STM32 Nucleo and LPS22HB absolute pressure sensor example using the Arduino IDE

In this article we look at another absolute pressure sensor – this time its the LPS22HB and once again we will connect this to a STM32 nucleo

The LPS22HB is an ultra-compact piezoresistive absolute pressure sensor which functions as a digital output barometer. The device comprises a sensing element and an IC interface which communicates through I²C or SPI from the sensing element to the application.

The sensing element, which detects absolute pressure, consists of a suspended membrane manufactured using a dedicated process developed by ST.
The LPS22HB is available in a full-mold, holed LGA package (HLGA). It is guaranteed to operate over a temperature range extending from -40 °C to +85 °C. The package is holed to allow external pressure to reach the sensing element.

Features

260 to 1260 hPa absolute pressure range
Current consumption down to 3 μA
High overpressure capability: 20x full-scale
Embedded temperature compensation
24-bit pressure data output
16-bit temperature data output
ODR from 1 Hz to 75 Hz

SPI and I²C interfaces
Embedded FIFO
Interrupt functions: Data Ready, FIFO flags, pressure thresholds
Supply voltage: 1.7 to 3.6 V
High shock survivability: 22,000 g

Parts Required

Name	Link
NUCLEO-L496ZG	1/PCS LOT NUCLEO-L496ZG Nucleo development board STM32L4 series development board
LPS22HB	Semoic Lps22Hb Pressure Resistance Pressure Sensor Module for High Intensity Industrial Control
Connecting wire	Free shipping Dupont line 120pcs 20cm male to male + male to female and female to female jumper wire

Schematic/Connection

I used 3v3, there is a Vin pin and I could have quite easily used 5v

Nucleo	Sensor
3v3	3v3
Gnd	Gnd
I2C1_SCL	SCL
I2C1_SDA	SDA

Code Example

This uses the library from hhttps://github.com/adrien3d/IO_LPS22HB

/***************************************************************************
This is a library for the LPS22HB Absolute Digital Barometer

Designed to work with all kinds of LPS22HB Breakout Boards

These sensors use I2C, 2 pins are required to interface, as this :
VDD to 3.3V DC
SCL to A5
SDA to A4
GND to common groud

Written by Adrien Chapelet for IoThings
***************************************************************************/

#include <Wire.h>

#include "IO_LPS22HB.h"

IO_LPS22HB lps22hb;

void setup()
{
Serial.begin(9600);
Serial.println("IoThings LPS22HB Arduino Test");

lps22hb.begin(0x5D);

byte who_am_i = lps22hb.whoAmI();
Serial.print("Who Am I? 0x");
Serial.print(who_am_i, HEX);
Serial.println(" (expected: 0xB1)");
if (who_am_i != LPS22HB_WHO_AM_I_VALUE) {
Serial.println("Error while retrieving WHO_AM_I byte...");
while (true) {
// loop forever
}
}
}

void loop()
{
Serial.print("P=");
Serial.print(lps22hb.readPressure());
Serial.print(" mbar, T=");
Serial.print(lps22hb.readTemperature());
Serial.println("C");
delay(300);
}

Output

Open the serial monitor and you should see something like this

IoThings LPS22HB Arduino Test
Who Am I? 0xB1 (expected: 0xB1)
P=954.86 mbar, T=27.43C
P=954.91 mbar, T=27.40C
P=954.86 mbar, T=27.37C
P=954.88 mbar, T=27.34C
P=954.89 mbar, T=27.34C
P=954.88 mbar, T=27.33C
P=954.90 mbar, T=27.27C
P=954.87 mbar, T=27.22C

Links

https://www.st.com/resource/en/datasheet/lps22hb.pdf