DS18B20 with Raspberry Pi Pico

Wiring for the DS18B20 waterproof temperature probe on the Raspberry Pi Pico (RP2040, 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

DS18B20 pin	Role	Raspberry Pi Pico pin	Notes
VDD	Power	3V3(OUT)	Red wire
DQ	One-wire data	GP15	Yellow (sometimes white) wire. Needs a 4.7 kΩ pull-up to 3.3 V
GND	Ground	GND	Black wire

Check before you power it on

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

Test code (Arduino)

// Library: OneWire, DallasTemperature
#include <OneWire.h>
#include <DallasTemperature.h>

OneWire bus(15);  // needs a 4.7 kΩ pull-up from DQ to VDD
DallasTemperature sensors(&bus);

void setup() {
  Serial.begin(115200);
  sensors.begin();
  Serial.print("Sensors found: ");
  Serial.println(sensors.getDeviceCount());
}

void loop() {
  sensors.requestTemperatures();
  Serial.println(sensors.getTempCByIndex(0));
  delay(1000);
}

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

Questions

Which Raspberry Pi Pico pins do I use for the DS18B20?

VDD → 3V3(OUT), DQ → GP15, GND → GND.

Does the DS18B20 work with the Raspberry Pi Pico at 3.3 V?

Yes: the DS18B20 runs at 3.3-5 V and the Raspberry Pi Pico uses 3.3 V signals, so no level shifting is needed.

BoardPilot checks this wiring in 3D as you build it, and finds crossed or missing wires on the real board.

Download BoardPilot

Full Raspberry Pi Pico pinout · DS18B20 waterproof temperature probe: all pins and data

The DS18B20 on other boards

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