Published April 2, 2017 © GPL3+

Control a Lamp with MKR Relay Proto Shield

Set an alarm with MKR1000 and MKR Relay Proto Shield to turn a lamp on/off.

IntermediateFull instructions provided4,323

Control a Lamp with MKR Relay Proto Shield

Things used in this project

Hardware components

Arduino MKR Relay Proto Shield

Arduino MKR1000

Desktop Lamp

Hand tools and fabrication machines

Adafruit Wire Strippers

Adafruit Pocket Screwdriver

Adafruit Digital Multimeter

Story

***Please use caution on this project, you will be working with 120 volts AC!***

Using the MKR Relay Shield and the MKR1000 control a desktop lamp. This project is an extension of the MKR Relay Shield tutorial provided by Arduino.

MK1000 & MKR Relay Shield

First gather all necessary equipment and supplies.

Identify the Hot wire on your lamp, MAKE SURE LAMP IS UNPLUGGED! Examine your cord, one side will have a ribs, the other side will not. The side without (or smooth side) is your Hot wire. See Figure 2

Figure 2

With the Hot wire identified, cut and strip about 1/4in, leaving wire exposed.

With Hot wire ready, connect to MKR Relay Shield (Figure 3). The Hot wire coming from the plug will connect to "COM".

The Hot wire going to lamp will connect to "NO". Nothing will be connected to "NC".

Figure 3 (Red tape wire is going to lamp)

With MKR1000 powered on, plug in desktop lamp, the lamp should be off at this stage. Upload the code to your MKR1000 and set the time using the following tutorial, Scheduled Relays

***Differences in the Arduino IDE from the tutorial***

Update your network name and password

Change the timezone to match yours (Default is GMT)

Set alarm, default is 5 minutes

Lamp On/Off with MKR Relay Shield

/*
  WiFi Web Server to set an alarm on the RTC to drive a relay

  A simple web server that shows a form to insert an alarm time
  on a MKR1000 + MKR Relay Shield to drive relays on MKR Relay Shield.
  
  At alarm match the two outputs will be driven HIGH for 5 minutes

  Circuit:
   - MKR1000 + MKR Relay Proto Shield Shield

  created 05 Feb 2017
  by Arturo Guadalupi
*/

#include <SPI.h>
#include <WiFi101.h>
#include <RTCZero.h>

char ssid[] = "yournetwork";      // your network SSID (name)
char pass[] = "yourpassword";     // your network password
int keyIndex = 0;                 // your network key Index number (needed only for WEP)

int status = WL_IDLE_STATUS;

WiFiServer server(80);

const int relay1 = 1;
const int relay2 = 2;
const int onMinutes = 5; //stay on for 5 minutes, update with length required

RTCZero rtc; // create an RTC object

const int GMT = -7; //change this to adapt it to your time zone //(Changed to PST, update number only)

bool driveOutputs = false;

void setup() {
  //initialize relays pins and drive them low
  pinMode(relay1, OUTPUT);
  pinMode(relay2, OUTPUT);
  digitalWrite(relay1, LOW);
  digitalWrite(relay2, LOW);

  Serial.begin(9600);  //initialize serial communication

  // check for the presence of the shield:
  if (WiFi.status() == WL_NO_SHIELD) {
    Serial.println("WiFi shield not present");
    // don't continue:
    while (true);
  }

  // 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);
  }
  server.begin();  // initialize the server
  printWiFiStatus(); // you're connected now, so print out the status:

  rtc.begin(); // initialize the RTC library
  setRTCwithNTP(); // set the RTC time/date using epoch from NTP
  printTime(); // print the current time
  printDate(); // print the current date
  rtc.attachInterrupt(alarmMatch); // call alarmMatch() function when interrupt occur
}

void loop() {
  WiFiClient client = server.available();

  if (client) {
    String request = client.readStringUntil('\n');  // receive the request
    request.trim();

    if ((request == "GET / HTTP/1.1") || (request == "GET /post_time?usr_time= HTTP/1.1")) {
      // show the selection time page
      client.println("HTTP/1.1 200 OK");
      client.println("Content-Type: text/html");
      client.println("Connection: close");
      client.println();
      client.println("<!DOCTYPE HTML>");
      client.println("<html>");
      client.println("<body>");
      client.println("<p><strong>MKR Relay Proto Shield control page</strong></p>");
      client.println("<form action=\"post_time\">");
      client.println("Select a time to turn relays ON at:");
      client.println("<input type=\"time\" name=\"usr_time\">");
      client.println("<input type=\"submit\">");
      client.println("</form>");
      client.println("</body>");
      client.println("</html>");
      client.stop();
    }

    else {
      bool requestFound = false;  // flag used to check if the request has been received
      //search for the sent time
      for (int hours = 0; (hours < 24) && (requestFound == false); hours++) { // stop the for if request is found
        for (int minutes = 0; (minutes < 60) && (requestFound == false); minutes++) { // stop the for if request is found
          String requestString = "GET /post_time?usr_time=";  // fixed request part
          // add a zero if number 
          if (hours < 10) {
            requestString += "0";
          }

          requestString += hours;
          requestString += "%3A";

          if (minutes < 10) {
            requestString += "0";
          }

          requestString += minutes;
          requestString += " HTTP/1.1";

          if (requestString == request) {
            requestFound = true;
            String timeSet = "<p>Alarm correctly set to ";
            if (hours < 10)
              timeSet += "0";
            timeSet += hours;
            timeSet += ":";
            if (minutes < 10)
              timeSet += "0";
            timeSet += minutes;
            timeSet += "</p>";
            // show the success page
            client.println("HTTP/1.1 200 OK");
            client.println("Content-Type: text/html");
            client.println("Connection: close");  // the connection will be closed after completion of the response
            client.println();
            client.println("<!DOCTYPE HTML>");
            client.println("<html>");
            client.println("<p><strong>Success!</strong></p>");
            client.println(timeSet);
            client.println("</body>");
            client.println("</html>");
            client.stop();

            //reset outputs
            digitalWrite(relay1, LOW);
            digitalWrite(relay2, LOW);
            
            Serial.println();
            Serial.print("Alarm set to: ");
            print2digits(hours);
            Serial.print(":");
            print2digits(minutes);
            Serial.println();
            
            rtc.setAlarmTime(hours, minutes, 00); // set alarm
            rtc.enableAlarm(rtc.MATCH_HHMMSS); // enable the RTC interrupt to match hours, minutes and seconds
          }
        }
      }

      if (requestFound == false) {
        //flush the client
        while (client.available()) {
          client.read();
        }

        // print the not found error code
        client.print("HTTP/1.1 ");
        client.print(404);
        client.print(" ");
        client.println("Not Found");
        client.println("Connection: close");
        client.println();
        client.stop();
      }
    }
  }
}

void alarmMatch() {
  //togle the drive output value
  Serial.println("Alarm match!");
  if (driveOutputs == false) {
    driveOutputs = true;
    digitalWrite(relay1, HIGH);
    digitalWrite(relay2, HIGH);
    
    // set next alarm in 5 minutes to drive outputs HIGH for this time
    int thisMinutes = rtc.getMinutes() + onMinutes;
    if (onMinutes >= 60) {
      rtc.setAlarmTime(rtc.getHours() + 1, thisMinutes - 60, 00);
    }
    else {
      rtc.setAlarmTime(rtc.getHours(), thisMinutes, 00);
    }
  }
  else {
    driveOutputs = false;
    digitalWrite(relay1, LOW);
    digitalWrite(relay2, LOW);
  }
}

void setRTCwithNTP() {
  unsigned long epoch;
  int numberOfTries = 0, maxTries = 6;
  do {
    epoch = WiFi.getTime();
    numberOfTries++;
  }
  while ((epoch == 0) || (numberOfTries > maxTries));

  if (numberOfTries > maxTries) {
    Serial.print("NTP unreachable!!");
    while (1);
  }
  else {
    Serial.print("Epoch received: ");
    Serial.println(epoch);
    rtc.setEpoch(epoch);

    Serial.println();
  }
  rtc.setHours(rtc.getHours() + GMT);
}

void printTime() {
  print2digits(rtc.getHours());
  Serial.print(":");
  print2digits(rtc.getMinutes());
  Serial.print(":");
  print2digits(rtc.getSeconds());
  Serial.println();
}

void printDate() {
  print2digits(rtc.getDay());
  Serial.print("/");
  print2digits(rtc.getMonth());
  Serial.print("/");
  print2digits(rtc.getYear());

  Serial.print(" ");
}

void print2digits(int number) {
  if (number < 10) {
    Serial.print("0");
  }
  Serial.print(number);
}

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");
}