We stock a large number of barometric pressure sensors, and they all have slight differences: some are ported, some are tiny, some are popular and precise and some are low cost. The Adafruit LPS28 (LPS28DFW) Pressure Sensor is unique in that it can handle a much higher range of pressures: almost every other sensor we've encountered tops out at about 1260 hPa. That means they're totally fine for measuring altitude for most human endeavors, we tend to stay above sea level. However, for some scientific or deep-water uses, 1260 will not cut it! That's why we're happy to stock a sensor that can go down to 4060 hPa - that's as low as -43,000 feet below sea level in air or 40 meters underwater.

We covered the LPS28DFW sensor on our EYE ON NPI video segment, and liked it so much we turned it into a product!

That makes this a good sensor for use with underwater devices or robots, as it can tell your depth from the pressure readings. Of course, its also still a great sensor for altitude sensing out of the water: with a 24-bit sensor and the ability to discern absolute pressure changes of ±0.5 hPa at the highest quality readings, good for less than 1 centimeter of altitude. (Like all pressure sensors, the actual altitude-above-sea-level depends on the days' pressure at sea level) Or, if you need speed, it can do up to 200 samples per second, without filtering and averaging.

The sensor comes with a little metal port, so you could connect a thin tubing to it for measuring pressure far from where it is soldered. The sensor element within the package has potting gel good up to 10,000 hPa of pressure and protection against some harsh chemicals - check the datasheet for more information to make sure you can use it to measure pressure of the liquid or gas you need.

To make life easier when working with this fancy sensor, we've taken the LPS28 and put it onto a breakout PCB along with support circuitry to let you use this little wonder with 3.3V (Feather/Raspberry Pi) or 5V (Arduino/ Metro328) logic levels.

Additionally, since it speaks I2C, you can easily connect it up with two wires (plus power and ground!). We've even included SparkFun qwiic compatible STEMMA QT connectors for the I2C bus so you don't even need to solder! Just wire up to your favorite micro and you can use our CircuitPython/Python or Arduino drivers to easily interface with the LPS28 and make approximate approximations of proximity in no time! QT Cable is not included, but we have a variety in the shop.

The default I2C address is 0x5C.

Power Pins

• VIN - this is the power pin. To power the board, 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 dev boards with STEMMA QT (qwiic) connectors or to other things with various associated accessories

Interrupt Pin

• INT - This is the interrupt pin. The default state is active high. You can change the state in software.

Power LED and LED 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, labeled LED on the board silk, is located on the back of the board, in the upper right corner. Cut the trace on this jumper to cut power to the "on" LED.

SA0 Jumper

• SA0 - On the back of the board, towards the center, is the I2C address jumper. It is labeled SA0 on the board silk. If you solder this jumper closed, you'll change the I2C address from the default 0x5C to 0x5D.

It's easy to use the LPS28 with Python or CircuitPython, and the Adafruit_CircuitPython_LPS28 module. This module allows you to easily write Python code to read pressure and temperature data.

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

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

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:

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

Python Installation of LPS28 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-lps28

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_LPS28 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_lps28.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.

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

import time

import board

import adafruit_lps28

i2c = board.I2C()
sensor = adafruit_lps28.LPS28(i2c)

# Data Rate in hz
# 1, 4, 10, 25, 50, 75, 100 or 200 (default)
# sensor.data_rate = 200

# Number of samples to average per measurement
# 4 (default), 8, 16, 32, 64, 128, 512
# sensor.averaging = 4

# Full scale measurement mode for pressure
# (False = 1260 hPa, True = 4060 hPa (default))
# sensor.full_scale_mode = True

# Enable/Disable Interrupts Defaults

# sensor.data_ready_int = True # Data Ready Interrupt
# sensor.data_ready_pulse = False # Data-ready interrupt as a pulse
# sensor.fifo_full_int = False # FIFO full interrupt
# sensor.fifo_overrun_int = False # FIFO overrun interrupt
# sensor.fifo_watermark_int = False # FIFO watermark interrupt

print("LPS28 Simple Test")
print("-" * 40)

while True:
    if sensor.data_ready:
        print(f"Pressure: {sensor.pressure:.1f} hPa")
        print(f"Temperature: {sensor.temperature:.1f} °C")
        print("-" * 40)

    time.sleep(0.5)

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

import time

import board

import adafruit_lps28

i2c = board.I2C()
sensor = adafruit_lps28.LPS28(i2c)

# Data Rate in hz
# 1, 4, 10, 25, 50, 75, 100 or 200 (default)
# sensor.data_rate = 200

# Number of samples to average per measurement
# 4 (default), 8, 16, 32, 64, 128, 512
# sensor.averaging = 4

# Full scale measurement mode for pressure
# (False = 1260 hPa, True = 4060 hPa (default))
# sensor.full_scale_mode = True

# Enable/Disable Interrupts Defaults

# sensor.data_ready_int = True # Data Ready Interrupt
# sensor.data_ready_pulse = False # Data-ready interrupt as a pulse
# sensor.fifo_full_int = False # FIFO full interrupt
# sensor.fifo_overrun_int = False # FIFO overrun interrupt
# sensor.fifo_watermark_int = False # FIFO watermark interrupt

print("LPS28 Simple Test")
print("-" * 40)

while True:
    if sensor.data_ready:
        print(f"Pressure: {sensor.pressure:.1f} hPa")
        print(f"Temperature: {sensor.temperature:.1f} °C")
        print("-" * 40)

    time.sleep(0.5)

First, the sensor is instantiated over I2C. Then, in the loop, the pressure and temperature readings are printed to the serial monitor.

Using the LPS28 breakout with Arduino involves wiring up the breakout to your Arduino-compatible microcontroller, installing the Adafruit_LPS28 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:

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

Library Installation

You can install the Adafruit_LPS28 library for Arduino using the Library Manager in the Arduino IDE.

Click the Manage Libraries ... menu item, search for Adafruit_LPS28, and select the Adafruit LPS28 library:

If asked about dependencies, click "Install all".

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

Example Code

#include <Wire.h>
#include <Adafruit_LPS28.h>

// Instantiate the sensor
Adafruit_LPS28 lps28;

void setup() {
  Serial.begin(115200);
  while (!Serial) delay(10); // Wait for Serial monitor

  Serial.println("LPS28 Test");

  // Initialize the sensor
  if (!lps28.begin()) {
    Serial.println("Failed to find LPS28 sensor!");
    while (1) delay(10);
  }

  Serial.println("LPS28 sensor found!");

  // Set the highest ODR (200 Hz) and 4-sample averaging, new value every 20ms
  lps28.setDataRate(LPS28_ODR_200_HZ);
  lps28.setAveraging(LPS28_AVG_4);

  // Set range to 4060 hPa
  lps28.setFullScaleMode(true);

  // Enable DRDY interrupt on the interrupt pin
  lps28.setInterruptPin(
    true,  // Polarity: Active high
    false  // Pin mode: Push-pull
  );

  // Enable DRDY interrupt output on INT pin (we could use this with an interrupt)
  lps28.setIntPinOutput(
    true,  // DRDY active
    false, // DRDY pulse not enabled
    false, // INT output not enabled
    false, // FIFO full interrupt not enabled
    false, // FIFO watermark interrupt not enabled
    false  // FIFO overrun interrupt not enabled
  );
}

void loop() {
  // Check if data is ready by reading the STATUS register
  if (lps28.getStatus() & LPS28_STATUS_PRESS_READY) { // Pressure data available
    // Read and print pressure and temperature
    float pressure = lps28.getPressure();
    float temperature = lps28.getTemperature();

    Serial.print("Pressure (hPa): ");
    Serial.println(pressure);

    Serial.print("Temperature (°C): ");
    Serial.println(temperature);
  }

  delay(10); // Polling delay
}

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#include <Wire.h>
#include <Adafruit_LPS28.h>

// Instantiate the sensor
Adafruit_LPS28 lps28;

void setup() {
  Serial.begin(115200);
  while (!Serial) delay(10); // Wait for Serial monitor

  Serial.println("LPS28 Test");

  // Initialize the sensor
  if (!lps28.begin()) {
    Serial.println("Failed to find LPS28 sensor!");
    while (1) delay(10);
  }

  Serial.println("LPS28 sensor found!");

  // Set the highest ODR (200 Hz) and 4-sample averaging, new value every 20ms
  lps28.setDataRate(LPS28_ODR_200_HZ);
  lps28.setAveraging(LPS28_AVG_4);

  // Set range to 4060 hPa
  lps28.setFullScaleMode(true);

  // Enable DRDY interrupt on the interrupt pin
  lps28.setInterruptPin(
    true,  // Polarity: Active high
    false  // Pin mode: Push-pull
  );

  // Enable DRDY interrupt output on INT pin (we could use this with an interrupt)
  lps28.setIntPinOutput(
    true,  // DRDY active
    false, // DRDY pulse not enabled
    false, // INT output not enabled
    false, // FIFO full interrupt not enabled
    false, // FIFO watermark interrupt not enabled
    false  // FIFO overrun interrupt not enabled
  );
}

void loop() {
  // Check if data is ready by reading the STATUS register
  if (lps28.getStatus() & LPS28_STATUS_PRESS_READY) { // Pressure data available
    // Read and print pressure and temperature
    float pressure = lps28.getPressure();
    float temperature = lps28.getTemperature();

    Serial.print("Pressure (hPa): ");
    Serial.println(pressure);

    Serial.print("Temperature (°C): ");
    Serial.println(temperature);
  }

  delay(10); // Polling delay
}

Upload the sketch to your board and open up the Serial Monitor (Tools -> Serial Monitor) at 115200 baud. You'll see the LPS28 recognized over I2C. Then, pressure and temperature readings will be printed to the Serial Monitor. 

What is WipperSnapper

WipperSnapper is a firmware designed to turn any WiFi-capable board into an Internet-of-Things device without programming a single line of code. WipperSnapper connects to Adafruit IO, a web platform designed (by Adafruit!) to display, respond, and interact with your project's data.

Simply load the WipperSnapper firmware onto your board, add credentials, and plug it into power. Your board will automatically register itself with your Adafruit IO account.

From there, you can add components to your board such as buttons, switches, potentiometers, sensors, and more! Components are dynamically added to hardware, so you can immediately start interacting, logging, and streaming the data your projects produce without writing code.

If you've never used WipperSnapper, click below to read through the quick start guide before continuing.

Wiring

First, wire up an LPS28 (LPS28DFW) to your board exactly as follows. Here is an example of the LPS28 wired to an Adafruit ESP32 Feather V2 using I2C with a STEMMA QT cable (no soldering required)

Usage

Connect your board to Adafruit IO Wippersnapper and navigate to the WipperSnapper board list.

On this page, select the WipperSnapper board you're using to be brought to the board's interface page.

If you do not see your board listed here - you need to connect your board to Adafruit IO first.

Next, make sure the sensor is plugged into your board and click the I2C Scan button.

You should see the LPS28's default I2C address of 0x5C pop-up in the I2C scan list.

With the sensor detected in an I2C scan, you're ready to add the sensor to your board.

Click the New Component button or the + button to bring up the component picker.

Adafruit IO supports a large amount of components. To quickly find your sensor, type LPS28 into the search bar, then select the LPS28 component.

On the component configuration page, the LPS28's sensor address should be listed along with the sensor's settings.

The Send Every option is specific to each sensor's measurements. This option will tell the Feather how often it should read from the LPS28 sensor and send the data to Adafruit IO. Measurements can range from every 30 seconds to every 24 hours.

For this example, set the Send Every interval to every 30 seconds.

Your device interface should now show the sensor components you created. After the interval you configured elapses, WipperSnapper will automatically read values from the sensor(s) and send them to Adafruit IO.

To view the data that has been logged from the sensor, click on the graph next to the sensor name.

Here you can see the feed history and edit things about the feed such as the name, privacy, webhooks associated with the feed and more. If you want to learn more about how feeds work, check out this page.

Files

• LPS28DFW Datasheet
• EagleCAD PCB Files on GitHub
• Fritzing object in the Adafruit Fritzing Library

Schematic and Fab Print