# Unique Brown Tricorder ## Description Cow health-monitoring wearable PCB for a cow-mounted device. Rear strap electronics target 20-25 g and front sensing assembly target about 15 g. Uses an ESP32-based sensor controller, 200 mAh LiPo battery, battery charging circuitry, and interfaces for ammonia, methane, IR temperature, and saliva sensing. Design must tolerate moisture, mucus, debris, vibration, fur contact, and tongue/lick exposure while remaining compact and lightweight for wearable use. ## Project Details - **Owner:** vigarg - **Created:** 3/26/2026 - **Last Updated:** 3/27/2026 - **Visibility:** Public - **Operating Temperature:** Cow-wearable outdoor/field environment - **Power Requirements:** 200mAh LiPo battery, USB charging, regulated 3.3V system rail - **Domain:** Wearable livestock health monitoring - **Implementation Details:** Placement-ready baseline for cow health-monitoring wearable. Mechanical constraints locked to 45mm x 25mm rectangle with 3mm corner radius, 0.5mm board inset margin, and 0.2mm keep out. Placement priority: USB-C and battery connector at opposite edges, ESP32 module near board edge with antenna keepout preserved, power/charging cluster adjacent to connectors, saliva/debug headers at accessible edges, IR sensor near optical edge, gas sensor placeholders isolated from ESP32 antenna and analog inputs. Routing priority: power and ground first, then I2C, then UART/debug, then analog sensor nets. Reserved MCU and placeholder sensor pins are do-not-route and should remain explicit no-connects. - **Reliability Target (MTBF):** Robust against vibration, moisture, and debris exposure - **Manufacturing Quantity Target:** Prototype phase-1 wearable validation - **Connectivity:** WiFi/BLE via ESP32 ## Key Components ### J1 — [Type-C-2.0-6Pin](https://www.flux.ai/jharwinbarrozo/type-c-20-6pin~wh.md) - Role Details: Power-only USB-C connector exposing VBUS, GND, CC1, and CC2 - Manufacturer Part Number: Type-C-2.0-6Pin - Manufacturer Name: CIKI - Package: USB-C SMT - Role: USB Power Input - Datasheet URL: https://datasheet.lcsc.com/lcsc/2204071830_CIKI-Type-C-2-0-6Pin_C2987385.pdf - Part Type: Connector **Pins:** - CC1 - CC2 - GND - GND__1 - SHIELD - SHIELD__1 - SHIELD__2 - SHIELD__3 - V-BUS - V-BUS__1 ### J2 — [S2B-PH-SM4-TB(LF)(SN)](https://www.flux.ai/adrian95/s2b-ph-sm4-tblfsn~b96.md) - Role: Battery Connector - Package: JST-PH 2.0mm SMT - Manufacturer Name: JST Sales America Inc. - Datasheet URL: https://www.jst-mfg.com/product/pdf/eng/ePH.pdf - Part Type: Connector - Manufacturer Part Number: S2B-PH-SM4-TB(LF)(SN) - License: https://creativecommons.org/licenses/by/4.0/ - Role Details: Single-cell LiPo battery connector for 200mAh pack **Pins:** - P1 [pin 1] - P2 [pin 2] ### J3 — [653104131822](https://www.flux.ai/adrian95/653104131822~sx.md) - Role Details: External connector for saliva sensing electrodes and analog front-end signals - Package or Case Code: 653104131822 - Role: Saliva Sensor Interface - Part Type: Connector - Manufacturer Name: Wurth Elektronik - License: https://creativecommons.org/licenses/by/4.0/ - Datasheet URL: https://datasheet.datasheetarchive.com/originals/distributors/Datasheets_SAMA/448ee1d780e65e7cf16e36a5052d2491.pdf - Implementation Details: Pin 1 = SALIVA_PH analog input, Pin 2 = SALIVA_COND analog input, Pin 3 = GND reference, Pin 4 = 3V3 placeholder bias/reference. This connector is intentionally reserved for future saliva front-end circuitry, should be kept at board edge during placement, and its interface intent is frozen for this baseline. - Manufacturer Part Number: 653104131822 - Package: 1.25mm SMT Header **Pins:** - 1 [pin 1] - 2 [pin 2] - 3 [pin 3] - 4 [pin 4] ### J4 — [653104131822](https://www.flux.ai/adrian95/653104131822~sx.md) - Part Type: Connector - License: https://creativecommons.org/licenses/by/4.0/ - Manufacturer Name: Wurth Elektronik - Datasheet URL: https://datasheet.datasheetarchive.com/originals/distributors/Datasheets_SAMA/448ee1d780e65e7cf16e36a5052d2491.pdf - Package: 1.25mm SMT Header - Role Details: 4-pin debug header for 3.3V, GND, UART TX, UART RX - Package or Case Code: 653104131822 - Role: Debug Header - Implementation Details: 4-pin support/debug header. Pin 1 = GND, Pin 2 = UART_TX_HDR from ESP32 TX through 100 ohm series resistor, Pin 3 = UART_RX_HDR to ESP32 RX through 100 ohm series resistor, Pin 4 = 3V3 reference. Keep accessible but de-prioritized versus wearable sensor connectors during placement. Header intent is frozen for this baseline. - Manufacturer Part Number: 653104131822 **Pins:** - 1 [pin 1] - 2 [pin 2] - 3 [pin 3] - 4 [pin 4] ### U1 — [ESP32-WROOM-32](https://www.flux.ai/vasyl/esp32-wroom-32~siz.md) - Role Details: ESP32 module for wearable sensing, I2C sensors, analog interfaces, and wireless connectivity - Manufacturer Name: Espressif Systems - Manufacturer Part Number: ESP32-WROOM-32 - Implementation Details: Reserved floating pins have been annotated as no-connect for ERC compliance. - Role: Main Controller - Part Type: RF module - Package: Module - Datasheet URL: https://www.espressif.com/sites/default/files/documentation/esp32-wroom-32_datasheet_en.pdf **Pins:** - EN [pin 3] - GND [pin 38] - GND [pin 39] - GND [pin 1] - GND [pin 15] - 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 32] - RXD0/IO3 [pin 34] - SCK/CLK [pin 20] - SCS/CMD [pin 19] - SDI/SD1 [pin 22] - SDO/SD0 [pin 21] - SENSOR_VN [pin 5] - SENSOR_VP [pin 4] - SHD/SD2 [pin 17] - SWP/SD3 [pin 18] - TXD0/IO1 [pin 35] - VDD [pin 2] ### U2 — [MCP73831T-2ACI/OT](https://www.flux.ai/adrian95/mcp73831t-2aciot~922.md) - Package: SOT-23-5 - Part Type: Integrated Circuit - Implementation Details: USB-powered single-cell LiPo charger for 200mAh battery. VIN from VBUS_5V, VBAT to system battery rail / 3V3 source node in this baseline, PROG set by R6 for about 100mA fast charge, STAT available for optional indicator use. Charger block intent is frozen for this baseline. - Role: Battery Charger - Manufacturer Part Number: MCP73831T-2ACI/OT - Role Details: USB-powered single-cell LiPo charger for 200mAh battery - Manufacturer Name: Microchip Technology - Datasheet URL: https://ww1.microchip.com/downloads/en/DeviceDoc/MCP73831-Family-Data-Sheet-DS20001984H.pdf - License: https://creativecommons.org/licenses/by/4.0/ **Pins:** - PROG [pin 5] - STAT [pin 1] - VBAT [pin 3] - VIN [pin 4] - VSS [pin 2] ### U3 — [ME6211C33M5G-N](https://www.flux.ai/jecstronic/me6211c33m5g-n~a2.md) - Part Type: LDO - Manufacturer Part Number: ME6211C33M5G-N - Role Details: Low-dropout 3.3V regulator from LiPo battery to system rail - Implementation Details: ME6211 LDO enabled continuously by tying CE to 3V3 in this baseline. Place close to battery connector and charger output with short paths to C2 and C3. Regulator block intent is frozen and should not be changed during placement/routing. - Role: 3.3V Regulator - Datasheet URL: https://datasheet.lcsc.com/lcsc/1811131510_MICRONE-Nanjing-Micro-One-Elec-ME6211C33M5G-N_C82942.pdf - Manufacturer Name: MICRONE(Nanjing Micro One Elec) - Package: SOT-23-5 **Pins:** - CE - NC - VIN - VOUT - VSS ### U4 — [MLX90614ESF-ACC-000-SP](https://www.flux.ai/jecstronic/mlx90614esf-acc-000-sp~si.md) - Role Details: I2C non-contact temperature sensor placeholder for forehead measurement - Package: TO-39 - Datasheet URL: https://media.melexis.com/-/media/files/documents/datasheets/MLX90614-datasheet-melexis.pdf - Role: IR Temperature Sensor - Manufacturer Part Number: MLX90614ESF-ACC-000-SP - License: https://creativecommons.org/licenses/by/4.0/ - Manufacturer Name: Melexis Technologies NV - Implementation Details: IR temperature sensor placeholder on I2C. SCL_Vz and PWM_SDA share the I2C bus, VDD on 3V3, VSS on GND. Keep near edge/window region during placement for later optical access. Sensor intent is frozen for baseline placement. - Part Type: Sensor **Pins:** - PWM_SDA [pin 2] - SCL_Vz [pin 1] - VDD [pin 3] - VSS [pin 4] ### U5 — [MQ-137](https://www.flux.ai/vasy_skral/mq-137~h38.md) - Manufacturer Name: SparkFun Electronics - Part Type: Integrated Circuit - Package: Gas Sensor - Role: Ammonia Sensor Placeholder - Datasheet URL: https://cdn.sparkfun.com/assets/7/0/2/f/8/MQ137__Ver1.4__-_Manual.pdf - Implementation Details: MQ-137 used as ammonia-sensing placeholder. A1/A2 tied together to NH3_SENSE analog net, B2 and VH+ tied to 3V3 for placeholder biasing, B1 and VH- tied to GND. Heater drive and analog conditioning are deferred to later revision; avoid extra routing beyond defined placeholder nets. Sensor intent is frozen for baseline placement. - Role Details: Prototype ammonia sensing placeholder with analog output front-end requirement - Manufacturer Part Number: MQ-137 - License: https://creativecommons.org/licenses/by/4.0/ **Pins:** - A1 [pin 6] - A2 [pin 4] - B1 [pin 1] - B2 [pin 3] - VH- [pin 5] - VH+ [pin 2] ### U6 — [CCS811](https://www.flux.ai/kicad-part-library/ccs811~06r.md) - Manufacturer Part Number: CCS811 - Manufacturer Name: Texas Instruments Inc. - Role Details: I2C gas sensor placeholder representing methane-related air quality sensing - Package or Case Code: AMS_LGA-10-1EP_2.7x4mm_P0.6mm - Role: Methane Sensor Placeholder - Implementation Details: Placeholder floating pins have been annotated as no-connect for ERC compliance. - Package: LGA - Datasheet URL: https://www.sciosense.com/wp-content/uploads/documents/SC-001232-DS-3-CCS811B-Datasheet-Revision-2.pdf **Pins:** - ~{INT} [pin 3] - ~{RESET} [pin 2] - ~{WAKE} [pin 7] - ADDR [pin 1] - AUX [pin 8] - GND [pin 11] - PWM [pin 4] - SCL [pin 10] - SDA [pin 9] - Sense [pin 5] - VDD [pin 6] *The full schematic, PCB layout, bill of materials, and interactive design are available at [https://www.flux.ai/vigarg/unique-brown-tricorder~b0](https://www.flux.ai/vigarg/unique-brown-tricorder~b0).* --- *Generated from [https://www.flux.ai/vigarg/unique-brown-tricorder~b0](https://www.flux.ai/vigarg/unique-brown-tricorder~b0)*