#Goal

- Design a consumer temperature and humidity sensor node that operates as a low-power environmental monitoring device. The device will use a digital temperature/RH sensor and an ultra-low-power MCU with dual 2.4 GHz 802.11 b/g/n Wi-Fi and BLE 5.x radios, powered by a USB-C 5V default sink. The design must include reverse polarity protection, over-voltage protection, under-voltage lockout, and over-current/current limiting protection to handle USB-C sources from 0.5 A to 3 A.

#Implementation plan

1. Define the Requirements and System Architecture

1. Update the project description with the environmental sensor node goal and its consumer application target.

2. Document the system architecture highlighting the low-power sensor node, sensor interface, MCU dual radio capabilities, and USB-C power management with protection circuitry.

2. Select and Add Major Components

1. Select and add an ultra-low-power MCU with integrated Wi-Fi (2.4 GHz 802.11 b/g/n) and BLE 5.x radio from the Flux parts library.

2. Select and add a digital temperature and RH sensor from the library.

3. Select and add a USB-C receptacle component and design a power input stage.

3. Design the Power and Protection Subsystem

1. Implement and add reverse polarity protection elements using appropriate diodes or MOSFET circuits.

2. Incorporate over-voltage protection (OVP) and under-voltage lockout (UVLO) circuits; add TVS diodes and voltage monitoring components from the library.

3. Integrate over-current/current limiting protection to cope with the 0.5 A to 3 A USB-C standards.

4. Design the power regulation stage to safely derive necessary supply rails for the MCU and sensor.

4. Build the Schematic

1. Interconnect the MCU, sensor, power protection circuitry, and USB-C connector.

2. Add decoupling capacitors and generic passives with proper resistance and capacitance values where needed.

3. Verify the interconnections for RF-critical paths (Wi-Fi/BLE) and sensor exposure to environmental conditions.

5. Prepare Supporting Documentation and PCB Layout Guidance

1. Update the project metadata and add project files to document design requirements and firmware provisioning.

2. Outline the initial PCB layout, including RF antenna placement, USB-C connector location, and protected power path.

3. Specify design rules for proper passive wiring and signal integrity, especially in RF regions.

#Success criteria

- The schematic includes all required components: ultra-low-power dual radio MCU, digital temperature/RH sensor, USB-C receptacle with protection circuits (reverse polarity, OVP, UVLO, OCP).

- The power management circuit meets the conditions for USB-C inputs ranging from 0.5 A to 3 A.

- Updated project files reflect the architectural intent and support firmware development for the sensor node.

- Initial PCB layout considerations, especially for RF antenna and USB-C, support manufacturability and proper function.

Renamed to: "USB-C WiFi BLE T-RH Sensor Node"

Updated to: "Consumer USB-C powered low-power temperature and humidity sensor node with Wi-Fi/BLE connectivity, I2C digital T/RH sensing, and protected 5 V input power management."

Set Domain to "Consumer Electronics"

Set Operating Voltage to "5"

Set Connectivity to "WiFi"

Set Power Requirements to "USB"

Set Implementation Details to "USB-C 5 V default sink; 3.3 V rail; Wi-Fi/BLE MCU module; I2C digital T/RH sensor; reverse/OVP/UVLO/OCP input protection plan..."

Connected U1:DOUT, U2:GPIO0 to ^AMC1306_DOUT_PIO

Connected U1:CLKIN, U2:GPIO1 to ^AMC1306_CLKIN_PIO

Added 1x ESP32-C3-MINI-1-N4 as U1 (Pins: GND::51, NC::35, GND::36, GND::49_9, IO1, GND::1, NC::4, GND::49_6, NC::10, RXD0, EN, GND::46, GND::49_3, TXD0, NC::32 ... and 46 more)

Added 1x SHTC3-TR-2.5KS as U2 (Pins: SCL, SDA, VSS, VDD, EPAD)

Added 1x USB-C 2.0 Receptacle as J1 (Pins: SBU2, GND::1, VBUS::3, GND::16, VBUS::14, D-::7, GND::15, GND::2, D-::9, CC1, VBUS::4, D+::10, VBUS::13, D+::8, SBU1 ... and 1 more)

Added 1x TPS25940LRVCR as U3 (Pins: DVDT, OUT_5, IN_4, DEVSLP, OUT_3, EP, IN_2, PGTH, PGOOD, IN_3, ~FLT, OUT_2, IN_1, OUT_1, IMON ... and 6 more)

Added 1x AP2112K-3.3TRG1 as U4 (Pins: VIN, EN, GND, NC, VOUT)

Added 6x Generic Resistor as R1, R2, R3, R4, R5, R6 (Pins: P2, P1)

Added 7x Generic Capacitor as C1, C2, C3, C4, C5, C6, C7 (Pins: P1, P2)

Removed U1

Removed U2

Removed Q1