Adafruit STHS34PF80 IR Presence / Motion Sensor

A deluxe PIR sensor

by Liz Clark

published October 22, 2025, last edited October 22, 2025

posted in Adafruit Products Sensors/ Proximity Arduino Compatibles CircuitPython STEMMA

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Beginner

Product guide

Overview

We stock many low cost "Passive IR" Presence / Motion sensors, and they're very popular for detecting motion from humanoids and pets 5 to 20 feet away. (They possibly work on zombies, not guaranteed, depends on how warm they are). The vast majority of PIR sensors use a larger infrared receiver, a processing chip (sometimes integrated into the receiver) and a lens. However, this makes them kinda chunky. Also most have a digital, or maybe analog signal output - which makes them very simple.

The Adafruit STHS34PF80 IR Presence / Motion Sensor is like a deluxe version of the classic PIR sensor in that it has an IR sensing element that works up to 4 meters away and doesn't require a lens, which makes it easier to integrate into small enclosures. It also comes with a full I2C interface so you can get detailed information about how much IR was detected, and whether there's presence, movement, or temperature changes.

Nice sensor right? So we made it easy for you to get right into your next project. The surface-mount sensor is soldered onto a PCB and comes with a 3.3V regulator and level shifting so you can use it with a 3V or 5V logic microcontroller or single board computer without worry.

The custom made PCB is in the STEMMA QT form factor, making them easy to interface with. The STEMMA QT connectors on either side are compatible with the SparkFun Qwiic I2C connectors. This allows you to make solderless connections between your development board and the STHS34PF80 or to chain it with a wide range of other sensors and accessories using a compatible cable. QT Cable is not included, but we have a variety in the shop

Page last edited October 22, 2025

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Pinouts

The default I2C address is 0x5A.

Power Pins

VIN - this is the power pin. It can be powered by 3V or 5V. Give it the same power as the logic level of your microcontroller - e.g. for a 5V micro like Arduino, use 5V.
3Vo - this is the 3.3V output from the voltage regulator, you can grab up to 100mA from this if you like.
GND - common ground for power and logic.

I2C Logic Pins

SCL - I2C clock pin, connect to your microcontroller's I2C clock line. This pin can use 3-5V logic, and there's a 10K pullup on this pin.
SDA - I2C data pin, connect to your microcontroller's I2C data line. This pin can use 3-5V logic, and there's a 10K pullup on this pin.
STEMMA QT - These connectors allow you to connect to development boards with STEMMA QT (Qwiic) connectors or to other things with various associated accessories.

Interrupt Pin

INT - This is the interrupt pin. Its polarity and output type can be set in software over I2C.

Power LED and Jumper

Power LED - In the upper left corner, above the STEMMA connector, on the front of the board, is the power LED, labeled on. It is a green LED.
LED jumper - This jumper is located on the back of the board and is labeled LED on the board silk. Cut the trace on this jumper to cut power to the "on" LED.

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CircuitPython and Python

It's easy to use the STHS34PF80 breakout with Python or CircuitPython, and the Adafruit_CircuitPython_STHS34PF80 module. This module allows you to easily write Python code to read ambient and object temperatures with the sensor.

You can use this driver with any CircuitPython microcontroller board or with a computer that has GPIO and Python thanks to Adafruit_Blinka, our CircuitPython-for-Python compatibility library.

CircuitPython Microcontroller Wiring

First wire up the breakout to your board exactly as follows. The following is the sensor wired to a Feather RP2040 using the STEMMA connector:

Board STEMMA 3V to breakout STEMMA VIN (red wire)
Board STEMMA GND to breakout STEMMA GND (black wire)
Board STEMMA SCL to breakout STEMMA SCL (yellow wire)
Board STEMMA SDA to breakout STEMMA SDA (blue wire)

The following is the breakout wired to a Feather RP2040 using a solderless breadboard:

Board 3V to breakout VIN (red wire)
Board GND to breakout GND (black wire)
Board SCL to breakout SCL (yellow wire)
Board SDA to breakout SDA (blue wire)

Python Computer Wiring

Since there are dozens of Linux computers/boards you can use, we will show wiring for Raspberry Pi. For other platforms, please visit the guide for CircuitPython on Linux to see whether your platform is supported.

Here's the Raspberry Pi wired with I2C using the STEMMA connector:

Pi 3V to breakout STEMMA VIN (red wire)
Pi GND to breakout STEMMA GND (black wire)
Pi SCL to breakout STEMMA SCL (yellow wire)
Pi SDA to breakout STEMMA SDA (blue wire)

Here's the Raspberry Pi wired with I2C using a solderless breadboard:

Pi 3V to breakout VIN (red wire)
Pi GND to breakout GND (black wire)
Pi SCL to breakout SCL (yellow wire)
Pi SDA to breakout SDA (blue wire)

Python Installation of STHS34PF80 Library

You'll need to install the Adafruit_Blinka library that provides the CircuitPython support in Python. This may also require enabling I2C on your platform and verifying you are running Python 3. Since each platform is a little different, and Linux changes often, please visit the CircuitPython on Linux guide to get your computer ready!

Once that's done, from your command line run the following command:

pip3 install adafruit-circuitpython-sths34pf80

If your default Python is version 3 you may need to run 'pip' instead. Just make sure you aren't trying to use CircuitPython on Python 2.x, it isn't supported!

CircuitPython Usage

To use with CircuitPython, you need to first install the Adafruit_CircuitPython_STHS34PF80 library, and its dependencies, into the lib folder on your CIRCUITPY drive. Then you need to update code.py with the example script.

Thankfully, we can do this in one go. In the example below, click the Download Project Bundle button below to download the necessary libraries and the code.py file in a zip file. Extract the contents of the zip file, and copy the entire lib folder and the code.py file to your CIRCUITPY drive.

Your CIRCUITPY/lib folder should contain the following folders and file:

adafruit_bus_device/
adafruit_register/
adafruit_sths34pf80.mpy

Python Usage

Once you have the library pip3 installed on your computer, copy or download the following example to your computer, and run the following, replacing code.py with whatever you named the file:

python3 code.py

Example Code

If running CircuitPython: Once everything is saved to the CIRCUITPY drive, connect to the serial console to see the data printed out!

If running Python: The console output will appear wherever you are running Python.

Download Project Bundle

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# SPDX-FileCopyrightText: Copyright (c) 2025 Liz Clark for Adafruit Industries
#
# SPDX-License-Identifier: MIT

"""
Simple test example for the STHS34PF80 IR presence and motion sensor
"""

import time

import board

import adafruit_sths34pf80

# Create I2C bus
i2c = board.I2C()

# Create sensor instance
sensor = adafruit_sths34pf80.STHS34PF80(i2c)

print("-" * 40)

while True:
    # wait for new data
    if sensor.data_ready:
        # temperature values
        ambient_temp = sensor.ambient_temperature
        object_temp = sensor.object_temperature
        comp_object_temp = sensor.compensated_object_temperature

        # detection values
        presence_val = sensor.presence_value
        motion_val = sensor.motion_value
        temp_shock_val = sensor.temperature_shock_value

        # detection true/false
        presence = sensor.presence
        motion = sensor.motion
        temp_shock = sensor.temperature_shock

        print(f"Ambient Temp: {ambient_temp:.2f}°C")
        print(f"Object Temp (raw): {object_temp}")
        print(f"Object Temp (compensated): {comp_object_temp}")
        print(f"Presence Value: {presence_val} {'[DETECTED]' if presence else ''}")
        print(f"Motion Value: {motion_val} {'[DETECTED]' if motion else ''}")
        print(f"Temp Shock Value: {temp_shock_val} {'[DETECTED]' if temp_shock else ''}")
        print("-" * 40)

# SPDX-FileCopyrightText: Copyright (c) 2025 Liz Clark for Adafruit Industries
#
# SPDX-License-Identifier: MIT

"""
Simple test example for the STHS34PF80 IR presence and motion sensor
"""

import time

import board

import adafruit_sths34pf80

# Create I2C bus
i2c = board.I2C()

# Create sensor instance
sensor = adafruit_sths34pf80.STHS34PF80(i2c)

print("-" * 40)

while True:
    # wait for new data
    if sensor.data_ready:
        # temperature values
        ambient_temp = sensor.ambient_temperature
        object_temp = sensor.object_temperature
        comp_object_temp = sensor.compensated_object_temperature

        # detection values
        presence_val = sensor.presence_value
        motion_val = sensor.motion_value
        temp_shock_val = sensor.temperature_shock_value

        # detection true/false
        presence = sensor.presence
        motion = sensor.motion
        temp_shock = sensor.temperature_shock

        print(f"Ambient Temp: {ambient_temp:.2f}°C")
        print(f"Object Temp (raw): {object_temp}")
        print(f"Object Temp (compensated): {comp_object_temp}")
        print(f"Presence Value: {presence_val} {'[DETECTED]' if presence else ''}")
        print(f"Motion Value: {motion_val} {'[DETECTED]' if motion else ''}")
        print(f"Temp Shock Value: {temp_shock_val} {'[DETECTED]' if temp_shock else ''}")
        print("-" * 40)

View on GitHub

First, the STHS34PF80 sensor is recognized over I2C. Then, in the loop, it prints out the ambient temperature, presence detection and motion detection data.

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Arduino

Using the STHS34PF80 breakout with Arduino involves wiring up the breakout to your Arduino-compatible microcontroller, installing the Adafruit_STHS34PF80 library, and running the provided example code.

Wiring

Wire as shown for a 5V board like an Uno. If you are using a 3V board, like an Adafruit Feather, wire the board's 3V pin to the sensor VIN.

Here is an Adafruit Metro wired up to the sensor using the STEMMA QT connector:

Board 5V to breakout VIN (red wire)
Board GND to breakout GND (black wire)
Board SCL to breakout SCL (yellow wire)
Board SDA to breakout SDA (blue wire)

Here is an Adafruit Metro wired up using a solderless breadboard:

Board 5V to breakout VIN (red wire)
Board GND to breakout GND (black wire)
Board SCL to breakout SCL (yellow wire)
Board SDA to breakout SDA (blue wire)

Library Installation

You can install the Adafruit_STHS34PF80 library for Arduino using the Library Manager in the Arduino IDE.

Click the Manage Libraries ... menu item, search for Adafruit STHS34PF80, and select the Adafruit STHS34PF80 library:

If asked about dependencies, click "Install all".

If the "Dependencies" window does not come up, then you already have the dependencies installed.

If the dependencies are already installed, you must make sure you update them through the Arduino Library Manager before loading the example!

Example Code

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// Basic test for STHS34PF80 infrared sensor

#include "Adafruit_STHS34PF80.h"

Adafruit_STHS34PF80 sths;

void setup() {
  Serial.begin(115200);
  while (!Serial) delay(10);

  Serial.println("Adafruit STHS34PF80 test!");

  if (!sths.begin()) {
    Serial.println("Could not find a valid STHS34PF80 sensor, check wiring!");
    while (1) delay(10);
  }

  Serial.println("STHS34PF80 Found!");
}

void loop() {
  if (!sths.isDataReady()) {
    delay(10);
    return;
  }
  
  Serial.print("Data ready! ");
  
  // Read temperature data
  Serial.print("Amb: ");
  Serial.print(sths.readAmbientTemperature(), 2);
  Serial.print("°C");
  
  // Check for presence and show data if detected
  if (sths.isPresence()) {
    Serial.print(" PRESENCE: ");
    Serial.print(sths.readPresence());
  }
  
  // Check for motion and show data if detected
  if (sths.isMotion()) {
    Serial.print(" MOTION: ");
    Serial.print(sths.readMotion());
  }
  
  // Check for temperature shock and show data if detected
  if (sths.isTempShock()) {
    Serial.print(" TEMP_SHOCK: ");
    Serial.print(sths.readTempShock());
  }
  
  // Show object temperatures only if presence or motion detected
  if (sths.isPresence() || sths.isMotion()) {
    Serial.print(" Obj: ");
    Serial.print(sths.readObjectTemperature());
    Serial.print(", Comp: ");
    Serial.print(sths.readCompensatedObjectTemperature());
  }
  
  Serial.println();
  delay(100);
}

// Basic test for STHS34PF80 infrared sensor

#include "Adafruit_STHS34PF80.h"

Adafruit_STHS34PF80 sths;

void setup() {
  Serial.begin(115200);
  while (!Serial) delay(10);

  Serial.println("Adafruit STHS34PF80 test!");

  if (!sths.begin()) {
    Serial.println("Could not find a valid STHS34PF80 sensor, check wiring!");
    while (1) delay(10);
  }

  Serial.println("STHS34PF80 Found!");
}

void loop() {
  if (!sths.isDataReady()) {
    delay(10);
    return;
  }
  
  Serial.print("Data ready! ");
  
  // Read temperature data
  Serial.print("Amb: ");
  Serial.print(sths.readAmbientTemperature(), 2);
  Serial.print("°C");
  
  // Check for presence and show data if detected
  if (sths.isPresence()) {
    Serial.print(" PRESENCE: ");
    Serial.print(sths.readPresence());
  }
  
  // Check for motion and show data if detected
  if (sths.isMotion()) {
    Serial.print(" MOTION: ");
    Serial.print(sths.readMotion());
  }
  
  // Check for temperature shock and show data if detected
  if (sths.isTempShock()) {
    Serial.print(" TEMP_SHOCK: ");
    Serial.print(sths.readTempShock());
  }
  
  // Show object temperatures only if presence or motion detected
  if (sths.isPresence() || sths.isMotion()) {
    Serial.print(" Obj: ");
    Serial.print(sths.readObjectTemperature());
    Serial.print(", Comp: ");
    Serial.print(sths.readCompensatedObjectTemperature());
  }
  
  Serial.println();
  delay(100);
}

View on GitHub

Upload the sketch to your board and open up the Serial Monitor (Tools -> Serial Monitor) at 115200 baud. You'll see the STHS34PF80 recognized over I2C. Then, the ambient temperature, presence detection and motion detection are printed to the Serial Monitor.