nRF24L01 leaves out certain characters during transmission

[Kishore]

Hi, I am using nRF24L01 as a part of a larger project that involves communication between two such transceivers sending and receiving data. I am trying to get a similar but simpler code working with the module. So far, I have established communication between them. Characters are sent and received using arrays. The problem is that the receiver's serial monitor does not print all the characters. Sometimes the last character is not printed, and sometimes the last two characters are not printed. When I do a second transmission, the missing characters from the first transmission get printed. I have been trying to solve this for days now. Any help is greatly appreciated.  I am using an arduino nano and another arduino uno with the 2 transceivers. They also have a 100μF decoupling capacitor between 3.3V and GND. 

Master's code(Transmitter) and the Slave's code(Receiver) are attached with this thread.

NRF24L01_Slave_EbyE.inoNRF24L01_Master_EbyE.ino

[Håkon Alseth]

Hi,

 

You will set the flag even if no chars are available here:

void read() {
  p = &text[0];
  for (i = 0; Serial.available(); p++, i++) {
    *p = Serial.read();
  }
  text[i + 1] = '\0';
  flag = 1;
}

I would recommend that you re-write this function to something like

if (Serial.available()) {

  /* insert for loop for Read out data and set last byte \0 */ 

  flag = 1;

}

 

Could you try this and see if it works better?

 

Kind regards,

Håkon

[Kishore]

No. That didn't improve anything. I changed this

void read() {
  p = &text[0];
  for (i = 0; Serial.available(); p++, i++) {
    *p = Serial.read();
  }
  text[i + 1] = '\0';
  flag = 1;
}

  

to this. 

void read() {
  p = &text[0];
  if(Serial.available()){
  for (i = 0; Serial.available(); p++, i++) {
    *p = Serial.read();
  }
  text[i + 1] = '\0';
  flag = 1;
}

}

Still nothing has improved. 

[Håkon Alseth]

Hi,

 

Is this the library that you are using? It seems that this one is the optimized fork of the original project:

https://github.com/nRF24/RF24

I'd recommend that you check the "issues" part of the github project, in case any of the known issues matches yours.

 

Kind regards,

Håkon

[Kishore]

https://github.com/maniacbug/RF24/

That is the library that I am using. And what do you mean by optimized fork of the original project. Sorry, if this sounds so basic, I am a beginner actually. 

Also, I have another question. I test my nRF modules in a place that is swarmed with a lot of wifi and many people use wireless mice for their laptops which also operate in the 2.4Ghz frequency. Is there any chance that this maybe contributes to the problem that I've been encountering.?

[Håkon Alseth]

Hi,

 

The original "RF24" project has not been updated since 2013. The optimized fork that I linked to is actively being developed on, so it's recommended that you use that one, and see if the issue is still present.

Kishore said:

Also, I have another question. I test my nRF modules in a place that is swarmed with a lot of wifi and many people use wireless mice for their laptops which also operate in the 2.4Ghz frequency.

That should not matter.

 

Kind regards,

Håkon