Flashing certificates to MKR.md

Flashing new certificates to an Arduino MKR

For the Arduino MKR to connect to https web servers, it needs to have the relevant certificates installed on it.

Step 1

Connect yout Arduino to your computer and use the latest downloaded version of Arduino Creator from https://www.arduino.cc/en/software

Step 2

Test your Arduino connection is working by running the blink sketch. Remember to change the timing in case the Arduino is already flashed with blink.

// the setup function runs once when you press reset or power the board
void setup() {
  // initialize digital pin LED_BUILTIN as an output.
  pinMode(LED_BUILTIN, OUTPUT);
}

// the loop function runs over and over again forever
void loop() {
  digitalWrite(LED_BUILTIN, HIGH);   // turn the LED on (HIGH is the voltage level)
  delay(2000);                       // wait for a second
  digitalWrite(LED_BUILTIN, LOW);    // turn the LED off by making the voltage LOW
  delay(1000);                       // wait for a second
}

Step 3

Load the Firmware updater from the Tools menu. The example shows the menu on a Mac for a MKR 1010, Windows (and the MKR 1000) should be very similar.

Select the board in the list and click to open the Updater sketch.

Step 4

Upload the updater sketch to your Arduino.

Test the connection to ensure everything is working.

Step 5

Click on add a domain and enter the domain and port needed. If you are following the Arm book it will be google.com:443

Click to upload the certificates to the Arduino.

Step 6

Create a sketch to test it has worked.

Select to manage libraries from the sketch menu.

Search for the ArduinoHTTPLibrary and click to install it.

Use the following code and upload to your Arduino to check the connection works.

#include <ArduinoHttpClient.h> //Handles connection to Google sheet file
#include <WiFiNINA.h> #wifi1010 //MKR1010


int status = WL_IDLE_STATUS;

const char WEBSITE[] = "www.google.com";
const int SSLPORT = 443;
const char* MY_SSID = "GDog";
const char* MY_PWD = "AnnaDillon69^^";
bool flag = false;

WiFiSSLClient wifi; //Wifi connection
HttpClient client = HttpClient(wifi, WEBSITE, SSLPORT); //SSL client

void setup(void) {
    //Initialise serial monitor
    Serial.begin(9600);
    while (!Serial);
    
   //Check if WiFi possible (shouldn't be a problem if you have MKR1000 or 1010)
   if (WiFi.status() == WL_NO_SHIELD) {
    Serial.println("WiFi device not present");
    //while (true);     // don't continue:
  }

  //Connect to WiFi
  while ( status != WL_CONNECTED) {
    Serial.print("Attempting to connect to Network named: ");
    Serial.println(MY_SSID);

    // Connect to WPA/WPA2 network:
    status = WiFi.begin(MY_SSID, MY_PWD);
  }
  Serial.println("Connected to wifi");
  printWifiStatus();
}

void loop(void) {
  if (!flag) {
    Serial.println("\nSending Data to Server..."); 
    String URL = (String) "/";
    client.get(URL); //call the web file
    int statusCode = client.responseStatusCode(); //Get the response code
    Serial.print("Status code: "); 
    Serial.println(statusCode);
    if (statusCode == 302 or statusCode == 301) { //Response code 301/302 means redirect
      while(client.headerAvailable()) //Go through headers
      {
        String headerName = client.readHeaderName();
        String headerValue = client.readHeaderValue();
        Serial.println(headerName);
        Serial.println(headerValue);
      }
    } else {
      if (statusCode == 200) {
        flag = true;
        Serial.println("All fine!");
      }
    }
  }
  delay(10000); //Wait 10s before resending
}

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

  // print your WiFi shield'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");
}