Code error on slave or recever code for transcever NR24L01

Projects Programming
1

/*
14CORE NRF24L01 SLAVE/RECIEVER
*/

#include <SPI.h> //Include SPI Code Library which can be downloaded below
#include "nRF24L01.h" //Include NRF24L01 Code Library which can be downloaded below
#include "RF24.h" //Inlcude NRF24 Code Library which can be downloaded below

int msg[1];
RF24 radio(9,10); // NRF24L01 Pin
const uint64_t pipe = 0xE8E8F0F0E1LL; //Start Pipe Communication Address
int Indicator = 3; //This the LED which is connected to Arduino Pin 3

void setup(void){
Serial.begin(9600);
radio.begin();
radio.openReadingPipe(1,pipe);
radio.startListening();
pinMode(Indicator, OUTPUT);}

void loop(void){
if (radio.available()){
bool done = false;
while (!done){
done = radio.read(msg,1); // ERROR MESSAGE void value not ignored as it ought to be //
Serial.println(msg[0]);
if (msg[0] == 111){delay(10);digitalWrite(Indicator, HIGH);}
else {digitalWrite(Indicator, LOW);}
delay(10);}}
else{Serial.println("Error: No Radio Transmission");}}

Arduino: 1.8.9 (Windows 10), Board: "Arduino/Genuino Mega or Mega 2560, ATmega2560 (Mega 2560)"

C:\Users\BILL\Documents\Arduino\sketch_14CR_RF24L_SLAVE_REC_aug28b\sketch_14CR_RF24L_SLAVE_REC_aug28b.ino: In function 'void loop()':

sketch_14CR_RF24L_SLAVE_REC_aug28b:25:11: error: void value not ignored as it ought to be

done = radio.read(msg,1);

^

Multiple libraries were found for "nRF24L01.h"
Used: C:\Users\BILL\Documents\Arduino\libraries\nFR24L01
Not used: C:\Users\BILL\Documents\Arduino\libraries\RF24-master
Not used: C:\Users\BILL\Documents\Arduino\libraries\RF24
Not used: C:\Users\BILL\Documents\Arduino\libraries\NRFLite
Multiple libraries were found for "RF24.h"
Used: C:\Users\BILL\Documents\Arduino\libraries\RF24
Not used: C:\Users\BILL\Documents\Arduino\libraries\RF24-master
exit status 1
void value not ignored as it ought to be //!!!!!!!!!!!!!!!ERROR MESSAGE

This report would have more information with
"Show verbose output during compilation"
option enabled in File -> Preferences.

This code will not load Arduino IDE as per error to UNO R3
can only surmise it's something to do with (msg ,1); ????
Please help
regards
Bill White

2 
     done = radio.read(msg,1);

It looks like the read() function does not return a value, ie it is void, but you are trying to assign a value returned by the function.

Which version of the RF24 library are you using ?
Where was it downloaded from ?

3

The librarys are NRF_HAL BY NORDIC SEMICONDUCTER, NRFlite by DAVE PARSON, MYSensors by THE MYSENSOR TEAM, RF24 BY TMR20 VER 1.33,RF24ETHERNET BY TMR20 VER 1.6.2,RF24G BY CAIO MOTTA,RF24MESH BY TMRH 20 1.0.51,RF24NETWORK BY TMRH20 1.0.0 MOST DOWNLODED FROM GITHUB
if they are wrong how do I delete them from the libary
Thanks
Bill White

4

I know that the TMRH libraries work and my advice would be to delete the other RF library folders from the sketchbook\libraries folder to avoid confusion and then stop and restart the IDE

See the advice and examples in Simple nRF24L01+ 2.4GHz transceiver demo

However, looking at the TMRH RF24.h file I see that the read() function is declared void so will not return a value

 void read( void* buf, uint8_t len );

hence the error that you are getting

5

Thanks will have to find another sketch
regards
Bill White

6

will have to find another sketch

You could take a more radical course and write another one yourself, or at least the part that checks whether data is available and, if so, reads it