# Fuel Sentinel V1 - Automotive Telematics & Fuel Security ## Description Fuel Sentinel V1 - Automotive Telematics & Fuel Security ## Project Details - **Owner:** yashthapar - **Created:** 3/10/2026 - **Last Updated:** 3/16/2026 - **Visibility:** Public - **System Architecture:** ```mermaid flowchart TD BAT12V["Car battery 12V input"] --> PROT["Reverse diode + TVS"] PROT --> BUCK["LM2596 buck 5V 3A"] BUCK --> RAIL5V["5V rail"] RAIL5V --> ESP["ESP32 DevKit V1"] RAIL5V --> GSM["SIM800L"] RAIL5V --> GPS["NEO-6M"] ESP -->|UART| GSM ESP -->|UART| GPS BAT12V --> IGN["Ignition sense divider"] --> ESP FUEL["Fuel sender line"] --> OPAMP["LM358 follower (IGN on)"] --> ESP ESP --> PULLUP["3.3V pullup via Schottky (IGN off)"] --> FUEL ESP --> TAMP["Tamper switch header"] RAIL5V --> GND["Common GND"] BAT12V --> GND ESP --> GND GSM --> GND GPS --> GND OPAMP --> GND ``` ## Key Components ### D1 — [1N4007RLG](https://www.flux.ai/jecstronic/1n4007rlg.md) - Datasheet URL: https://www.onsemi.com/pdf/datasheet/1n4001-d.pdf - Part Type: Diode - Manufacturer Part Number: 1N4007RLG - Manufacturer Name: onsemi - Role Details: Reverse polarity series diode on 12V input - Package: DO-41 - Role: Protection - License: https://creativecommons.org/licenses/by/4.0/ **Pins:** - anode [pin 2] - cathode [pin 1] ### D3 — [SM6T22A](https://www.flux.ai/jecstronic/sm6t22a.md) - Package: SMB - Manufacturer Name: STMicroelectronics - Role Details: TVS clamp across 12V input - License: https://creativecommons.org/licenses/by/4.0/ - Manufacturer Part Number: SM6T22A - Part Type: Diode - Datasheet URL: https://www.mouser.com/datasheet/2/389/sm6t100a-1916590.pdf - Role: Protection **Pins:** - A [pin 2] - K [pin 1] ### D6 — [BAT54J,115](https://www.flux.ai/lcsc/bat54jc115.md) - Role: Protection - Package: SOD-323F - Manufacturer Name: Nexperia(安世) - Datasheet URL: https://storage.googleapis.com/graviton-electric-symbols/document_assets/lcsc/2410010302_Nexperia-BAT54J-115_C130415.pdf - Role Details: Prevents backfeed from fuel line to 3.3V via pullup - JLCPCB Part Class: Extended Part - Package or Case Code: SOD-323F_L2.0-W1.6-LS2.5-RD - Part Type: Schottky Barrier Diodes (SBD) - Manufacturer Part Number: BAT54J,115 - LCSC Part Number: C130415 - Product Info Url: https://lcsc.com/product-detail/Schottky-Barrier-Diodes-SBD_Nexperia_BAT54J-115_BAT54J-115_C130415.html **Pins:** - A [pin 2] - C [pin 1] ### J1 — [282837-2](https://www.flux.ai/vasy_skral/282837-2.md) - Manufacturer Part Number: 282837-2 - Manufacturer Name: TE Connectivity AMP Connectors - Datasheet URL: https://www.te.com/commerce/DocumentDelivery/DDEController?Action=srchrtrv&DocNm=282837&DocType=Customer+Drawing&DocLang=English - Role: Connector - Package: THT_5.08mm_2pos - Part Type: Connector - Role Details: 12V battery input **Pins:** - 1 [pin 1] - 2 [pin 2] ### J2 — [282837-2](https://www.flux.ai/vasy_skral/282837-2.md) - Part Type: Connector - Role: Connector - Role Details: Ignition input connector - Manufacturer Name: TE Connectivity AMP Connectors - Datasheet URL: https://www.te.com/commerce/DocumentDelivery/DDEController?Action=srchrtrv&DocNm=282837&DocType=Customer+Drawing&DocLang=English - Manufacturer Part Number: 282837-2 - Package: THT_5.08mm_2pos **Pins:** - 1 [pin 1] - 2 [pin 2] ### J3 — [282837-2](https://www.flux.ai/vasy_skral/282837-2.md) - Package: THT_5.08mm_2pos - Part Type: Connector - Role: Connector - Role Details: Fuel sender signal and return - Datasheet URL: https://www.te.com/commerce/DocumentDelivery/DDEController?Action=srchrtrv&DocNm=282837&DocType=Customer+Drawing&DocLang=English - Manufacturer Name: TE Connectivity AMP Connectors - Manufacturer Part Number: 282837-2 **Pins:** - 1 [pin 1] - 2 [pin 2] ### J4 — [282837-2](https://www.flux.ai/vasy_skral/282837-2.md) - Package: THT_5.08mm_2pos - Datasheet URL: https://www.te.com/commerce/DocumentDelivery/DDEController?Action=srchrtrv&DocNm=282837&DocType=Customer+Drawing&DocLang=English - Manufacturer Name: TE Connectivity AMP Connectors - Manufacturer Part Number: 282837-2 - Role Details: Tamper switch input to GPIO13 - Part Type: Connector - Role: Connector **Pins:** - 1 [pin 1] - 2 [pin 2] ### PS1 — [LM2596 DC-DC buck converter](https://www.flux.ai/vasy_skral/lm2596-dc-dc-buck-converter.md) - License: https://creativecommons.org/licenses/by/4.0/ - Part Type: Integrated Circuit **Pins:** - IN - [pin 2] - IN + [pin 1] - OUT - [pin 3] - OUT + [pin 4] ### U1 — [ESP32-DEVKIT-V1](https://www.flux.ai/jharwinbarrozo/esp32-devkit-v1.md) - Manufacturer Name: Espressif Systems - Symbol Style: Parametric - Manufacturer Part Number: ESP32-DEVKIT-V1 - Datasheet URL: https://www.espressif.com/sites/default/files/documentation/esp32_datasheet_en.pdf - Part Type: Integrated Circuit **Pins:** - 3V3 [pin 1] - D12 [pin 27] - D13 [pin 28] - D14 [pin 26] - D15 [pin 3] - D18 [pin 9] - D19 [pin 10] - D2 [pin 4] - D21 [pin 11] - D22 [pin 14] - D23 [pin 15] - D25 [pin 23] - D26 [pin 24] - D27 [pin 25] - D32 [pin 21] - D33 [pin 22] - D34 [pin 19] - D35 [pin 20] - D4 [pin 5] - D5 [pin 8] - EN [pin 16] - GND [pin 2] - GND_1 [pin 29] - RX0 [pin 12] - RX2 [pin 6] - TX0 [pin 13] - TX2 [pin 7] - VIN [pin 30] - VN [pin 18] - VP [pin 17] ### U2 — [GY-neo6mv2_mod](https://www.flux.ai/shaw/gy-neo6mv2mod.md) **Pins:** - GND [pin 4] - RX [pin 2] - TX [pin 3] - VCC [pin 1] ### U3 — [SIM800L Module](https://www.flux.ai/adrian95/sim800l-module.md) - Part Type: Module - License: https://creativecommons.org/licenses/by/4.0/ - Datasheet URL: https://components101.com/sites/default/files/component_datasheet/SIM800L-Datasheet.pdf - Manufacturer Part Number: SIM800L - Manufacturer Name: Simcom **Pins:** - DTR [pin 11] - GND [pin 6] - MIC- [pin 9] - MIC+ [pin 10] - NET [pin 1] - RING [pin 12] - RST [pin 3] - RXD [pin 4] - SPK- [pin 7] - SPK+ [pin 8] - TXD [pin 5] - VCC [pin 2] ### U4 — [LM358P](https://www.flux.ai/jecstronic/lm358p.md) - Manufacturer Name: Texas Instruments - License: https://creativecommons.org/licenses/by/4.0/ - Part Type: Operational Amplifier (OP-AMP) - Datasheet URL: https://www.ti.com/general/docs/suppproductinfo.tsp?distId=10&gotoUrl=https%3A%2F%2Fwww.ti.com%2Flit%2Fgpn%2Flm358 - Manufacturer Part Number: LM358P **Pins:** - -IN1 [pin 2] - -IN2 [pin 6] - +IN1 [pin 3] - +IN2 [pin 5] - OUT1 [pin 1] - OUT2 [pin 7] - V- [pin 4] - V+ [pin 8] *The full schematic, PCB layout, bill of materials, and interactive design are available at [https://www.flux.ai/yashthapar/fuel-sentinel-v1-automotive-telematics-and-fuel-security](https://www.flux.ai/yashthapar/fuel-sentinel-v1-automotive-telematics-and-fuel-security).* --- *Generated from [https://www.flux.ai/yashthapar/fuel-sentinel-v1-automotive-telematics-and-fuel-security](https://www.flux.ai/yashthapar/fuel-sentinel-v1-automotive-telematics-and-fuel-security)*