# ESP32Tag Dev Board Reference Design ## Description This project is a development tag device that uses the ESP32-WROOM-32E to communicate with other BLE devices. It has a USB-C port for power and data, a voltage regulator for stable operation, and 18650 battery. It also has a CH340C chip for USB to serial conversion.. #referenceDesign #project #ESP32 #ESP32WROOM #RF #WIFI #MCU #tag #18650 #airtag #referenceDesign #simple-embedded #espressif #reference-design ## Project Details - **Owner:** vasy_skral - **Created:** 1/29/2024 - **Last Updated:** 3/4/2026 - **Visibility:** Public - **License:** https://creativecommons.org/licenses/by/4.0/ ## Key Components ### BAT1 — [Battery Holder 1 Cell SMD](https://www.flux.ai/jharwinbarrozo/battery-holder-smd-1-cell-18650.md) - Manufacturer Name: Keystone Electronics - Voltage: 4.2V - Manufacturer Part Number: 1042 - Datasheet URL: https://www.keyelco.com/userAssets/file/M65p27.pdf **Pins:** - NEGATIVE [pin 2] - POSITIVE [pin 1] ### BOOT — [PTS815](https://www.flux.ai/vasy_skral/pts815.md) - Part Type: Switch - Datasheet URL: https://www.ckswitches.com/media/2728/pts815.pdf - Manufacturer Part Number: PTS815 SJM 250 SMTR LFS - Manufacturer Name: C&K **Pins:** - ~1 [pin 1] - ~2 [pin 2] - ~3 [pin 3] - ~4 [pin 4] ### CHG — [LED-0603-Template](https://www.flux.ai/vasy_skral/led-0603-template.md) - License: https://creativecommons.org/licenses/by/4.0/ - Part Type: LED **Pins:** - A [pin 2] - K [pin 1] ### D1 — 1N5819HW-7-F - Datasheet URL: https://www.diodes.com/assets/Datasheets/ds30217.pdf - Manufacturer Name: Diodes Incorporated - License: https://creativecommons.org/licenses/by/4.0/ - Manufacturer Part Number: 1N5819HW-7-F - Part Type: Diode **Pins:** - A [pin 2] - K [pin 1] ### D2 — [WE-TVS-82400102](https://www.flux.ai/vasy_skral/we-tvs-82400102.md) - Datasheet URL: https://katalog.we-online.de/pbs/datasheet/82400102.pdf - Manufacturer Name: Würth Elektronik - Manufacturer Part Number: 82400102 - Part Type: Protection - License: https://creativecommons.org/licenses/by/4.0/ **Pins:** - GND [pin 2] - IO1 [pin 6] - IO1 [pin 1] - IO2 [pin 4] - IO2 [pin 3] - VDD [pin 5] ### IC1 — [CH340C](https://www.flux.ai/vasyl/ch340c.md) - Datasheet URL: https://datasheet.lcsc.com/szlcsc/Jiangsu-Qin-Heng-CH340C_C84681.pdf - Manufacturer Name: Wah - Manufacturer Part Number: CH340C - Part Type: Integrated Circuit **Pins:** - ~CTS [pin 9] - ~DCD [pin 12] - ~DSR [pin 10] - ~DTR [pin 13] - ~RI [pin 11] - ~RTS [pin 14] - GND [pin 1] - NC [pin 7] - NC [pin 8] - R232 [pin 15] - RXD [pin 3] - TXD [pin 2] - UD- [pin 6] - UD+ [pin 5] - V3 [pin 4] - VCC [pin 16] ### PWR — [LED-0805-Template-2](https://www.flux.ai/vasy_skral/led-0805-template-2.md) - License: https://creativecommons.org/licenses/by/4.0/ - Part Type: LED **Pins:** - A [pin 2] - K [pin 1] ### Q1 — BSS138 - Manufacturer Name: onsemi - Manufacturer Part Number: BSS138 - Part Type: Transistor - Datasheet URL: https://www.onsemi.com/pdf/datasheet/bss138-d.pdf **Pins:** - D - G - S ### Q2 — BSS138 - Datasheet URL: https://www.onsemi.com/pdf/datasheet/bss138-d.pdf - Part Type: Transistor - Manufacturer Part Number: BSS138 - Manufacturer Name: onsemi **Pins:** - D - G - S ### Q3 — [SI2333DS-T1-E3](https://www.flux.ai/jecstronic/si2333ds-t1-e3.md) - Datasheet URL: https://www.vishay.com/docs/72023/si2333ds.pdf - Manufacturer Part Number: SI2333DS-T1-E3 - License: https://creativecommons.org/licenses/by/4.0/ - Manufacturer Name: Vishay Siliconix - Part Type: Transistor **Pins:** - D [pin 3] - G [pin 1] - S [pin 2] ### RST — [PTS815](https://www.flux.ai/vasy_skral/pts815.md) - Manufacturer Name: C&K - Manufacturer Part Number: PTS815 SJM 250 SMTR LFS - Datasheet URL: https://www.ckswitches.com/media/2728/pts815.pdf - Part Type: Switch **Pins:** - ~1 [pin 1] - ~2 [pin 2] - ~3 [pin 3] - ~4 [pin 4] ### STB — [LED-0603-Template](https://www.flux.ai/vasy_skral/led-0603-template.md) - Part Type: LED - License: https://creativecommons.org/licenses/by/4.0/ **Pins:** - A [pin 2] - K [pin 1] ### U1 — [AP2112K-3.3TRG1](https://www.flux.ai/vasyl/ap2112k-33trg1.md) - Manufacturer Name: Diodes Incorporated - Datasheet URL: https://www.diodes.com/assets/Datasheets/AP2112.pdf - Part Type: Integrated Circuit - Manufacturer Part Number: AP2112K-3.3TRG1 **Pins:** - EN [pin 3] - GND [pin 2] - VIN [pin 1] - VOUT [pin 5] ### U2 — [ESP32-WROOM-32E](https://www.flux.ai/vasy_skral/esp32-wroom-32e.md) - Manufacturer Part Number: ESP32-WROOM-32E - Part Type: Integrated Circuit - Datasheet URL: https://www.espressif.com/sites/default/files/documentation/esp32-wroom-32e_esp32-wroom-32ue_datasheet_en.pdf - License: https://creativecommons.org/licenses/by/4.0/ - Manufacturer Name: Espressif Systems **Pins:** - GND=> . [pin 15] - EN [pin 3] - GND [pin 38] - GND [pin 39] - GND [pin 1] - IO0 [pin 25] - IO12 [pin 14] - IO13 [pin 16] - IO14 [pin 13] - IO15 [pin 23] - IO16 [pin 27] - IO17 [pin 28] - IO18 [pin 30] - IO19 [pin 31] - IO2 [pin 24] - IO21 [pin 33] - IO22 [pin 36] - IO23 [pin 37] - IO25 [pin 10] - IO26 [pin 11] - IO27 [pin 12] - IO32 [pin 8] - IO33 [pin 9] - IO34 [pin 6] - IO35 [pin 7] - IO4 [pin 26] - IO5 [pin 29] - NC [pin 18] - NC [pin 19] - NC [pin 17] - NC [pin 21] - NC [pin 22] - NC [pin 32] - NC [pin 20] - RXD0/IO3 [pin 34] - SENSOR_VN [pin 5] - SENSOR_VP [pin 4] - TXD0/IO1 [pin 35] - VDD [pin 2] ### U6 — [TP4056](https://www.flux.ai/vasy_skral/tp4056.md) - Manufacturer Part Number: TP4056 - Manufacturer Name: NanJing Top Power ASIC Corp. - Part Type: Integrated Circuit - Datasheet URL: https://dlnmh9ip6v2uc.cloudfront.net/datasheets/Prototyping/TP4056.pdf - License: https://creativecommons.org/licenses/by/4.0/ **Pins:** - ~CHRG [pin 7] - ~STDBY [pin 6] - BAT [pin 5] - CE [pin 8] - EP [pin 9] - GND [pin 3] - PROG [pin 2] - TEMP [pin 1] - VCC [pin 4] ### USB1 — [TYPE-C-31-M-12](https://www.flux.ai/vasy_skral/type-c-31-m-12.md) - Manufacturer Name: Korean Hroparts Elec - Part Type: Connector - Datasheet URL: https://datasheet.lcsc.com/lcsc/2205251630_Korean-Hroparts-Elec-TYPE-C-31-M-12_C165948.pdf - Manufacturer Part Number: TYPE-C-31-M-12 **Pins:** - CC1 [pin A5] - CC2 [pin B5] - DN1 [pin A7] - DN2 [pin B7] - DP1 [pin A6] - DP2 [pin B6] - GND [pin B1A12] - GND [pin A1B12] - SBU1 [pin A8] - SBU2 [pin B8] - SHIELD [pin S3] - SHIELD [pin S1] - SHIELD [pin S4] - SHIELD [pin S2] - VBUS [pin A4B9] - VBUS [pin B4A9] *The full schematic, PCB layout, bill of materials, and interactive design are available at [https://www.flux.ai/vasy_skral/esp32tag-dev-board-reference-design](https://www.flux.ai/vasy_skral/esp32tag-dev-board-reference-design).* --- *Generated from [https://www.flux.ai/vasy_skral/esp32tag-dev-board-reference-design](https://www.flux.ai/vasy_skral/esp32tag-dev-board-reference-design)*