MPL3115A2 pressure sensor readings on LCD

arduino and lcd keypad shield and TMP102 layout

In this project we will get the current altitude and temperature using an MPL3115A2 pressure sensor connected to an LCD keypad shield fitted to an Arduino Uno

Here is a little information regarding the sensor.

The MPL3115A2 is a compact, piezoresistive, absolute pressure sensor with an I2C digital interface. MPL3115A2 has a wide operating range of 20 kPa to 110 kPa, a range that covers all surface elevations on earth. The MEMS is temperature compensated utilizing an on-chip temperature sensor. The pressure and temperature data is fed into a high resolution ADC to provide fully compensated and digitized outputs for pressure in Pascals and temperature in °C.

The compensated pressure output can then be converted to altitude, utilizing the formula stated in Section 9.1.3 “Pressure/altitude” provided in meters.The internal processing in MPL3115A2 removes compensation and unit conversion load from the system MCU, simplifying system design

Parts List

I used the following parts for this project

Description	Link
Arduino Uno	1pcs UNO R3 CH340G+MEGA328P for Arduino UNO R3 (NO USB CABLE)
LCD Keypad shield	1PCS LCD Keypad Shield LCD 1602 Module Display For Arduino
MPL3115A2	MPL3115A2 I2C Intelligent Temperature Pressure Altitude Sensor V2.0 For Arduino
connecting wire	40pcs Dupont jumper wire cable 30cm male to male,female to female,male to female Dupont jump wire line 2.54mm breadboard cable

Schematics/Layout

lcd shield and MPL3115A2 layout

Code

We need to add a library via the library manager or download it from – https://github.com/adafruit/Adafruit_MPL3115A2_Library

Source code

#include <Wire.h>
#include <LiquidCrystal.h>
#include <Adafruit_MPL3115A2.h>
 
//setup for the LCD keypad shield
LiquidCrystal lcd(8, 9, 4, 5, 6, 7);
Adafruit_MPL3115A2 baro = Adafruit_MPL3115A2();
 
void setup() 
{
  //init serial for some debug
  Serial.begin(9600);
  Serial.println("Adafruit_MPL3115A2 test!");
 
  //init LCD
  lcd.begin(16,2);
  //line 1 - temperature
  lcd.setCursor(0,0);
  lcd.print("ALTITUDE");
  //line 2 - humidity
  lcd.setCursor(0,1);
  lcd.print("TEMPERATURE");
}
 
void loop() 
{
  if (! baro.begin()) 
  {
    Serial.println("Couldnt find sensor");
    return;
  }
  float pascals = baro.getPressure();
  float altm = baro.getAltitude();
  float tempC = baro.getTemperature();
  //display readings on lcd  
  lcd.setCursor(0,0);
  lcd.print("Alt = ");
  lcd.print(altm);
  lcd.print(" m");
  lcd.setCursor(0,1);
  lcd.print("Temp = ");
  lcd.print(tempC);
  lcd.print(" *c");
 
  delay(500);
}

Output

Here is a video showing my results, you should get similar results on your LCD

Links

https://www.nxp.com/docs/en/data-sheet/MPL3115A2.pdf

Arduino Projects

MPL3115A2 pressure sensor readings on LCD