> For the complete documentation index, see [llms.txt](https://docs.consentiumiot.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.consentiumiot.com/tutorials/receiving-sensor-data/receiving-sensor-data-from-consentium-iot-cloud-and-controlling-led.md).

# Receiving Sensor Data from Consentium IoT Cloud and Controlling LED

This documentation provides the steps and code required to receive data from the **Consentium IoT cloud** using the **ConsentiumThings** library. The code checks whether the first data pair (assumed to be temperature data) exceeds a threshold of 30°C and turns on an LED if the condition is met. This is intended for ESP8266, ESP32, or Raspberry Pi Pico W compatible boards.

### Dependencies

The code utilizes the `ConsentiumThings.h` library to handle communication with the Consentium IoT platform. Additionally, it uses GPIO pins to control an LED.

### Features

* Connect to a WiFi network for cloud communication.
* Receive sensor data from the Consentium IoT platform.
* Parse and display the received data on the serial monitor.
* Control an LED connected to a specific GPIO pin based on sensor data (temperature in this case).

### Hardware Setup

* **LED**: Connect the anode (positive leg) of an LED to **GPIO 16** on an ESP8266, **GPIO 23** on an ESP32, or **GPIO 25** on a Raspberry Pi Pico W.
* **Resistor**: Use a 220Ω resistor in series with the LED to limit current.

#### GPIO Pin Mapping for LED:

* **ESP8266**: GPIO 16
* **ESP32**: GPIO 23
* **Raspberry Pi Pico W**: GPIO 25

### Constants

* **WiFi Credentials**: Set your WiFi SSID and password.
* **Receive Interval**: The loop runs every 7 seconds (7000 ms) to retrieve data from the server.
* **API Keys**: Required to authenticate the connection to the Consentium IoT cloud.

### Code Overview

#### 1. Initialization

A `ConsentiumThings` the object is created to manage communication with the Consentium IoT platform.

```cpp
ConsentiumThings board; // Create ConsentiumThings object
```

WiFi credentials and API keys are declared:

```cpp
const char *ssid = "YOUR_WIFI_SSID"; // Add WiFi SSID
const char *pass = "YOUR_WIFI_PASSWORD"; // Add WiFi password
```

An LED is connected to the designated GPIO pin (D15 in the example) to indicate whether the temperature exceeds the threshold.

```cpp
#define LED_PIN 15  // Set the pin to which the LED is connected
```

#### 2. Setup

The `setup()` function establishes a WiFi connection, configures the IoT board to receive data, and initializes the LED pin as an output.

```cpp
void setup() {
  pinMode(LED_PIN, OUTPUT);  // Set the LED pin as an output
  digitalWrite(LED_PIN, LOW);  // Turn off the LED initially

  board.initWiFi(ssid, pass);  // Begin WiFi connection
  board.beginReceive(ReceiveApiKey, BoardApiKey);  // Initialize board to receive data from Consentium IoT cloud
}
```

#### 3. Main Loop

The `loop()` function receives sensor data from the cloud, displays it on the serial monitor, and checks if the 0th data pair (assumed to be temperature) exceeds 30°C. If so, it turns on the LED connected to D15; otherwise, the LED remains off.

**a. Receiving Data**

The sensor data is fetched from the Consentium IoT platform using the `receiveData()` function.

```cpp
auto dataPairs = board.receiveData();  // Receive sensor data from server
```

**b. Parsing Data**

The received data is stored in pairs (value and info), which are iterated through and printed on the serial monitor.

```cpp
for(size_t i = 0; i < dataPairs.size(); i++){
    double data = dataPairs[i].first; 
    String info = dataPairs[i].second.c_str();

    Serial.print("Data: ");
    Serial.print(data);
    Serial.print("          \t");
    Serial.print("Info: ");
    Serial.println(info);
}
```

**c. Testing Temperature and Controlling LED**

If the temperature (0th data pair) exceeds 30°C, the LED connected to **GPIO D15** is turned on.

```cpp
// Test the 0th data pair (temperature) against 30°C
if (dataPairs.size() > 0) {
  double temperature = dataPairs[0].first;  // Assume 0th data pair is temperature

  if (temperature > 30) {
    digitalWrite(LED_PIN, HIGH);  // Turn on LED if temperature > 30°C
  } else {
    digitalWrite(LED_PIN, LOW);   // Turn off LED if temperature <= 30°C
  }
}
```

#### 4. Loop Control

The loop repeats every 7000 milliseconds (7 seconds), allowing for periodic data retrieval.

```cpp
delay(interval);
```

### Full Code

```cpp
/***************************************************
  This is Consentium's IoT library
  ----> https://consentiuminc.online/
  Check out the links above for our tutorials and product diagrams.

  This Consentium's IoT library works only for ESP8266/ESP32/Raspberry Pi Pico W compatible Edge boards. 
  
  Connect a LED to GPIO 16 for ESP 8266, GPIO 23 for ESP 32 and GPIO 25 for Raspberry Pi Pico W to indicate the REST events. 
  
  Written by Debjyoti Chowdhury for Consentium.
  MIT license, all text above must be included in any redistribution
 ****************************************************/

#include <ConsentiumThings.h>

ConsentiumThings board; // Create ConsentiumThings object

const char *ssid = "YOUR_WIFI_SSID"; // Add WiFi SSID
const char *pass = "YOUR_WIFI_PASSWORD"; // Add WiFi password
constexpr int interval = 7000; // Wait for 7 seconds
const char *ReceiveApiKey = "YOUR_API_KEY"; // Receive API key
const char *BoardApiKey = "YOUR_BOARD_API_KEY"; // Board API key

#define LED_PIN 15  // Set the pin to which the LED is connected (D15)

void setup() {
  pinMode(LED_PIN, OUTPUT);  // Set the LED pin as an output
  digitalWrite(LED_PIN, LOW);  // Turn off the LED initially

  board.initWiFi(ssid, pass);  // Begin WiFi connection
  board.beginReceive(ReceiveApiKey, BoardApiKey);  // Initialize board to receive data from Consentium IoT cloud
}

void loop() {
  // Get sensor data from server
  auto dataPairs = board.receiveData(); 
  
  // Print sensor data from server
  for(size_t i = 0; i < dataPairs.size(); i++){
    double data = dataPairs[i].first; 
    String info = dataPairs[i].second.c_str();

    Serial.print("Data: ");
    Serial.print(data);
    Serial.print("          \t");
    Serial.print("Info: ");
    Serial.println(info);
  }
  Serial.println();

  // Test the 0th data pair (temperature) against 30°C
  if (dataPairs.size() > 0) {
    double temperature = dataPairs[0].first;  // Assume 0th data pair is temperature

    if (temperature > 30) {
      digitalWrite(LED_PIN, HIGH);  // Turn on LED if temperature > 30°C
    } else {
      digitalWrite(LED_PIN, LOW);   // Turn off LED if temperature <= 30°C
    }
  }

  delay(interval);  // Wait for the next cycle
}
```

#### Summary

* **WiFi connection** is initialized to receive sensor data.
* **LED control** is based on the temperature threshold.
* The system loops every 7 seconds, receiving and processing data.