Temperature and Humidity Sensor Node Design

Make me a temperature and humidity sensor node with Wifi and Bluetooth, powered by USB-C (5V) for consumer use.

It should be a low-power environmental node with a digital T/RH sensor, ultra-low-power MCU with Wi-Fi + Bluetooth (dual-radio) — 2.4 GHz 802.11 b/g/n plus BLE 5.x powered by USB-C (5 V) — USB-C receptacle 5 V default; include reverse/OVP/UVLO/OCP protection and plan for 0.5–3 A sources.

6 days

flux

1:11

Thinking deeply about your request.

Creating a project plan.

Working on your request.

Analyzing the PCB layout.

Analyzing the schematic.

Planning requirements capture.

Working on your request.

Summarizing proposed plan.

Summarizing components and actions.

You want a low-power USB-C temperature/humidity sensor node with Wi-Fi + Bluetooth and protected 5 V power input.

I’ve prepared a Plan to:

define the USB-C input and protection chain
add power regulation
integrate the wireless MCU and digital T/RH sensor
connect and review the full schematic

It’s ready to execute. Click Start on the plan bar to build it.

Plan

#Goal

Design a low-power consumer temperature and humidity sensor node for the 'Fragile Orange Tricorder' project. This node will integrate a digital temperature/humidity sensor and an ultra-low-power MCU with dual-radio 2.4 GHz Wi-Fi (802.11 b/g/n) and Bluetooth LE 5.x, powered by a 5 V USB-C input. The design will include a robust front-end protection circuit covering reverse polarity, over-voltage, under-voltage, and over-current conditions, compatible with USB-C sources ranging from 0.5 A to 3 A.

#Implementation plan

USB-C Power Input and Front-End Protection
1. Add a USB-C connector to the schematic.
2. Design a front-end protection circuit incorporating:
  1. Reverse polarity protection (e.g. using a Schottky diode or MOSFET based circuit).
  2. Over-voltage and under-voltage protection using TVS diodes and voltage supervisors.
  3. Over-current protection with a resettable fuse or current limiter suitable for 0.5 A to 3 A sources.
3. Confirm that the protection circuit does not impact the low-power operation during standby.
Power Regulation Subsystem
1. Add a low-dropout regulator (or buck converter) to step down from the protected 5 V input to the 3.3 V (or required voltage) for the MCU and sensor.
2. Verify proper filtering and decoupling with capacitors to ensure stable power for low-power operation.
MCU and Wireless Connectivity
1. Select and add an ultra-low-power MCU with dual-radio capabilities (Wi-Fi 802.11 b/g/n and Bluetooth LE 5.x), such as the ESP32-WROOM series.
2. Place the MCU in the schematic and connect it to the power regulator, ensuring proper decoupling and crystal clock if needed.
Digital Temperature/Humidity Sensor
1. Select and add a digital temperature/humidity sensor (for example, Sensirion SHT3x or a similar low-power sensor).
2. Connect the sensor to the MCU via appropriate digital interface (typically I²C), including pull-up resistors if required.
System Integration and Verification
1. Connect all sub-systems together, ensuring proper net connections between the power rail, MCU, sensor, and protection circuits.
2. Update the project description to include the defined system architecture and component functionalities.
3. Review the schematic for component completeness and functional integrity.

#Success criteria

The schematic includes a USB-C connector, complete front-end protection circuitry, and proper power regulation from 5 V to required levels.
The ultra-low-power MCU with dual-radio capabilities and digital sensor are correctly integrated with proper digital communications.
The design meets the consumer low-power requirements and operates safely with USB-C sources between 0.5 A and 3 A.

Add ESD too

Use ESP32-C6

Set 3.3V rail

Prefer compact BOM

6 days

Reviews

Ground
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A generic fixed capacitor ideal for rapid circuit topology development. You can choose between polarized and non-polarized types, its symbol and the footprint will automatically adapt based on your selection. Supported options include standard SMD sizes for ceramic capacitors (e.g., 0402, 0603, 0805), SMD sizes for aluminum electrolytic capacitors, and through-hole footprints for polarized capacitors. Save precious design time by seamlessly add more information to this part (value, footprint, etc.) as it becomes available. Standard capacitor values: 1.0pF, 10pF, 100pF, 1000pF, 0.01uF, 0.1uF, 1.0uF, 10uF, 100uF, 1000uF, 10000uF 1.1pF, 11pF, 110pF, 1100pF 1.2pF, 12pF, 120pF, 1200pF 1.3pF, 13pF, 130pF, 1300pF 1.5pF, 15pF, 150pF, 1500pF, 0.015uF, 0.15uF, 1.5uF, 15uF, 150uF, 1500uF 1.6pF, 16pF, 160pF, 1600pF 1.8pF, 18pF, 180pF, 1800pF 2.0pF, 20pF, 200pF, 2000pF 2.2pF, 22pF, 220pF, 2200pF, 0.022uF, 0.22uF, 2.2uF, 22uF, 220uF, 2200uF 2.4pF, 24pF, 240pF, 2400pF 2.7pF, 27pF, 270pF, 2700pF 3.0pF, 30pF, 300pF, 3000pF 3.3pF, 33pF, 330pF, 3300pF, 0.033uF, 0.33uF, 3.3uF, 33uF, 330uF, 3300uF 3.6pF, 36pF, 360pF, 3600pF 3.9pF, 39pF, 390pF, 3900pF 4.3pF, 43pF, 430pF, 4300pF 4.7pF, 47pF, 470pF, 4700pF, 0.047uF, 0.47uF, 4.7uF, 47uF, 470uF, 4700uF 5.1pF, 51pF, 510pF, 5100pF 5.6pF, 56pF, 560pF, 5600pF 6.2pF, 62pF, 620pF, 6200pF 6.8pF, 68pF, 680pF, 6800pF, 0.068uF, 0.68uF, 6.8uF, 68uF, 680uF, 6800uF 7.5pF, 75pF, 750pF, 7500pF 8.2pF, 82pF, 820pF, 8200pF 9.1pF, 91pF, 910pF, 9100pF #generics #CommonPartsLibrary
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Project Name

Fragile Orange Tricorder

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siriusillumination / Fragile Orange Tricorder

Schematic