Introduction: Weather Station With A7670 -- Remote Monitoring

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Hi everyone! Our company moved to a new location due to environmental issues. After moving to the new address, I was a little uncomfortable because the sun always shone strongly on my office cubicle at 2 pm every day, and the weather was also a little dry, but I wasn't prepared for this before I left for work.

So I'm going to make a weather station with Maduino Zero 4G LTE(CAT1 A7670), which supports HTTP and can transfer data to the web page. When I put it on my office cubicle, I will know what the office cubicle weather is from the webpage at home, so I can be ready to deal with it before I go out, can know if I should wear thick clothes, put on moisturizer or not, and bring sunscreen or not.

Supplies

  • 1 x Maduino Zero 4G LTE(CAT1 A7670)
  • 1 x Temperature and humidity sensor
  • 1 x Photosensitive resistance module
  • 1 x Wind Speed Transmitter
  • 1 x 0.96 OLED
  • 1 x SIM card

Step 1: Hardware

Step 2: ThingSpeak

ThingSpeak Is The Open IoT Platform With MATLAB Analytics.

  • Register and log in to your account
  • Define the parameter you want in the Channel page and save it
  • On the API keys page, you can find the API key used to write the data, and you can see an example of an API request on the right.
  • By accessing the URL of the write channel, you can modify the parameters

Step 3: Firmware

  • First, we need to prepare the environment for ESP32 development board programming in Arduino, and you can check this guide.
  • This is a library for our Monochrome OLEDs based on SSD1306 drivers.
#include <Adafruit_SSD1306.h>
  • This library allows you to communicate with I2C devices (the OLED is connected by I2C)
#include <Wire.h>
  • The Adafruit_GFX library provides a common syntax and set of graphics functions for all of our LCD and OLED displays and LED matrices.
#include <Adafruit_GFX.h>
  • An Arduino library for the DHT series.
#include <DHT.h>
  • Define your pins, this determines which pin of the board your device should be connected to.
#define DEBUG true
#define LTE_RESET_PIN 6
#define LTE_PWRKEY_PIN 5
#define pinInterrupt A0
#define DHTPIN 2
#define LIGHT
  • Configuring OLEDs.
#define SCREEN_WIDTH 128 // OLED display width, in pixels
#define SCREEN_HEIGHT 64 // OLED display height, in pixels
#define OLED_RESET -1    // Reset pin # (or -1 if sharing Arduino reset pin)
#define SCREEN_ADDRESS 0x3c
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);
  • Initialize your devices so that they work properly
    SerialUSB.begin(115200);
    Serial1.begin(115200);

    pinMode(LTE_RESET_PIN, OUTPUT);
    digitalWrite(LTE_RESET_PIN, LOW);

    pinMode(LTE_PWRKEY_PIN, OUTPUT);
    digitalWrite(LTE_RESET_PIN, LOW);
    delay(100);
    digitalWrite(LTE_PWRKEY_PIN, HIGH);
    delay(3000);
    digitalWrite(LTE_PWRKEY_PIN, LOW);

    SerialUSB.println("Maduino Zero 4G LTE CAT1 Test Start!"); 
    SerialUSB.println("Wait a few minutes for 4G star");
    delay(3000);   
    sendData("AT", 1000, DEBUG);
    delay(5000);
    sendData("AT+CICCID", 1000, DEBUG);
    delay(5000);
    sendData("AT+SIMCOMATI", 1000, DEBUG);
    delay(5000);
    sendData("AT+COPS?", 1000, DEBUG); 
    delay(5000);
    sendData("AT+CPIN?", 3000, DEBUG);
    delay(5000);
    sendData("AT+CSQ", 1000, DEBUG);
    delay(5000);
    sendData("AT+CREG?", 1000, DEBUG);
    delay(5000);
    sendData("AT+CGREG?", 1000, DEBUG);
    delay(5000);
    sendData("AT+CPSI?", 1000, DEBUG);
    delay(5000);
    sendData("AT+CGDCONT=1,\"IP\",\"CMNET\"", 1000, DEBUG);
    delay(5000);
    sendData("AT+CGATT=1", 1000, DEBUG);
    delay(5000);
    sendData("AT+HTTPINIT", 1000, DEBUG);
    delay(5000);
    sendData("AT+HTTPPARA=\"URL\",\"http://api.thingspeak.com/update?api_key="+Apikey+"\"\r\n", 2000, DEBUG);
    delay(5000);
    sendData("AT+HTTPACTION=0\r\n", 3000, DEBUG);
    delay(5000);
    sendData("AT+HTTPTERM\r\n", 3000, DEBUG);
    delay(5000);

    Wire.begin();
    if (!display.begin(SSD1306_SWITCHCAPVCC, SCREEN_ADDRESS)) {
        SerialUSB.println(F("SSD1306 allocation failed"));
        for (;;); // Don't proceed, loop forever
    }
    else{
      SerialUSB.println(F("SSD1306 allocation successful"));
    }
    display.clearDisplay();
    delay(1000);

    pinMode(pinInterrupt, INPUT_PULLUP);
    attachInterrupt(digitalPinToInterrupt(pinInterrupt), onChange, FALLING); 
    dht.begin();
    pinMode(LIGHT, INPUT);
  • Detecting wind speed
    void wind_speed()
    {
      lastDebounceTime = millis();
      Count = 0;
      while(!((millis() - lastDebounceTime) > debounceDelay));
      if ((millis() - lastDebounceTime) > debounceDelay)
      {


        speed_value = Count * 8.75 * 0.01;
         SerialUSB.print("Wind speed:");
         SerialUSB.print(speed_value);    
         SerialUSB.println("m/s");
        Count = 0;
      }
    }

    void onChange()
    {
      if (digitalRead(pinInterrupt) == LOW)
        Count++;
    }
  • Detecting light intensity
    void light_str()
    {
       lastDebounceTime = millis();
      count_light = 0;
      while((millis() - lastDebounceTime) < debounceDelay)
      {
          delay(5);
          if (digitalRead(LIGHT) == 0){
            count_light++;
          }
      }
          if(count_light>100)
          {
            SerialUSB.println("Strong ultraviolet ray");
            light_intensity =light_intensity +"Strong ultraviolet ray";
            light_index = light_index + "1";
          }
          else
          {
            SerialUSB.println("Weak ultraviolet ray");
            light_intensity =light_intensity + "Weak ultraviolet ray";
            light_index = light_index + "0";
          }
          count_light = 0;
      }
  • Detecting temperature and humidity
   float humidity_value = dht.readHumidity();
   float temperature_value = dht.readTemperature();
   SerialUSB.print("Humidity:");
   SerialUSB.print(humidity_value);
   SerialUSB.println(" %");
   SerialUSB.print("Temperature:");
   SerialUSB.print(temperature_value);
   SerialUSB.println(" C");
  • OLED display information

    display.clearDisplay();
    display.setCursor(1, 5);
    display.setTextColor(WHITE);
    display.setTextSize(1);
    display.println("Humidity:" + String(humidity_value) + " %" );
    display.setCursor(1, 15);
    display.setTextColor(WHITE);
    display.setTextSize(1);
    display.println("Temperature:" + String(temperature_value) + " C" );
    display.setCursor(1, 25);
    display.setTextColor(WHITE);
    display.setTextSize(1);
    display.println("Wind speed:" + String(speed_value) + "m/s");
    display.setCursor(1, 35);
    display.setTextColor(WHITE);
    display.setTextSize(1);
    display.println(light_l);
    display.display();
  • Controlling LTE Access to Write Channel URLs Using AT Commands
 String http_str = "AT+HTTPPARA=\"URL\",\"http://api.thingspeak.com/update?api_key=" + Apikey + "&field1=" + String(speed_value)+"&field2=" +String(temperature_value) + "&field3="+ String(humidity_value)+"&field4="+light_index +"\"\r\n";
    sendData("AT+HTTPINIT\r\n", 2000, DEBUG);
    delay(5000);
    sendData(http_str, 2000, DEBUG);
    delay(5000);
    sendData("AT+HTTPACTION=0\r\n", 3000, DEBUG);
    delay(5000);
    sendData("AT+HTTPTERM\r\n", 3000, DEBUG);
    delay(5000);

Attachments

Step 4: Results

From the private viewing interface of ThingSpeak, we can monitor the weather of the office cubicle in real-time, for example, right now, it indicates that the light is relatively strong, so I'd better apply sunscreen, the humidity is also low, so I need to use moisturizer, the temperature is comfortable, and there is a light breeze, so I will wear a moderately thick long-sleeved shirt, now, let's leave to work happily.