MAX30102 with Raspberry Pi Pico 2

Wiring for the MAX30102 heart rate + SpO2 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

MAX30102 pin	Role	Raspberry Pi Pico 2 pin	Notes
VIN	Power	3V3(OUT)
SDA	I2C data (SDA)	GP4
SCL	I2C clock (SCL)	GP5
INT	Interrupt	GP15
IRD	Not wired to the board	not connected	IR LED output. Leave unconnected
RD	Not wired to the board	not connected	Red LED output. Leave unconnected
GND	Ground	GND

Check before you power it on

Supply: 3.3 V from the 3V3(OUT) pin.
I2C uses the board’s default pins GP4 (SDA) and GP5 (SCL). Most modules include pull-up resistors; if the part is not found, check them and swap-test SDA/SCL.
To make sure it is the real chip, read register 0xFF: a genuine part answers 0x15.

Test code (Arduino)

#include <Wire.h>

void setup() {
  Serial.begin(115200);
  Wire.begin();  // SDA = GP4, SCL = GP5 (the board's default I2C pins)
  Wire.beginTransmission(0x57);
  bool found = Wire.endTransmission() == 0;
  Serial.println(found ? "MAX30102 heart rate + SpO2 found at 0x57" : "Not found: check power, GND and SDA/SCL");
}

void loop() {}

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 MAX30102?

VIN → 3V3(OUT), SDA → GP4, SCL → GP5, INT → GP15, GND → GND.

Does the MAX30102 work with the Raspberry Pi Pico 2 at 3.3 V?

Yes: the MAX30102 runs at 3.3-5 V and the Raspberry Pi Pico 2 uses 3.3 V signals, so no level shifting is needed.

What is the I2C address of the MAX30102?

0x57. An I2C scan (BoardPilot does it for you) shows which one your module uses.

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 2 pinout · MAX30102 heart rate + SpO2: all pins and data

The MAX30102 on other boards

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