datasheet URL: https://www.cnctech.us/pdfs/3220-XX-0300-00_.pdf - Package: 2x5 1.27mm SMD Header - Package or Case Code: CNC_3220-10-0300-00 - Manufacturer Part Number: 3220-10-0300-00 - Role: SWD Debug Header - Part Type: Connector **Pins:** - 1 [pin 1] - 10 [pin 10] - 2 [pin 2] - 3 [pin 3] - 4 [pin 4] - 5 [pin 5] - 6 [pin 6] - 7 [pin 7] - 8 [pin 8] - 9 [pin 9] ### RV1 — [PTR902-2015K-A104](https://www.flux.ai/jecstronic/ptr902-2015k-a104~709.md) - Manufacturer Name: Texas Instruments Inc. - Package: Through Hole - Role: Dimmer Off Knob - Datasheet URL: https://www.bourns.com/docs/Product-Datasheets/PTR90.pdf - Part Type: Potentiometer - Manufacturer Part Number: PTR902-2015K-A104 - License: https://creativecommons.org/licenses/by/4.0/ - Role Details: Rotary potentiometer with integrated SPST switch; potentiometer feeds MCU ADC for brightness, switch gates system enable/off **Pins:** - R1_1 [pin 1] - R1_2 [pin 2] - R1_3 [pin 3] - R2_1 [pin 4] - R2_2 [pin 5] - R2_3 [pin 6] - SW_1 [pin 7] - SW_2 [pin 8] ### U1 — [ATSAMD21G18A-AU](https://www.flux.ai/adrian95/atsamd21g18a-au~p9s.md) - Package: TQFP-48 - Role Details: 3.3V MCU for compass heading calculation, I2C sensor/display control, ADC dimmer input, SWD programming - Part Type: Microcontroller - Role: MCU - License: https://creativecommons.org/licenses/by/4.0/ - Manufacturer Part Number: ATSAMD21G18A-AU - Datasheet URL: https://ww1.microchip.com/downloads/en/DeviceDoc/SAM-D21-DA1-Family-Data-Sheet-DS40001882H.pdf - Manufacturer Name: Microchip Technology **Pins:** - ~RESETN [pin 40] - GND1 [pin 18] - GND2 [pin 35] - GND3 [pin 42] - GNDANA [pin 5] - PA00 [pin 1] - PA01 [pin 2] - PA02 [pin 3] - PA03 [pin 4] - PA04 [pin 9] - PA05 [pin 10] - PA06 [pin 11] - PA07 [pin 12] - PA08 [pin 13] - PA09 [pin 14] - PA10 [pin 15] - PA11 [pin 16] - PA12 [pin 21] - PA13 [pin 22] - PA14 [pin 23] - PA15 [pin 24] - PA16 [pin 25] - PA17 [pin 26] - PA18 [pin 27] - PA19 [pin 28] - PA20 [pin 29] - PA21 [pin 30] - PA22 [pin 31] - PA23 [pin 32] - PA24 [pin 33] - PA25 [pin 34] - PA27 [pin 39] - PA28 [pin 41] - PA30 [pin 45] - PA31 [pin 46] - PB02 [pin 47] - PB03 [pin 48] - PB08 [pin 7] - PB09 [pin 8] - PB10 [pin 19] - PB11 [pin 20] - PB22 [pin 37] - PB23 [pin 38] - VDDANA [pin 6] - VDDCORE [pin 43] - VDDIN [pin 44] - VDDIO1 [pin 17] - VDDIO2 [pin 36] ### U2 — [LIS3MDL](https://www.flux.ai/kicad-part-library/lis3mdl~yb6.md) - Package or Case Code: LGA-12_2x2mm_P0.5mm - Manufacturer Part Number: LIS3MDL - Package: LGA-12 - Role: Compass Sensor - Role Details: I2C 3-axis magnetometer placed away from display current paths and ferrous hardware - Datasheet URL: https://www.st.com/resource/en/datasheet/lis3mdl.pdf **Pins:** - ~{CS} [pin 10] - C1 [pin 4] - DRDY [pin 8] - GND [pin 12] - GND [pin 3] - GND [pin 2] - INT [pin 7] - SCL/SPC [pin 1] - SDA/SDI/SDO [pin 11] - SDO/SA1 [pin 9] - Vdd [pin 5] - Vdd_IO [pin 6] ### U3 — [IS31FL3731-SALS2-TR](https://www.flux.ai/lcsc/is31fl3731-sals2-tr~tahq.md) - LCSC Part Number: C2940545 - Manufacturer Part Number: IS31FL3731-SALS2-TR - Manufacturer Name: ISSI(美国芯成) - Package: SSOP-28 - Role Details: I2C LED matrix driver for amber 7-segment display segments and digit commons - Package or Case Code: SSOP-28_L10.2-W5.3-P0.65-LS7.8-BL - JLCPCB Part Class: Extended Part - Role: LED Display Driver **Pins:** - AD [pin 18] - C_FILT [pin 16] - CA1 [pin 21] - CA2 [pin 22] - CA3 [pin 23] - CA4 [pin 24] - CA5 [pin 25] - CA6 [pin 26] - CA7 [pin 27] - CA8 [pin 28] - CA9 [pin 1] - CB1 [pin 7] - CB2 [pin 8] - CB3 [pin 9] - CB4 [pin 10] - CB5 [pin 11] - CB6 [pin 12] - CB7 [pin 13] - CB8 [pin 14] - CB9 [pin 15] - GND [pin 5] - IN [pin 17] - INTB [pin 4] - R_EXT [pin 6] - SCL [pin 20] - SDA [pin 19] - SDB [pin 3] - VCC [pin 2] ### U4 — [BQ25185DLHR](https://www.flux.ai/adrian95/bq25185dlhr~hvy.md) - Manufacturer Part Number: BQ25185DLHR - Symbol Style: Legacy - License: https://creativecommons.org/licenses/by/4.0/ - Manufacturer Name: Texas Instruments - Package: 10-WSON - Role Details: Single-cell LiPo charger for small solar panel input and battery-backed dashboard operation - Datasheet URL: https://www.ti.com/lit/ds/symlink/bq25185.pdf?ts=1701339761812&ref_url=https%253A%252F%252Fwww.ti.com%252Fproduct%252FBQ25185 - Role: Solar LiPo Charger - Part Type: Integrated Circuits **Pins:** - ~CE [pin 4] - BAT [pin 2] - EP [pin 11] - GND [pin 5] - ILIM/VSET [pin 7] - IN [pin 10] - ISET [pin 8] - STAT1 [pin 9] - STAT2 [pin 3] - SYS [pin 1] - TS/MR [pin 6] ### U5 — [MCP1703Ax-330xxTT](https://www.flux.ai/kicad-part-library/mcp1703ax-330xxtt~9wn.md) - Role Details: Low-Iq 3.3V LDO fed from battery/system rail - Package: SOT-23 - Package or Case Code: SOT-23 - Manufacturer Part Number: MCP1703Ax-330xxTT - Datasheet URL: http://ww1.microchip.com/downloads/en/DeviceDoc/20005122B.pdf - Manufacturer Name: Microchip Technology Inc. - Role: 3.3V Regulator **Pins:** - GND [pin 1] - VI [pin 3] - VO [pin 2] *The full schematic, PCB layout, bill of materials, and interactive design are available at [https://www.flux.ai/brooks/fj-cruiser-solar-compass-display~z5](https://www.flux.ai/brooks/fj-cruiser-solar-compass-display~z5).* --- *Generated from [https://www.flux.ai/brooks/fj-cruiser-solar-compass-display~z5](https://www.flux.ai/brooks/fj-cruiser-solar-compass-display~z5)*