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Blynk, Arduino and 433 MHz RF

Hello everyone, sorry for my english …

Please can someone help me with Blynk, Arduino Mega and 433 MHz transmitter?

I would like to use Arduino Mega with transmitter to send the codes in RF 433 Mhz and some Arduino Nano with 433 MHz RF receiver that, according to the code received, turn on and off the relays …

Can someone help me with Blynk?

Thanks so much.

you need to be a bit more specific than that:

  • What do you have already coded (pls share)?
  • With what do you exactly need help?
  • What is the blynk part of your project?
1 Like

Thanks for your interest…

I can not create the part that sends the codes … for example:

If I send the code 1755 it turns on the light of the room 1

if I send the code 1756 it turns off the light of the room 1

if I send the code 1888 the boiler is turned on

if I send the code 1889 the boiler is turned off …

thank you.

/*************** 433Mhz Settings ***************/
#include <RCSwitch.h>
RCSwitch mySwitch = RCSwitch();

#define PACKET_LENGTH 24 //length

#define SWITCH_1_ON   1755 // decimal code
#define SWITCH_1_OFF  1756 

#define SWITCH_2_ON   1888 
#define SWITCH_2_OFF  1889 

int BTN1;
int BTN2;

....

BLYNK_WRITE(V1) {
  BTN1 = param.asInt();
  if (BTN1 == true) {
     mySwitch.send(SWITCH_1_ON, PACKET_LENGTH);
     }
  else {
      mySwitch.send(SWITCH_1_OFF, PACKET_LENGTH);
   }
}

BLYNK_WRITE(V2) {
  BTN2 = param.asInt();
  if (BTN2 == true) {
       mySwitch.send(SWITCH_2_ON, PACKET_LENGTH);
     }
  else {
      mySwitch.send(SWITCH_2_OFF, PACKET_LENGTH);
    }
}

Thanks Alexis, great …

Now I have two arduino nano, the first controls the light of camera 1 and the second commands the caladia, both have a 433 MHz RF receiver, according to the code launched by the transmitter they must be able to reset the digital pin 2 or 3 … .

Thank you

1 Like

thank you very much for the help you gave me …

But how do I make Arduino and Blynk understand that the 433MHz RF is connected to the digital 4 pin?

Thank you

hello !
this is the code :slight_smile:

/*      ARDUINO  NODEMCU
            0       D3
            1       D10
            2       D4
            3       D9
            4       D2
            5       D1
           12       D6
           13       D7
           14       D5
           15       D8
           16       DO */

 mySwitch.enableTransmit(4); //nodemcu D2

Thanks, it gives me error "exit status 1 ‘mySwitch’ does not name a type

What does it mean?

don’t forget to declare that

#include <RCSwitch.h>
RCSwitch mySwitch = RCSwitch();

I declared it
but still gives me the error …

Help me, please …

please post your entire code, I will take a look.
don’t forget to format it.

‘RCSwitch’ does not name a type
RCSwitch mySwitch = RCSwitch();
^
error: ‘mySwitch’ was not declared in this scope

this is the issue when I comment :

 //#include <RCSwitch.h>

so, you have not the RCSwitch.h library , or you made a mistake naming your lib

#define BLYNK_PRINT Serial


#include <SPI.h>
#include <Ethernet.h>
#include <BlynkSimpleEthernet.h>
#include <DHT.h>
#include <RCSwitch.h>


RCSwitch mySwitch = RCSwitch();



#define PACKET_LENGTH 24 //length

#define SWITCH_1_ON   1173 // decimal code
#define SWITCH_1_OFF  1179 

#define SWITCH_2_ON   1273 
#define SWITCH_2_OFF  1279 

#define SWITCH_3_ON   1373 // decimal code
#define SWITCH_3_OFF  1379 

#define SWITCH_4_ON   1473 
#define SWITCH_4_OFF  1479 

#define SWITCH_5_ON   1573 // decimal code
#define SWITCH_5_OFF  1579 

#define SWITCH_6_ON   1673 
#define SWITCH_6_OFF  1679 

int BTN1;
int BTN2;
int BTN3;
int BTN4;
int BTN5;
int BTN6;


// You should get Auth Token in the Blynk App.
// Go to the Project Settings (nut icon).
char auth[] = "token";

#define W5100_CS  10
#define SDCARD_CS 4

#define DHT1PIN 2          // What digital pin we're connected to
#define DHT2PIN 3          // What digital pin we're connected to

// Uncomment whatever type you're using!
#define DHT1TYPE DHT11     // DHT 11
#define DHT2TYPE DHT11   // DHT 22, AM2302, AM2321
//#define DHTTYPE DHT21   // DHT 21, AM2301

DHT dht1(DHT1PIN, DHT1TYPE);
DHT dht2(DHT2PIN, DHT2TYPE);
BlynkTimer timer;

// This function sends Arduino's up time every second to Virtual Pin (5).
// In the app, Widget's reading frequency should be set to PUSH. This means
// that you define how often to send data to Blynk App.
void sendSensor()
{
  float h1 = dht1.readHumidity();
  float t1 = dht1.readTemperature(); // or dht.readTemperature(true) for Fahrenheit

  float h2 = dht2.readHumidity();
  float t2 = dht2.readTemperature(); // or dht.readTemperature(true) for Fahrenheit

  if (isnan(h1) || isnan(t1)) {
    Serial.println("Failed to read from DHT sensor!");
    return;
  }

   if (isnan(h2) || isnan(t2)) {
    Serial.println("Failed to read from DHT sensor!");
    return;
  }
  // You can send any value at any time.
  // Please don't send more that 10 values per second.
  Blynk.virtualWrite(V5, h1);
  Blynk.virtualWrite(V6, t1);

    Blynk.virtualWrite(V7, h2);
    Blynk.virtualWrite(V8, t2);
}

void setup()
{
  // Debug console
  Serial.begin(9600);

  pinMode(SDCARD_CS, OUTPUT);
  digitalWrite(SDCARD_CS, HIGH); // Deselect the SD card

  Blynk.begin(auth);
  // You can also specify server:
  //Blynk.begin(auth, "blynk-cloud.com", 8442);
  //Blynk.begin(auth, IPAddress(192,168,1,100), 8442);

  dht1.begin();
  dht2.begin();

  // Setup a function to be called every second
  timer.setInterval(1000L, sendSensor);
}



BLYNK_WRITE(V11) {
  BTN1 = param.asInt();
  if (BTN1 == true) {
     mySwitch.send(SWITCH_1_ON, PACKET_LENGTH);
     }
  else {
      mySwitch.send(SWITCH_1_OFF, PACKET_LENGTH);
   }
}

BLYNK_WRITE(V12) {
  BTN2 = param.asInt();
  if (BTN2 == true) {
       mySwitch.send(SWITCH_2_ON, PACKET_LENGTH);
     }
  else {
      mySwitch.send(SWITCH_2_OFF, PACKET_LENGTH);
    }
}

BLYNK_WRITE(V13) {
  BTN3 = param.asInt();
  if (BTN3 == true) {
     mySwitch.send(SWITCH_1_ON, PACKET_LENGTH);
     }
  else {
      mySwitch.send(SWITCH_1_OFF, PACKET_LENGTH);
   }
}

BLYNK_WRITE(V14) {
  BTN4 = param.asInt();
  if (BTN4 == true) {
       mySwitch.send(SWITCH_2_ON, PACKET_LENGTH);
     }
  else {
      mySwitch.send(SWITCH_2_OFF, PACKET_LENGTH);
    }
}

BLYNK_WRITE(V15) {
  BTN5 = param.asInt();
  if (BTN5 == true) {
     mySwitch.send(SWITCH_1_ON, PACKET_LENGTH);
     }
  else {
      mySwitch.send(SWITCH_1_OFF, PACKET_LENGTH);
   }
}

BLYNK_WRITE(V26) {
  BTN6 = param.asInt();
  if (BTN6 == true) {
       mySwitch.send(SWITCH_2_ON, PACKET_LENGTH);
     }
  else {
      mySwitch.send(SWITCH_2_OFF, PACKET_LENGTH);
    }
}

void loop()
{
  Blynk.run();
  timer.run();
}

…and he forgot anyhow :stuck_out_tongue:

@nervimarco Please read the proper way to post code here…

:joy::joy::joy::joy::joy::joy:

@nervimarco

I compiled your code and it works fine :wink:
so you probably have an issue with one of the libraries !

can you send me error list?

Thank you so much for your support …

the error comes out when I insert the line
“mySwitch.enableTransmit (4);”

gives me error “exit status 1 ‘mySwitch’ does not name a type”

I do not understand.

Thank you

ah ah
you put an extra space !
try enableTransmit(4);
:wink:

thanks, I’ve already tried …
nothing changes, always a mistake …

Help…

are you sure you put mySwitch.enableTransmit(4); at the right place?
it must be into the void setup , like this

void setup()
{
  // Debug console
  Serial.begin(9600);
  mySwitch.enableTransmit(4); //<<<<<<<<<<<<<--------------------
  pinMode(SDCARD_CS, OUTPUT);
  digitalWrite(SDCARD_CS, HIGH); // Deselect the SD card
1 Like