Need help with wireless project

Projects General Guidance
21

It says something about a mirf library but I'm not sure what that means...

22

I've tried changing the wires around and I can't get the nrf24l01 to work. Should I just try using something else?

23

Actually I just thought of something- since I only need each arduino to transmit a sound to a speaker wirelessly, could I just take apart a bluetooth headset (like for a phone) and use that?

24

Post what you have so far using the # code icon.

You should start out by breaking the project down into smaller steps. For example:

Check your hardware setup by making sure you can talk to the rf module and read a couple of registers:

#include <SPI.h>
#include <Mirf.h>
#include <nRF24L01.h>
#include <MirfHardwareSpiDriver.h>

Nrf24l rf = Nrf24l(8, 7, 80, 32);

void setup() 
{   
    uint8_t value = 0;
    
    Serial.begin(115200);
    Serial.println( "Starting wireless..." );
    
    // Setup
    rf.spi = &MirfHardwareSpi;
    rf.init();
    rf.setRADDR((byte *)"ard01");
    rf.setTADDR((byte *)"ard02");
    rf.config();
    
    rf.readRegister( RF_SETUP, &value, sizeof(value) );
    Serial.print( "rf_setup = 0x" );
    Serial.println( value, HEX );
    
    rf.readRegister( SETUP_RETR, &value, sizeof(value) );
    Serial.print( "setup_retr = 0x" );
    Serial.println( value, HEX );
    
    Serial.println( "Wireless initialized!" );
}

void loop() {}

Check the values of the registers against what the datasheet says are the defaults and make sure they match. If they're 0x00 or 0xFF then there's something wrong with the hardware connection.

Once you have that working, try sending a message between the two arduinos.

void setup()
{
     ... same setup as before plus:

    /* turn on auto-ack feature for more reliable communication */
    value = 0x3f;
    rf.writeRegister(EN_AA, &value, sizeof(value));     // enable auto-ack
    value = 0x4f;
    rf.writeRegister(SETUP_RETR, &value, sizeof(value)); // 15 retransmits, 1msec timeout

}

uint32_t lastSent = 0;

void loop()
{
    /* Send a message every 5 seconds */
    if ((millis() - lastSent) > 5000) {
       uint8_t buf[32];
       strncpy("Hello!\n", (char *)buf, sizeof(buf));
       rf.send(buf);
       lastSent = millis();
    }

    /* Check for incoming messages */
    if (!rf.isSending() && rf.dataReady()) {
        char msg[32];
        rf.getData((uint8_t *)&msg);
        msg[31] = '\0'; // null terminate it just in case
        Serial.print("Received message: ");
        Serial.print(msg);
    }
}

Once you have that working you can start on your project.