This repository contains examples for the Raspberry Pi Pico 2 (RP2350) board, written in Rust using the Embassy async framework.
Project generated
cargo generate --git https://github.com/ImplFerris/pico2-template.git --name rust-rpico2-embassy-examples
Hardware
Board: Raspberry Pi Pico 2
- MCU: RP2350 (Dual-core Arm Cortex-M33 and RISC-V cores)
- On-board peripherals:
- LED on GPIO25
Pinout
Common Pin Assignments
- I2C pins:
- I2C0 SDA: GPIO4
- I2C0 SCL: GPIO5
- I2C1 SDA: GPIO2
- I2C1 SCL: GPIO3
- UART pins:
- UART0 TX: GPIO0, UART0 RX: GPIO1
- UART1 TX: GPIO8, UART1 RX: GPIO9
Examples
I2C Examples
hs3003_i2c
Reads temperature and humidity from an HS3003 sensor using the Embassy async framework.
cargo run --example hs3003_i2c
Wiring (Arduino Modulino Thermo):
Modulino -> RPi Pico 2
---------- --------------
GND (black) -> GND
VCC (red) -> 3.3V
SCL (yellow)-> GPIO5 (Pin 7) (I2C0 SCL)
SDA (blue) -> GPIO4 (Pin 6) (I2C0 SDA)
About HS3003:
The Renesas HS3003 is a high-performance temperature and humidity sensor:
- Temperature range: -40°C to +125°C (±0.2°C accuracy)
- Humidity range: 0% to 100% RH (±1.5% accuracy)
- 14-bit resolution for both measurements
- Ultra-low power consumption
adxl345_i2c
Reads accelerometer data from an ADXL345 sensor over I2C0 using Embassy.
cargo run --example adxl345_i2c
Wiring:
ADXL345 -> RPi Pico 2
---------- --------------
GND (black) -> GND
VCC (red) -> 3.3V
SCL (yellow)-> GPIO5 (Pin 7) (I2C0 SCL)
SDA (blue) -> GPIO4 (Pin 6) (I2C0 SDA)
About ADXL345:
The ADXL345 is a small, thin, low power, 3-axis accelerometer with high resolution (13-bit) measurement at up to ±16 g. Digital output data is formatted as 16-bit twos complement and is accessible through either an SPI (3- or 4-wire) or I2C digital interface.
SPI Display Examples
zermatt
Displays a 320x240 image of Zermatt on the Adafruit 2.2" TFT LCD display in landscape mode.
cargo run --example zermatt
Wiring (Eye-SPI Breakout):
Raspberry Pi Pico 2 Eye-SPI Breakout
+-----------------------+ +---------------------------+
| | | |
| 3V3 (Pin 36) --------+------+-> VIN (Red Wire) |
| GND (Pin 38) --------+------+-> GND (Black Wire) |
| GPIO18 (Pin 24) -----+------+-> SCK (Blue Wire) |
| GPIO19 (Pin 25) -----+------+-> MOSI (Green Wire) |
| GPIO16 (Pin 21) -----+------+-> MISO (Yellow Wire) |
| GPIO20 (Pin 26) -----+------+-> DC (White Wire) |
| GPIO21 (Pin 27) -----+------+-> RST (Orange Wire) |
| GPIO17 (Pin 22) -----+------+-> TCS (Blue Wire) |
| | | |
+-----------------------+ +---------------------------+
zermatt_snow
Displays a 320x240 image of Zermatt on the Adafruit 2.2" TFT LCD display with animated falling snow, utilizing a physics engine and the Embassy async framework to draw to an off-screen lcd-async framebuffer and dispatch via DMA without blocking the CPU.
cargo run --example zermatt_snow
Wiring is identical to the zermatt example.
1-Wire Examples
ds18b20
Reads temperature from a DS18B20 waterproof temperature sensor probe over a 1-Wire bus using Embassy. It utilizes a custom, cycle-accurate PreciseDelay implementation to achieve jitter-free sub-microsecond timing required by the 1-Wire protocol on the RP2350's Cortex-M33 core.
cargo run --example ds18b20
Wiring Schematic:
Raspberry Pi Pico 2
+-----------------------+
| |
| [ ] 1 40 [ ] USB |
| [ ] 2 39 [ ] |
| [ ] 3 38 [G]ND --+-------+ (black)
| [ ] 4 37 [ ] | |
| [ ] 5 36 [3]V3 --+---+ |
| ... ... | | |
| [ ] 20 21 [ ] ----+---+---|---+ (white, GPIO16)
+-----------------------+ | | |
| | |
| | |
+-----------------------------+ | | |
| DS18B20 Sensor / Probe | | | |
| (Bottom/Flat Side) | | | |
| | | | |
| [GND] [DAT] [VCC] | | | |
+-------|-------|-------|-----+ | | |
| | | | | |
| +-------+--[5K1]----+ | (Pull-Up Resistor
| | | Resistor | between DAT & VCC)
| | +---------------+ (red)
+-------|-----------------------+ (black)
|
+--------------------------- (white)
Breadboard Layout:
About DS18B20:
The DS18B20 is a 1-Wire digital thermometer that provides 9-bit to 12-bit Celsius temperature measurements. It communicates over a 1-Wire bus, requiring only one data line (and ground) to interface with the microcontroller. It has a temperature range of -55°C to +125°C with ±0.5°C accuracy from -10°C to +85°C.
dht11
Reads temperature and humidity from a DHT11 sensor using the Embassy async framework. It utilizes the async API of the dht-sensor crate combined with our cycle-accurate PreciseDelay implementation.
cargo run --example dht11 --release
Note: Due to timing sensitivity of the DHT11 protocol during the bit-read phase, you must run this example in release mode.
Wiring Schematic:
Raspberry Pi Pico 2 DHT11 Module
+---------------------+ +---------------------+
| | | |
| GND (Pin 38) -------+----->| GND |
| 3V3 (Pin 36) -------+----->| VCC |
| GPIO16 (Pin 21) ----+----->| DAT (Data) |
| | | |
+---------------------+ +---------------------+
Important
Pull-up Resistor:
- If using a DHT11 module board: It likely already has a built-in pull-up resistor. No extra component is needed.
- If using a bare 4-pin DHT11 sensor: You must add an external 4.7kΩ to 10kΩ pull-up resistor between the DAT (Data) and VCC lines.
About DHT11:
The DHT11 is a basic, ultra low-cost digital temperature and humidity sensor. It uses a capacitive humidity sensor and a thermistor to measure the surrounding air, and spits out a digital signal on the data pin (no analog input pins needed). It has a temperature range of 0°C to 50°C (±2°C accuracy) and humidity range of 20% to 90% RH (±5% accuracy).
Wi-Fi & Matter Examples
matter_wifi_light
Implements a Matter-compatible Wi-Fi light bulb using the rs-matter stack. It uses BLE for commissioning and Wi-Fi for network connectivity, allowing you to add the Pico 2 W directly into Apple Home, Google Home, or Home Assistant! When toggled from your smart home app, it turns an external LED on and off.
cargo run --example matter_wifi_light --release
Provisioning in Home Assistant:
-
Run the example on your Pico 2 W. It will begin advertising over Bluetooth.
-
Open the Home Assistant companion app on your smartphone.
-
Go to Settings -> Devices & Services -> Add Integration -> Add Matter device.
-
When prompted for a setup code, enter the default
3497-0112-332(or scan the QR code link printed in the terminal logs). -
Home Assistant will connect to the Pico 2 W over BLE, ask for your Wi-Fi credentials, and securely transmit them to the device.
-
The Pico 2 W will connect to your Wi-Fi network and immediately appear as a standard light bulb. You can use the Home Assistant interface to toggle the light on and off!
-
The external LED wired to your Pico 2 W will instantly mirror the state!
Wiring Schematic:
Raspberry Pi Pico 2 W External Components
+------------------------+
| |
| GP15 (Pin 20) |---------[ 220-330 Ohm Resistor ]-----+
| | |
| GND (Pin 18) |------------------[ LED - ] <---+ |
| | | |
+------------------------+ (Cathode / | |
Short Leg) | |
| |
[ LED + ] -+-----+
(Anode /
Long Leg)
Basic GPIO Examples
blinky
Blinks an external LED connected to GPIO15. This is useful for boards like the Raspberry Pi Pico 2 W, where the onboard LED is connected to the wireless chip rather than a standard microcontroller GPIO.
cargo run --example blinky
Wiring: Same wiring as the matter_wifi_light example.