RF 433mHZ modules not working

Using Arduino Networking, Protocols, and Devices
#1

Hi everyone,
I have 2 Arduinos (one Arduino Nano connected to my PC, and an Arduino pro Mini which will receive the data through RF)
I bought a pair of transmitter/receiver 433Mhz, and I’m using Virtualwire libraries. The models are:

  • receiver: RX-XD 5v
  • transmitter: XD-FST (FS1000A)

I’m sending data from hyperterminal to my Arduino Nano, and it lights a led when it receives string “ocho” (ok).
The problem is I can’t make the transmision work!! I attach the code of the rx and tx, and 2 photos of the protoboards with the Arduinos. I hope someone can help! I suspect of the antennas, I tried different lenghts (18 cm, 30 cm, eg), but i’m using small wires, maybe this is a problem? Or using jumper wires can make them not work at all? (I tried bringing them very close and nothing…)

// RX:
    #include <VirtualWire.h>
    
    int pos = 0;
    int ledOcho=3;
    int ledRx=5;
    int ledGrabOK=10;
    int pataRx=8;
    
void setup()
{
    vw_set_ptt_inverted(true);
    vw_setup(2000);       
    vw_set_rx_pin(pataRx);
    vw_rx_start();       
    pinMode(ledOcho, OUTPUT);
    pinMode(ledRx,OUTPUT);
    pinMode(ledGrabOK,OUTPUT);
}


void loop()
{
    byte buf[VW_MAX_MESSAGE_LEN];        
    byte buflen = VW_MAX_MESSAGE_LEN;    
    int i;
    String numeroPedido="";
    digitalWrite(ledGrabOK,HIGH);
   // enters if receives data:
    if( vw_get_message(buf, &buflen) )
    {
        digitalWrite(ledRx,HIGH);
        for (i = 0; i < buflen; i++)
        {
            if ((char)buf[i]=='.'){ break; }
            numeroPedido= numeroPedido +(char)buf[i];
        }
        
        if (numeroPedido=="ocho"){ digitalWrite(ledOcho,HIGH); }
        else{digitalWrite( ledOcho,LOW); }
        numeroPedido="";                                            

        digitalWrite(ledRx,LOW);
    }
}

// TX
#include <VirtualWire.h>

// Variables globales
char cad[100];
int i=0;
String cadena="";
int ledOcho=2;
int pataTx=6;
int answer=0;
int ledTx=10;
void setup()
{
        vw_set_ptt_inverted(true);
        vw_set_tx_pin(pataTx);
	Serial.begin(9600);	// Abre el puerto serie a 9600 bps
	vw_setup(2000);		// Abre el puerto RF a 2000 bps
        pinMode(ledOcho, OUTPUT);
        pinMode(ledTx,OUTPUT);
	Serial.print("Finalice con \".\" cada envio de datos.");
}


void loop()
{
	// Indica cuantos caracteres hay en el buffer:
	if( Serial.available() > 0)
	{
		cad[i] = Serial.read();	
                Serial.print(char(cad[i] ));
                cadena = cadena + cad[i];
		i++;
	}

	
	if( cad[i-1] == '.')
	{
		cad[i] = '\0';						
		i=0;
                if (cadena == "ocho."){
                   digitalWrite(ledOcho, HIGH);
                }
                else{
                  digitalWrite(ledOcho,LOW);
                }
                cadena = "";    
                answer=vw_send((byte *)cad, strlen(cad));	
                digitalWrite(ledTx,answer);
                answer=0;
                vw_wait_tx();
		delay(200);
	}
}

The receiver should light ledRX when vw_get_message(buf, &buflen) get true, but never happens.
I tried not setting: vw_set_ptt_inverted(true); , nothing

Mariana

arduinonano.PNG
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#2 
		cad[i] = Serial.read();	
                Serial.print(char(cad[i] ));
                cadena = cadena + cad[i];

This looks pretty stupid. Use a String (not preferred) or a string (preferred) to store the data, not both.

The serial port on the receiver is doing what? Why is it NOT being used for debugging?

#3

This looks pretty stupid. Use a String (not preferred) or a string (preferred) to store the data, not both.

Ok. Btw, this comment has nothing to do with the RF problem. I’m using String “cadena” to turn on or off a led on the transmitter.

The reciver is the Arduino Pro Mini, and is not connected to USB true, but it also never enters the if( vw_get_message(buf, &buflen) ), as i say in the previous message.

#4