Minimal Pico 2 Humidity Sensor Design

amirkat

amirkat

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.

flux

0:05

Thought for a moment

I’ll keep this minimal: inspect the Pico 2 shield symbol, choose one simple I2C humidity sensor with only required pull-ups/decoupling, wire it to Pico 2 power/GPIO, then run checks and fix any issues.

flux

3:07

Thought for 3 sec

Created 5 tasks.

1/5 Inspect existing Pico 2 shield symbol pins and current schematic state

Thought for 4 sec

Read schematic.

Thought for 3 sec

Found 3 results for I2C humidity and temperature sensor for Raspberry Pi Pico 2 shield, 3.3V operation, minimal support components, available small SMD package, common easy-to-use part such as SHT31-DIS or AHT20. Need pins VDD GND SDA SCL and datasheet availability..

Thought for 4 sec

2/5 Select a minimal humidity sensor and required support parts

Thought for 2 sec

Read SHT31-DIS-B2.5KS datasheet for pin description.

Read SHT31-DIS-B2.5KS datasheet for recommended operating conditions supply .

Read SHT31-DIS-B2.5KS datasheet for typical application circuit pull up resi.

Read SHT31-DIS-B2.5KS datasheet for I2C address ADDR pin.

Thought for 8 sec

Found 2 results for Generic Resistor Generic Capacitor.

Thought for 9 sec

3/5 Add sensor, pull-ups, and decoupling components

Thought for 8 sec

Thought for 8 sec

Thought for 2 sec

4/5 Wire power, ground, and I2C connections to the Pico 2 shield

Thought for 5 sec

Thought for 4 sec

Completed design checks — found 49 issues.

Read schematic.

Thought for a moment

The sensor circuit is wired. Review found only unused Pico 2 shield header pins, so I’m marking those intentionally unused while leaving the SHT31 circuit active on GPIO4/GPIO5.

flux

4:23

Thought for 2 sec

5/5 Run ERC/review and fix any schematic issues

Thought for 7 sec

Thought for 5 sec

Completed design checks — found 18 issues.

Read schematic.

Thought for 10 sec

Found 10 results for 2 pin header 2.54mm connector through hole.

Thought for 6 sec

Thought for 1 sec

Thought for 2 sec

Thought for 2 sec

Completed design checks — found 17 issues.

Thought for 7 sec

Completed design checks — found 17 issues.

Read BOM.

Thought for 10 sec

Thought for 18 sec

Thought for 4 sec

Completed design checks — found 13 issues.

Read BOM.

Thought for 5 sec

5/5 tasks completed.

Thought for a moment

Done — I added the minimal SHT31-DIS humidity/temperature sensor circuit, with 10 kΩ I2C pull-ups, 100 nF local decoupling, Pico GPIO4/GPIO5 I2C wiring, unused pins marked intentionally unused, and manufacturable MPNs for the passives.
Schematic/ERC, manufacturing, and component checks are clean. Full project review still shows PCB airwires because the new parts have not been placed/routed yet; that’s expected before layout.
I also created Minimal Pico 2 Humidity Shield Notes with the wiring, BOM, power budget, and firmware bring-up notes. Ready to proceed to PCB placement when you are.
Proceed to placement
Keep sensor exposed
Minimize board size
Check layout first
Add mounting holes

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Minimal Pico 2 Humidity Shield Notes
Scope
Add the minimum required components for a Raspberry Pi Pico 2 shield with one primary humidity peripheral while keeping the schematic simple.
Selected Peripheral
  • U2: Sensirion SHT31-DIS-B2.5KS humidity/temperature sensor.
  • Reason: simple I2C interface, works from the Pico 2 3.3 V rail, and needs only pull-ups plus one local decoupling capacitor.
Datasheet-Grounded Wiring
From the SHT3x-DIS datasheet:
  • VDD operating range: 2.15 V to 5.5 V, typical 3.3 V.
  • VDD/VSS must be decoupled with 100 nF placed close to the sensor.
  • SDA and SCL are open-drain I/O and require external pull-up resistors; datasheet example uses Rp = 10 kΩ.
  • ADDR must not float; tied low for I2C address 0x44.
  • ALERT must be left floating if unused.
  • nRESET may be left floating if unused.
  • R pin and exposed pad are connected to VSS/GND.

Implemented Connections

NetConnectionsNotes
3V3U1 3V3, U2 VDD, R1 P2, R2 P2, C1 P1Pico 2 module 3.3 V rail powers sensor and pull-ups
GNDU1 GND/AGND pins, U2 VSS/R/EP/ADDR, C1 P2ADDR low selects 0x44
I2C0_SDAU1 GPIO4, U2 SDA, R1 P1Pico I2C0 SDA with 10 kΩ pull-up
I2C0_SCLU1 GPIO5, U2 SCL, R2 P1Pico I2C0 SCL with 10 kΩ pull-up
VBUSU1 VBUSModeled as Pico module USB supply rail

Added BOM Items

DesignatorPartValue / MPNPurpose
U2SHT31-DIS-B2.5KSSensirion SHT31-DIS-B2.5KSHumidity and temperature sensor
R1Generic Resistor10 kΩ, Yageo RC0603FR-0710KLSDA pull-up
R2Generic Resistor10 kΩ, Yageo RC0603FR-0710KLSCL pull-up
C1Generic Capacitor100 nF, Yageo CC0603KRX7R7BB104Sensor VDD decoupling
Power Budget
This shield adds only the SHT31 sensor and two pull-ups to the Pico 2 3.3 V rail. No extra regulator is required because the Pico 2 module already provides 3.3 V.
Approximate added steady-state load:
  • SHT31-DIS: low-current I2C humidity sensor load from 3.3 V.
  • I2C pull-ups: transient current only when SDA/SCL are pulled low; with 10 kΩ at 3.3 V, each line sinks about 0.33 mA when low.
  • Worst case if both I2C lines are low: about 0.66 mA through pull-ups, plus sensor current.
Firmware Bring-Up
Use Pico I2C0 on GPIO4/GPIO5:
  • SDA: GPIO4
  • SCL: GPIO5
  • Sensor address: 0x44
  • Bus pull-ups: present on-board, 10 kΩ to 3V3
Recommended startup sequence:
  1. Initialize I2C0 on GPIO4/GPIO5 at 100 kHz or 400 kHz.
  2. Wait for sensor power-up.
  3. Communicate with address 0x44.
  4. Read humidity/temperature using the Sensirion SHT3x command set or a compatible SHT31 library.
Review Status
  • Schematic ERC for the implemented circuit is clean.
  • Full project review still reports PCB airwires because the new components have not been placed/routed yet; this is expected before entering the layout phase.

    Scope

    Selected Peripheral

    Datasheet-Grounded Wiring

    Implemented Connections

    Added BOM Items

    Power Budget

    Firmware Bring-Up

    Review Status

Documents

    Minimal Pico 2 Humidity Shield Notes

Assets

pico-template.png

pico-template.png

pico-templateThumbnail

Raspberry Pi Pico 2 Shield Template bUFu

Raspberry Pi Pico 2 Shield Template bUFu thumbnail
This is the project template for the Raspberry Pi Pico 2, the latest addition and update to Pi Pico line up.
Raspberry pi pico 2 is equipped with the RP2350, a cutting-edge, high-performance microcontroller designed with enhanced security and versatility in mind. Every element of its design has been upgraded, from the advanced CPU cores to the innovative PIO (Programmable I/O) interfacing subsystem.
The Raspberry Pi Foundation has integrated a robust security architecture centered around Arm TrustZone for Cortex-M, ensuring data protection and integrity. Additionally, new low-power states and expanded package options broaden the range of applications, making the Pico 2 an ideal choice for diverse, power-sensitive projects.
To learn more about what's the key differences between the original Pi Pico and the new Pi Pico 2, read our blog https://www.flux.ai/p/blog/whats-new-in-the-raspberry-pi-pico-2-a-showdown-with-the-original-raspberry-pi-pico
#project-template #template #raspberry #pi #pico2 #newpico

Properties

Properties describe core aspects of the project.

Pricing & Availability

Distributor

Qty 1

Arrow

$2.48–$3.91

Digi-Key

$2.53–$5.63

HQonline

$4.54

LCSC

$0.01

Mouser

$0.40

TME

$6.17

Verical

$2.54–$75.75

Controls