Capacitive soil moisture sensor with Raspberry Pi Pico 2

Wiring for the Capacitive soil moisture sensor v1.2 on the Raspberry Pi Pico 2 (RP2350, 3.3 V logic), chosen with the same pin rules BoardPilot uses: default buses first, and no pins that are used for flash, USB, the debugger or booting.

Wiring

Check before you power it on

• Supply: 3.3 V from the 3V3(OUT) pin.

Test code (Arduino)

void setup() {
  Serial.begin(115200);
  analogReadResolution(12);
}

void loop() {
  long mv = (long)analogRead(26) * 3300L / 4095;  // AOUT on GP26
  Serial.println(mv);
  delay(200);
}

Arduino board: rp2040:rp2040:rpipico2. If the board is not found, hold the BOOTSEL button while plugging in the USB cable.

Questions

Which Raspberry Pi Pico 2 pins do I use for the Capacitive soil moisture sensor?

GND → GND, VCC → 3V3(OUT), AOUT → GP26.

Does the Capacitive soil moisture sensor work with the Raspberry Pi Pico 2 at 3.3 V?

Yes: the Capacitive soil moisture sensor runs at 3.3-5 V and the Raspberry Pi Pico 2 uses 3.3 V signals, so no level shifting is needed.

Full Raspberry Pi Pico 2 pinout · Capacitive soil moisture sensor v1.2: all pins and data

The Capacitive soil moisture sensor on other boards

ESP32 DevKit Arduino Mega 2560 R3 Arduino Nano Arduino Uno R3 WeAct Black Pill STM32F411CE ESP32-C3-DevKitM-1 ESP32-S3-DevKitC-1 Nordic nRF52840 DK NUCLEO-F401RE Raspberry Pi Pico W Raspberry Pi Pico Teensy 4.1

Other parts on the Raspberry Pi Pico 2

BME280 BMP280 DHT22 DHT11 HC-SR04 SSD1306 OLED MPU6050 DS18B20 WS2812B LED strip SG90 servo Relay module HC-SR501 PIR LCD 1602 I2C INA219 VL53L0X BH1750 MAX30102 RC522 RFID NEO-6M GPS ADS1115 TM1637 28BYJ-48 stepper L298N Potentiometer Push button LED Joystick module SD card module AHT20