Minimal Pico 2 Sensor Design


Add the minimum required components needed for this Pi Pico 2 to function properly. Keep the design as simple and minimal as possible.
You may include a single humidity sensor as the primary peripheral, along with any essential supporting components such as power regulation, pull-up resistors, decoupling capacitors, or required connectors.
I’ll keep this minimal: inspect the Pico 2 shield pins, select one simple I2C humidity sensor plus only required pull-ups/decoupling/power connections, wire it, then run checks and fix any issues.
The sensor circuit is wired. Review found only unused Pico header pins floating plus VBUS not used on this minimal shield, so I’m marking those intentionally unconnected and re-checking.
VBUS is modeled as a required power input, so I’m adding one simple 2-pin 5V/GND power header rather than adding USB-C circuitry. This keeps the shield minimal and gives the Pico a defined power source in the schematic.
Done — I added a minimal Pico 2 humidity-sensor shield circuit: SHTC3 sensor, 10kΩ I2C pull-ups, 100nF local decoupling, GND/3V3/I2C wiring, and a simple 2-pin 5V/GND VBUS input header.
Validation passed: electrical review now reports no ERROR/WARNING/UNCERTAIN ERC checks. I also saved the design notes and power budget in Minimal Pico 2 Humidity Sensor Shield Design Notes.
Move to layout
Place components
Check BOM
Add firmware notes
Use 4.7k pullups

Minimal Pico 2 Humidity Sensor Shield Design Notes
Scope
Minimal schematic additions for a Raspberry Pi Pico 2 shield:
  • One Sensirion SHTC3 I2C humidity/temperature sensor.
  • Required SHTC3 support components only: SDA/SCL pull-ups and local VDD decoupling.
  • One simple 2-pin 5V/GND input header to satisfy the Pico 2 VBUS power input in the schematic.
Datasheet-grounded SHTC3 requirements
Source: Sensirion SHTC3 datasheet.
  • Supply voltage VDD: 1.62 V to 3.6 V; operated from Pico 2 3V3.
  • Pins: VDD, SCL, SDA, VSS; center/EPAD internally connected to VSS and may be connected to GND.
  • Decoupling: 100 nF capacitor between VDD and VSS, placed close to the sensor.
  • I2C: external pull-up resistors required on SDA and SCL; datasheet example RP = 10 kΩ.
  • I2C clock: supports 0 to 1 MHz Fast Mode Plus.
Power budget

Table


RailLoadTypicalPeak
3V3SHTC3 average normal mode, 1 measurement/s4.9 uA-
3V3SHTC3 measurement normal mode430 uA900 uA
Added shield sensor load on Pico 3V3: 900 uA peak. The 3V3 and VBUS net metadata use 0.001 A max current for this added load. Pico 2 board current itself depends on firmware and is supplied through the VBUS header or onboard Pico USB power path.
Connections
  • U2 SHTC3 VDD -> 3V3.
  • U2 SHTC3 VSS and EPAD -> GND.
  • C1 100 nF -> between 3V3 and GND near U2.
  • U2 SDA -> U1 GPIO4 / I2C_SDA, with R1 10 kΩ pull-up to 3V3.
  • U2 SCL -> U1 GPIO5 / I2C_SCL, with R2 10 kΩ pull-up to 3V3.
  • J1 Pin_1 -> VBUS, J1 Pin_2 -> GND.
Validation
Electrical review after wiring and no-connect marking reports no ERROR, WARNING, or UNCERTAIN ERC checks matching the validation filter.
  • Scope

  • Datasheet-grounded SHTC3 requirements

  • Power budget

  • Connections

  • Validation