Basic IoT scenario using HCP – Part 2 – Setup Particle Photon for receiving data

During this exercise we’ll use the following items:

• Particle Photon on breadboard
• USB cable
• Some wires
• 8 x 8 matrix display (max7219)
• Relayboard

Setup the relayboard with its pins connected in the following way:

• VCC connected to 3V3 on the Photon
• GND connected to GND on the Photon
• Channel connected to D0 on the Photon

Setup the matrix display with its pins connected in the following way:

• VCC connected to 3V3 on the Photon
• GND connected to GND on the Photon
• DIN connected to A2 on the Photon
• CS connected to A4 on the Photon
• CLK connected to A3 on the Photon

Login into the particle cloud

Go to: http://build.particle.io

Select the “Code” option at the bottom left of

the screen and create a new app. Just like we did in part 1 of the serie.

Select the “Libraries” button on the bottom left and search for the “MAX7219”

// This #include statement was automatically added by the Particle IDE.

#include “LedControl-MAX7219-MAX7221/LedControl-MAX7219-MAX7221.h”

LedControl *led;

int led1 = D0; //or D7 if you don’t use the relayboard

int phase = 0;

char message[64];

char custMessage[64];

int messageLength = 0;

int myUptime = 0;

uint8_t data = A2;

uint8_t load = A4;

uint8_t myclock = A3;

void setup() {

led = new LedControl(data,myclock,load,1); //DIN,CLK,CS,HowManyDisplays

led->shutdown(0,false); //Turn it on

led->setIntensity(0,1);

Spark.function(“SetMessage”, setMessage);

Spark.variable(“Message”, custMessage, STRING);

pinMode(led1, OUTPUT);

Particle.function(“led”,ledToggle);

digitalWrite(led1, LOW);   

}

void loop() {

if(phase==0){ //Message-loop starts

        if(strlen(custMessage) == 0)

        {

            myUptime = (int)(millis()/1000);

            sprintf(message,”#SAPInsideTrack”); //update message

        }

        else

        {

            strcpy(message, custMessage); //update message

        }

        messageLength = strlen(message); // …and length

        led->tweenLetters(0,’ ‘,message[phase]); //scroll from empty to 1 letter

}

if(phase<messageLength-1){ //next characters except last one

led->tweenLetters(0,message[phase],message[phase+1]);

        phase++;

}else if(phase==messageLength-1){//last character scrolls to empty

        led->tweenLetters(0,message[phase],’ ‘);

        phase = 0; //restart message-loop

}

}

int setMessage(String _message)

{

_message.toCharArray(custMessage, 64);

return 0;

}

int ledToggle(String command) {

if (command==”on”) {

        digitalWrite(led1,HIGH);

        return 1;

}

else if (command==”off”) {

        digitalWrite(led1,LOW);

        return 0;

}

else {

        return -1;

}

  }