nRF24L01 2.4GHz tranceiver - ATMega328p

[sheffladreece]

I am currently attempting to communicate between two- nRF24L01 2.4GHz tranceivers using a ATMega328p with use of the USBtinyISP in C/C++ ... Is there any chance that anyone would have any coding regarding the setup/ communcation process or be able to offer any advice at all regarding this setup or coding of... I have limited experience, having only started coding and building electronics projects over the last 2 days so please bare with me if I do not understand elements of your replys. Thanks.

 

[(*steve*)]

Whilst I will keep my clothes on, I am happy to share some code.

It will have to wait for quite a few hours though.

First things:

1 are you powering the device from 3.3v?

2 are you using the small modules with 8 or10 pins? (beware that these have very different pinouts)

3 are you using the arduino compiler?

4 have you downloaded one of the available libraries and tried the demos they come with?

 

[(*steve*)]

My strong recommendation is to get the appropriate libraries (RF24, and maybe RF24Network) and go through the examples.

Here is the simplest bit of code I have. It has the advantage of operating stand-alone, that is, it only requires a single NRF24L01. It is a fancy signal strength meter.

/*
  Combines RF24's scanner with the LCD output to make a standalone scanner
   
 - - - - - - - - - - - - - - - - - -
 
  The circuit:
 * LCD pin 1 (gnd) to gnd
 * LCD pin 2 (Vcc) to +5v
 * LCD pin 3 (VO) to wiper of 20k pot between Vcc and gnd (contrast adj)
 * LCD pin 4 (RS) to digital pin 7
 * LCD pin 5 (R/W) to gnd
 * LCD pin 6 (clock/enable) to digital pin 6
 * LCD pin 7 (D0) UNUSED
 * LCD pin 8 (D1) UNUSED
 * LCD pin 9 (D2) UNUSED
 * LCD pin 10 (D3) UNUSED
 * LCD pin 11 (D4) to digital pin 5
 * LCD pin 12 (D5) to digital pin 4
 * LCD pin 13 (D6) to digital pin 3
 * LCD pin 14 (D7) to digital pin 2
 http://www.arduino.cc/en/Tutorial/LiquidCrystal
 - - - - - - - - - - - - - - - - - -
 Example to detect interference on the various channels available.
 This is a good diagnostic tool to check whether you're picking a
 good channel for your application.
 Inspired by cpixip.
 See http://arduino.cc/forum/index.php/topic,54795.0.html

 The circuit:
 * nRF24L01 pin 1 gnd to gnd
 * nRF24L01 pin 2 Vcc tp 3v3
 * nRF24L01 pin 3 CE to 9
 * nRF24L01 pin 4 CSN to 10
 * nRF24L01 pin 5 SCK to 13
 * nRF24L01 pin 6 MOSI to 11
 * nRF24L01 pin 7 MISO to 12
 * nRF24L01 pin 8 IRQ UNUSED
 */

// include the library code:
#include <LiquidCrystal.h>
#include <SPI.h>
#include "nRF24L01.h"
#include "RF24.h"
#include "printf.h"

const
  uint8_t num_rows = 2;
  uint8_t num_cols = 16;
  uint8_t scan_wide = (num_rows - 1) * num_cols;


// initialize the library with the numbers of the interface pins
LiquidCrystal lcd(7, 6, 5, 4, 3, 2);

//
// Hardware configuration
//

// Set up nRF24L01 radio on SPI bus plus pins 9 & 10

RF24 radio(2,3);

//
// Channel info
//

const
  uint8_t num_channels = 128;
  uint8_t grp_size = num_channels / scan_wide;
  uint8_t values[num_channels];

void setup() {
  // set up the LCD's number of columns and rows:
  lcd.begin(num_cols, num_rows);
  // Print a message to the LCD.
  lcd.print("nRF24L01 Scanner");
 
  radio.begin();
  radio.setAutoAck(false);

  // Get into standby mode
  radio.startListening();
  radio.stopListening();

}

const int num_reps = 100;

void loop() {
  // set the cursor to column 0, line 1
  // (note: line 1 is the second row, since counting begins with 0):
  lcd.setCursor(0, 1);

  // Clear measurement values
  memset(values,0,sizeof(values));

  // Scan all channels num_reps times
  int rep_counter = num_reps;
  while (rep_counter--)
  {
  int i = num_channels;
  while (i--)
  {
  // Select this channel
  radio.setChannel(i);

  // Listen for a little
  radio.startListening();
  delayMicroseconds(128);
  radio.stopListening();

  // Did we get a carrier?
  if ( radio.testCarrier() )
  ++values[i];
  }
  }

  // Print out channel measurements, clamped to a single hex digit
  int i = 0;
  while ( i < num_channels )
  {
  int group = 0;
   
  for ( int j=0; j < grp_size; j++)
  {
  group += values[i];
  ++i;
  }
   
  lcd.print(min(0xf,group), HEX);
  }
}