Weather Station With A7670 -- Remote Monitoring

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 2pm 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 support 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 moisturiser 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

• Insert the SIM card into the slot on the back of the board

• Connect 0.96 OLED to Maduino Zero 4G LTE(CAT1 A7670) 's SCL and SDA;

• Connect Temperature and humidity sensor's data pin to Maduino Zero 4G LTE(CAT1 A7670) 's D6;

• Connect Photosensitive resistance module's data pin to Maduino Zero 4G LTE(CAT1 A7670) 's D8;

• Connect Wind Speed Transmitter's data pin to Maduino Zero 4G LTE(CAT1 A7670) 's A0;

Step 2: Firmware about sensor

• At first, we need to prepare the environment for ESP32 development board programming in arduino, and you can cheak 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>

• Difine 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);

• Initialise 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);

   

    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();

Step 3: 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 out 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 4: Firmware about LTE

• Using HTTP(S) AT Commands, accessing to HTTP server,

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);

• Controlling LTE Access to Write Channel URLs Using AT Commands, continuously sends data to the site on wind speed, temperature, humidity, and the presence or absence of bright light.

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);

Step 5: Result

From the private viewing interface of ThingSpeak, we can monitor the weather of the office cubicle in real time, for example, right now, it shows that the light is relatively strong, so I'd better put on sunscreen and go out, the humidity is low, so I have to put on moisturiser, the temperature is good and there is no wind, so I wear a moderately thick long-sleeved shirt, now, let's leave to work happily.