ENV-III Unit

In this article we look at an add-on hat for the M5StickC and M5StickC-plus called the ENV 3 sensor.

The env 3 hat is able to detect the temperature, humidity and air pressure.

This product relates via I2C protocol which allows you to obtain 3 types of environment data thru just 2 pins, together with the tiny body, makes it a powerful application for environment data collecting.

The sensor comes with a cable for connecting it to the m5stick base unit

It comprises of the following sensors

SHT30 : SHT30 is a high-precision and low-power digital temperature and humidity sensor

QMP6988 : QMP6988 is an absolute air pressure sensor specially designed for mobile applications, with high accuracy and stability, suitable for environmental data collection and detection types of projects.

 

Specification

Purchase

Layout

I used the grove port to connect the sensor to the M5StickC

Code

For Arduino development you need to add ESP32 support via the board manager by adding the following ESP32 Boards Manager url to the Additional Boards Manager URLs:

https://dl.espressif.com/dl/package_esp32_index.json

Once all of the required files are downloaded then you need to Navigate to Tools->Board:->Boards Manager and then Search ESP32 in the pop-up window, find it and click Install

Under Tools->Board:-> ESP32 Arduino you will see M5Stick-C in the list

You can then install the MStickC library like this

Open Arduino IDE, then Select Sketch->Include Library->Manage Libraries. Search M5StickC , find it and click Install.

You can find the example below under examples -> Unit -> ENVIII_SHT30_QMP6988

[codesyntax lang=”cpp”]

#include <M5StickC.h>
#include "Adafruit_Sensor.h"
#include <Adafruit_BMP280.h>
#include "UNIT_ENV.h"

SHT3X sht30;
QMP6988 qmp6988;

float tmp = 0.0;
float hum = 0.0;
float pressure = 0.0;

void setup() {
  M5.begin(); //Init M5StickC.  初始化M5StickC
  M5.Lcd.setRotation(3);  //Rotate the screen. 
  Wire.begin(); //Wire init, adding the I2C bus.
  qmp6988.init();
  M5.lcd.println(F("ENV Unit III test"));
}

void loop() {
  pressure = qmp6988.calcPressure();
  if(sht30.get()==0){ //Obtain the data of shT30.  获取sht30的数据
    tmp = sht30.cTemp;  //Store the temperature obtained from shT30.  
    hum = sht30.humidity; //Store the humidity obtained from the SHT30. 
  }else{
    tmp=0,hum=0;
  }
  M5.lcd.fillRect(0,20,100,60,BLACK); //Fill the screen with black (to clear the screen)
  M5.lcd.setCursor(0,20);
  M5.Lcd.printf("Temp: %2.1f  \r\nHumi: %2.0f%%  \r\nPressure:%2.0fPa\r\n", tmp, hum, pressure);
  delay(2000);
}

[/codesyntax]

When you run this it should display various readings on the display

 

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