Dear all,
Yesterday two nRF24l01 boards arrived and I have tried to connect one to an Arduino Uno (transmitter) and the other to an Arduino Nano (receiver), both via an nRF24l01 adapter.
In the image below, the electrical wiring is given for the arduino nano.
The connections for the uno are similar.
For the sake of clarification, the wires are connected as such:
Adapter <-> Nano/Uno
Vcc <-> 5V (5V is required for the adapter, internally it is converted to 3v3)
GND <-> GND
CE <-> D9
CSN <-> D10
SCK <-> D13
M0/MOSI <-> D11
M1/MISO <-> D12
IR0 not connected
The transmitter code (Arduino Uno) is as follows (code based on tutorial Arduino nRF24l01 tutorial :
// SimpleTx - the master or the transmitter
#include <SPI.h>
#include <nRF24L01.h>
#include <RF24.h>
#define CE_PIN 9
#define CSN_PIN 10
const byte slaveAddress[5] = {'R','x','A','A','A'};
RF24 radio(CE_PIN, CSN_PIN); // Create a Radio
char dataToSend[10] = "Message 0";
char txNum = '0';
unsigned long currentMillis;
unsigned long prevMillis;
unsigned long txIntervalMillis = 1000; // send once per second
void setup() {
Serial.begin(9600);
Serial.println("SimpleTx Starting");
radio.begin();
radio.setDataRate( RF24_250KBPS );
radio.setRetries(3,5); // delay, count
radio.openWritingPipe(slaveAddress);
}
//====================
void loop() {
currentMillis = millis();
if (currentMillis - prevMillis >= txIntervalMillis) {
send();
prevMillis = millis();
}
}
//====================
void send() {
bool rslt;
rslt = radio.write( &dataToSend, sizeof(dataToSend) );
// Always use sizeof() as it gives the size as the number of bytes.
// For example if dataToSend was an int sizeof() would correctly return 2
Serial.print("Data Sent ");
Serial.print(dataToSend);
if (rslt) {
Serial.println(" Acknowledge received");
updateMessage();
}
else {
Serial.println(" Tx failed");
}
}
//================
void updateMessage() {
// so you can see that new data is being sent
txNum += 1;
if (txNum > '9') {
txNum = '0';
}
dataToSend[8] = txNum;
}
The receiver code (Arduino Nano), again based on this tutorial Arduino nRF24l01 tutorial :
// SimpleRx - the slave or the receiver
#include <SPI.h>
#include <nRF24L01.h>
#include <RF24.h>
#define CE_PIN 9
#define CSN_PIN 10
const byte thisSlaveAddress[5] = {'R','x','A','A','A'};
RF24 radio(CE_PIN, CSN_PIN);
char dataReceived[10]; // this must match dataToSend in the TX
bool newData = false;
//===========
void setup() {
Serial.begin(9600);
Serial.println("SimpleRx Starting");
radio.begin();
radio.setDataRate( RF24_250KBPS );
radio.openReadingPipe(1, thisSlaveAddress);
radio.startListening();
}
//=============
void loop() {
getData();
showData();
}
//==============
void getData() {
if ( radio.available() ) {
radio.read( &dataReceived, sizeof(dataReceived) );
newData = true;
}
}
void showData() {
if (newData == true) {
Serial.print("Data received ");
Serial.println(dataReceived);
newData = false;
}
}
Unfortunately, if I connect and upload the sketches to the Uno and Nano (via two different USB ports on one laptop) this is all I get:
So the transmitter prints in the Serial monitor that the data delivery failed. I have checked the connections multiple times, I have tried older versions of the RF24 library and the most recent version, but nothing seems to work..
Anyone who might have a clue on what is going wrong here?
