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DFRobot - 4 Relay Shield for Arduino

Let's test this shield.

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本项目中用到的东西

 

Hardware components

HARDWARE LIST
1 DFRobot - 4 Channel Relay Shield for Arduin
1 Arduino UNO
1 Digilent 60W PCIe 12V 5A Power Supply

Software apps and online services

Arduino IDE

Story

 

With a relay circuits can be switched with a different voltage than is necessary for the operation of the Arduino. And how easy it can be with a matching shield for the Arduino, you'll learn here.

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When I put the Relay Shield on an Arduino Uno for the first time, I first had to smile for myself: there were actually two PINs on each side too many.

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This can certainly be explained with the compatibility with other Arduino boards, but a mega is just not available to me. The product page also lists no special boards and so I find the note "Compatible with Arduino UNO Rev3" a bit poor.

No matter - for a first test with my room fountain to switch a 4 colored LED via 12V I do not need these PINs. We focus on using one of the relays.

The default assignment for addressing the 4 relays can be easily changed via jumper. This is also not necessary here and so we start with D2, D7, D8 and D10.

The shield has 4 buttons (S1-S4), so that a connection test is also possible without uploaded sketch.

With the help of Power DC adapters, I have connected a Y-cable to both the Arduino and Relay1. In my setup I use the green terminal adapters COM1 and NO1, respectively the plus pole. This means that I use the relay like a light switch and then turn on my 4 LEDs when the circuit is closed.

 

COM1 and NO1 = Plus

 

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CODE
#define relay1 2
#define relay2 7
#define relay3 8
#define relay4 10
void setup() {
Serial.begin(9600);// setup Serial Monitor to display information
pinMode(relay1, OUTPUT);// connected to Relay 1
pinMode(relay2, OUTPUT);// connected to Relay 2
pinMode(relay3, OUTPUT);// connected to Relay 3
pinMode(relay4, OUTPUT);// connected to Relay 4
}
void loop() {
digitalWrite(relay1,HIGH);// turn relay 1 ON
Serial.println(" Relay 1 ON");
delay(3000);// keep in relay 1 On for 3 seconds
digitalWrite(relay1, LOW);// turn relay 1 OFF
Serial.println(" Relay 1 OFF");
delay(3000);// keep in relay 1 OFF for 3 seconds
}

With this "Hello World"-example I turn the Relay1 on Default D2 for 3 seconds on and off.

The example sketch offered for download on the product page is much more modern: Here, the Serial Monitor can be accessed by setting the digits 1-4 to the individual relays with a setting of 57, 600 baud.

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Appropriately, you will find in the sketch the via "case" command possible reaction to it.

CODE
case '1':                         
        Serial.println("Relay1");
        val=digitalRead(relayPin[0]);
        val=!val;
        digitalWrite(relayPin[0],val);
        break;

With this we quickly approach the question, can the shield also be controlled via radio? The shield has room to hold an XBee device.

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Unfortunately, in my case, Digi's configuration software - the XCTU - has not been able to detect my two devices - Pro S2B and Pro S1. If someone wants to help me - feel welcome!

CODE
/*
 # This Sample code is for testing the Relay shield V2.1 for Arduino.
  
 # Editor : Phoebe
 # Date   : 2013.2.28
 # Ver    : 0.1
 # Product: Relay shield for Arduino
 # SKU    : DRI0144
   
 # Hardwares:
 1. Arduino UNO
 2. Relay Shield For Arduino V2.1 
 3  Power Supply:7~ 12V
 */

byte relayPin[4] = {
  2,7,8,10};
//D2 -> RELAY1
//D7 -> RELAY2
//D8 -> RELAY3
//D10 -> RELAY
char input=0;
int val;

void setup() {
  for(int i = 0; i < 4; i++)  pinMode(relayPin[i],OUTPUT);
  Serial.begin(57600); 
  delay(100); 
  Serial.println("Press 1-4 to control the state of the relay");
  Serial.println("waiting for input:");
  for(int j = 0; j < 4; j++)  digitalWrite(relayPin[j],LOW);
}

void loop() {
  if (Serial.available()) 
  {  
    char input= Serial.read();  
    if(input != -1)
    {
      switch(input)
      {
   
      case '1':                         
        Serial.println("Relay1");
        val=digitalRead(relayPin[0]);
        val=!val;
        digitalWrite(relayPin[0],val);
        break;
      case '2':
        Serial.println("Relay2");
        val=digitalRead(relayPin[1]);
        val=!val;
        digitalWrite(relayPin[1],val);
        break;
      case '3':
        Serial.println("Relay3");
        val=digitalRead(relayPin[2]);
        val=!val;
        digitalWrite(relayPin[2],val);
        break;
      case '4':
        Serial.println("Relay4");
        val=digitalRead(relayPin[3]);
        val=!val;
        digitalWrite(relayPin[3],val);
        break;    
        
      default:
        if(input != '\r' && input != '\n')
         Serial.println("invalid entry");
        break;
      }
    }
//    else unablerelay();
  }
}

The article was first published in hackster, November 3, 2019

cr: https://www.hackster.io/ingo-lohs/dfrobot-4-relay-shield-for-arduino-9a56bd

author: Ingo Lohs

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