Arduino Mega with nRF24L01+ module

Question

I am having trouble getting this module to work using the tmrh20 lib. I am using these modules with two arduino mega and a 3.3V external power supply. I also placed 10 uF in parallel with the modules power pin. I would really appreciate any comments or suggustions.

In the code below all I am trying to do is turn on a led. Here are my pin assignment for both arduinos CE -> 7 CSN -> 8 SCK -> 52 MOSI -> 51 MISO -> 50 IRQ -> unconnected

Transmitter

//#include <DigitalIO.h>
#include <SPI.h>
#include "RF24.h"
#include <printf.h>
RF24 radio(7,8);
const uint64_t pipe = 0xE8E8F0F0E1LL;
unsigned long msg = 375983;

void setup() {
    Serial.begin(115200);
    printf_begin();
    Serial.println("Transmitter");
    pinMode(9, INPUT);
    radio.begin();
    radio.setChannel(108);
    radio.openWritingPipe(pipe);
    radio.startListening();
    radio.printDetails();
}

void loop() {
  radio.stopListening();
  if (digitalRead(9) == HIGH)
  {
    while (!radio.write(&msg, sizeof(msg))){
      radio.write(&msg, sizeof(msg));
}
  Serial.println("Sending.....");
  }
  else {
    Serial.println("Awaiting Input....");
  }
  delay(500);

}

print detail report

STATUS = 0xff RX_DR=1 TX_DS=1 MAX_RT=1 RX_P_NO=7 TX_FULL=1
RX_ADDR_P0-1 = 0xffffffffff 0xffffffffff
RX_ADDR_P2-5 = 0x7f 0xff 0x7f 0xff
TX_ADDR = 0x0000000000
RX_PW_P0-6 = 0xff 0x7f 0xff 0x7f 0xff 0xff
EN_AA = 0xff
EN_RXADDR = 0xff
RF_CH = 0xff
RF_SETUP = 0xff
CONFIG = 0xff
DYNPD/FEATURE = 0x7f 0xff
Data Rate = 1MBPS
Model = nRF24L01
CRC Length = Disabled
PA Power = PA_MAX

Receiver

//#include <DigitalIO.h>
#include <SPI.h>
#include "RF24.h"
#include <printf.h>
RF24 radio(7,8);
const uint64_t pipe = 0xE8E8F0F0E1LL;
unsigned long msg;

void setup() {
    Serial.begin(115200);
    printf_begin();
    Serial.println("Receiver");
    pinMode(9, OUTPUT);
    radio.begin();
    radio.setChannel(108);
    radio.openReadingPipe(0,pipe);
    radio.printDetails();

}

void loop() {
   radio.startListening();
   digitalWrite(9, LOW);
  if(radio.available()){
    while(radio.available())
    {
    radio.read(&msg, sizeof(msg));
    Serial.println("Incoming...");
    delay(500);
    Serial.println(msg);
    }
  }
  else{
    Serial.println("No Msg");
  }
  radio.stopListening();
  Serial.println(msg);
  if (msg == 375983){
    digitalWrite(9, HIGH);
    Serial.println(msg);
  }
  delay(500);
}

print detail report

STATUS = 0x00 RX_DR=0 TX_DS=0 MAX_RT=0 RX_P_NO=0 TX_FULL=0
RX_ADDR_P0-1 = 0x0000000000 0x0000000000
RX_ADDR_P2-5 = 0x00 0x00 0x00 0x00
TX_ADDR = 0x0000000000
RX_PW_P0-6 = 0x00 0x00 0x00 0x00 0x00 0x00
EN_AA = 0x00
EN_RXADDR = 0x00
RF_CH = 0x00
RF_SETUP = 0x00
CONFIG = 0x00
DYNPD/FEATURE = 0x00 0x00
Data Rate = 1MBPS
Model = nRF24L01
CRC Length = Disabled
PA Power = PA_MIN

UPDATE: Transmitter PrintDetail

STATUS       = 0x0e RX_DR=0 TX_DS=0 MAX_RT=0 RX_P_NO=7 TX_FULL=0
RX_ADDR_P0-1     = 0x00000000e1 0xc2c2c2c2c2
RX_ADDR_P2-5     = 0xc3 0xc4 0xc5 0xc6
TX_ADDR      = 0x00000000e1
RX_PW_P0-6   = 0x20 0x00 0x00 0x00 0x00 0x00
EN_AA        = 0x3f
EN_RXADDR    = 0x02
RF_CH        = 0x6c
RF_SETUP     = 0x07
CONFIG       = 0x0f
DYNPD/FEATURE    = 0x00 0x00
Data Rate    = 1MBPS
Model        = nRF24L01+
CRC Length   = 16 bits
PA Power     = PA_MAX

Results form tmrh20 Getting Started Example

First Arduino

Sent 8340224, Got response 0, Round-trip delay 547172 microseconds
Now sending
Sent 9889124, Got response 0, Round-trip delay 511072 microseconds
Now sending
Sent 11401920, Got response 0, Round-trip delay 43348 microseconds
Now sending
Sent 12446992, Got response 0, Round-trip delay 635580 microseconds
Now sending
Sent 14084352, Got response 0, Round-trip delay 1620788 microseconds
Now sending
Sent 16706968, Got response 0, Round-trip delay 1227548 microseconds
Now sending
Sent 18936340, Got response 0, Round-trip delay 145372 microseconds

Second Arduino

*** PRESS 'T' to begin transmitting to the other node

The second arduino is not printing anything on the serial monitor, no matter what I enter.

Answer 1

(not enough point to comment, so here's a potential answer) I had enormous troubles getting these things to work reliably. I tried all kinds of caps over the power supply. In the end I went for a 1$ piggy back board that takes 5v input and regulates to 3.3V. It also has the right pin female header to fit the nfr nicely. Since then I've had no issues. I also did a bit of experimentation and found that the RX side was the side giving problems.

Answer 2

Try these:

• Set pin 9 on the TX side as a pulled-up input i.e. pinMode(9, INPUT_PULLUP); Connect one end of the switch to GND and the other to pin 9. Then in your code, test for a button press like this: if (digitalRead(9) == LOW){...}
• Use a byte array for holding the address instead of the 64-bit int you're using.
• Remove the stopListening() call in your RX loop(); there is no need for it since all its doing is receiving.
• Remove the 500 ms delays in the RX loop() just in the unlikely case that its causing you to lose bytes