433MHz Receiver Weird Junk

Projects Programming
1

Hello,

can onyone tell me why am I seeing this junk at the end of received message?(Please find attached) How can I remove it?
I'm using Visual Studio Code with PlatformIO extension.
Here is my code:

MainTransmitter:

#include <Arduino.h>
#include "433MHzRFTransmitter.h"

void setup() {
  RFTransmitterInitialization();
}

void loop() {
  RFTransmitterSendMessage(1000);
}

433MHzRFTransmitter.h:

/*
Library used to send and receive unaddressed, 
unreliable datagrams via RF modules using Amplitude Shift Keying
*/
#include "RH_ASK.h"
//Library used by RH_ASK, need to be included
#include "SPI.h"
//Creating driver object4
extern RH_ASK rf_driver;
//Time interval between sending message - needed to use millis() instead delay()
extern int transmitterSendingInterval;
//Variable needed to store millis() 
extern unsigned long previousTransmitterMillis;

//RF driver initialization
void RFTransmitterInitialization();
/*
Sending message via RF module using send function from RH_ASK library.
@Param - time interval between sending message
*/
void RFTransmitterSendMessage(int sendingTimeInterval);

433MHzRFTransmitter.cpp:

#include "433MHzRFTransmitter.h"
RH_ASK rf_driver;
int transmitterSendingInterval = 1000;
unsigned long previousTransmitterMillis = 0;

void RFTransmitterInitialization() {
    rf_driver.init();
}

void RFTransmitterSendMessage(int sendingTimeInterval) {
    transmitterSendingInterval = sendingTimeInterval;
    if(millis() - previousTransmitterMillis >= transmitterSendingInterval) {
        const char *msg = "Hello Raadley!";

        rf_driver.send((uint8_t *)msg, strlen(msg));
        rf_driver.waitPacketSent();

        previousTransmitterMillis = millis();
    }
}

MainReceiver:

#include <Arduino.h>
#include "433MHzRFReceiver.h"

void setup() {
  RFReceiverInitialization();
  Serial.begin(9600);
}

void loop() {
  RFReceiverReadMessage();
}

433MHzRFReceiver.h:

#include "RH_ASK.h"
#include "SPI.h"

extern RH_ASK rf_driver;

void RFReceiverInitialization();
//Reads message using Send function from RH_ASK library and prints it in console
void RFReceiverReadMessage();

433MHzRFReceiver.cpp:

#include "433MHzRFReceiver.h"

RH_ASK rf_driver;

void RFReceiverInitialization() {
    rf_driver.init();
    //Serial.begin(9600);
}

void RFReceiverReadMessage() {
    uint8_t buf[14];
    uint8_t buflen = sizeof(buf);

    if(rf_driver.recv(buf, &buflen)) {
        Serial.print("Message received: ");
        Serial.println((char *)buf);       
    }
}

I would be grateful if anyone could help me.
Thank you in advance.

Przechwytywanie.PNG

2

What's the problem?
Did you forget to terminate the receive buffer?

3

I'm not sure what do you mean. I've done everything the same as it is in this tutorial: Using 433MHz RF Modules with Arduino | DroneBot Workshop
I just want to know why there is some additional text at the end? What it is, and how can I get rid of it?
Thank you in advance.

4 
if(rf_driver.recv(buf, &buflen)) {
        buf [buflen] = '\0';
        Serial.print("Message received: ");
        Serial.println((char *)buf);

And now?

(You may wish to bounds check "buflen", but let's see how this goes for now)

5

Now it works as I wanted. Now I need to read more about it. If I my ask could you please show me how to check this "buflen"(What do you mean?)? Anyway I'm really satisfied that my mystery has been solved.
Thank you so much.