IoT: Interacting with Arduino & Adafruit IoT Cloud

In this tutorial, we will see how to send the values of temperature, humidity, atmospheric pressure and light intensity read by the sensors on the MKR ENV Shield to the Arduino IoT Cloud and the Adafruit IoT Cloud.

On the other hand, we will also see how to display the message “ON” (in green) and “OFF” (in red) in the MKR RGB Shield depending on the state of a button of type “ON / OFF” (with which we will interact ) created from the Arduino IoT Cloud and from the Adafruit IoT Cloud.

#include <ArduinoJson.h>

////////////////////////////////
#include <ArduinoGraphics.h> // Arduino_MKRRGB depends on ArduinoGraphics
#include <Arduino_MKRRGB.h>

/////////////////////////
#include <WiFiNINA.h>
#include “arduino_secrets.h”

char ssid[] = SECRET_SSID; // your network SSID (name)
char pass[] = SECRET_PASS; // your network password (use for WPA, or use as key for WEP)
int status = WL_IDLE_STATUS;
char server[] = “io.adafruit.com”; // name address for Adafruit IOT Cloud

///////////////////////////

// Initialize the client library
WiFiClient client;

int state = 2;

void setup() {

Serial.begin(9600);
//while (!Serial); // wait for serial port to connect. Needed for native USB port only

// initialize the display
MATRIX.begin();

// set the brightness, supported values are 0–255
MATRIX.brightness(200);

// configure the text scroll speed
MATRIX.textScrollSpeed(125);

MATRIX.clear();
MATRIX.endDraw();

ConectToWIFI();

}

void loop() {

httpRequest();
if (state == 1)
{
MATRIX.clear();
MATRIX.endDraw();
MATRIX.beginText(0, 0, 0, 127, 0); // X, Y, then R, G, B
MATRIX.print(“ ON”);
MATRIX.endText(SCROLL_LEFT);

}else if (state == 0)
{
MATRIX.clear();
MATRIX.endDraw();
MATRIX.beginText(0, 0, 127, 0, 0); // X, Y, then R, G, B
MATRIX.print(“ OFF”);
MATRIX.endText(SCROLL_LEFT);
}else
{
MATRIX.clear();
MATRIX.endDraw();
}

Serial.println(state);

}

// this method makes a HTTP connection to the server:
void httpRequest()
{

// JSon

/*
* GET: /api/v2/{username}/feeds/{feed_key}/data/last
{
“id”: “string”,
“value”: “string”,
“feed_id”: 0,
“group_id”: 0,
“expiration”: “string”,
“lat”: 0,
“lon”: 0,
“ele”: 0,
“completed_at”: “string”,
“created_at”: “string”,
“updated_at”: “string”,
“created_epoch”: 0
}
*/

// close any connection before send a new request.
// This will free the socket on the Nina module
client.stop();

Serial.println(“\nStarting connection to server…”);
if (client.connect(server, 80))
{

Serial.println(“connected to server”);
// Make a HTTP request:
client.println(“GET /api/v2/” IO_USERNAME “/feeds/on-off/data/last HTTP/1.1”);

client.println(“Host: io.adafruit.com”);
client.println(“Connection: close”);
client.println(“Content-Type: application/json”);
client.println(“X-AIO-Key: “ IO_KEY);

// Terminate headers with a blank line
if (client.println() == 0) {
Serial.println(F(“Failed to send request”));
return;
}

// Check HTTP status
char status[32] = {0};
client.readBytesUntil(‘\r’, status, sizeof(status));
if (strcmp(status, “HTTP/1.1 200 OK”) != 0) {
Serial.print(F(“Unexpected response: “));
Serial.println(status);
return;
}

// Skip HTTP headers
char endOfHeaders[] = “\r\n\r\n”;
if (!client.find(endOfHeaders)) {
Serial.println(F(“Invalid response1”));
return;
}

// Skip Adafruit headers
char endOfHeaders2[] = “\r”;
if (!client.find(endOfHeaders2)) {
Serial.println(F(“Invalid response2”));
return;
}

//Deserialize JSon
const size_t capacity = JSON_OBJECT_SIZE(12) + 170;
StaticJsonDocument<capacity> doc;

DeserializationError error = deserializeJson(doc, client);
if (error) {
Serial.print(F(“deserializeJson() failed: “));
Serial.println(error.c_str());
return;
}

const char* value = doc[“value”];

Serial.print(“get data!:”);
Serial.println(value);

if (strcmp(value, “ON”) == 0)
state = 1;
else if (strcmp(value, “OFF”) == 0)
state = 0;
else
state = 2;


} else {
// if you couldn’t make a connection:
Serial.println(“connection failed”);
state = 2;
}

}

void ConectToWIFI()
{
// check for the WiFi module:
if (WiFi.status() == WL_NO_MODULE) {
Serial.println(“Communication with WiFi module failed!”);
// don’t continue
while (true);
}

String fv = WiFi.firmwareVersion();
if (fv < “1.0.0”) {
Serial.println(“Please upgrade the firmware”);
}

// attempt to connect to Wifi network:
while (status != WL_CONNECTED) {
Serial.print(“Attempting to connect to SSID: “);
Serial.println(ssid);
// Connect to WPA/WPA2 network. Change this line if using open or WEP network:
status = WiFi.begin(ssid, pass);

// wait 10 seconds for connection:
delay(10000);
}
Serial.println(“Connected to wifi”);
printWifiStatus();
}

void printWifiStatus() {
// print the SSID of the network you’re attached to:
Serial.print(“SSID: “);
Serial.println(WiFi.SSID());

// print your board’s IP address:
IPAddress ip = WiFi.localIP();
Serial.print(“IP Address: “);
Serial.println(ip);

// print the received signal strength:
long rssi = WiFi.RSSI();
Serial.print(“signal strength (RSSI):”);
Serial.print(rssi);
Serial.println(“ dBm”);