Transmit temp value over rf with NANO not working

Projects Programming
1

i have 2 X RF-Nano's with an integrated rf module
Hardware link here

the idea is to send 3 sensors reading from temp sensors to witch the temp reading is working on the transmitter. but the transmission isn't or the receiver isn't receiving it

only got one temp sensor connected at the moment

transmitter code with LCD attached also

/********************************************************************/
// First we include the libraries
#include <OneWire.h> 
#include <DallasTemperature.h>
#include <SPI.h>
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
#include <nRF24L01.h>
#include <RF24.h>
Adafruit_SSD1306 display(-1);
/********************************************************************/
// Data wire is plugged into pin 2 on the Arduino 
#define ONE_WIRE_BUS 2 
/********************************************************************/
// Setup a oneWire instance to communicate with any OneWire devices  
// (not just Maxim/Dallas temperature ICs) 
OneWire oneWire(ONE_WIRE_BUS); 
/********************************************************************/
// Pass our oneWire reference to Dallas Temperature. 
DallasTemperature sensors(&oneWire);
/********************************************************************/ 
RF24 radio(9, 10);
const uint64_t pipe = 0xE8E8F0F0E1LL;
void setup(void) 
{ 
 // start serial port 
 Serial.begin(9600); 
 Serial.println("Dallas Temperature IC Control Library Demo"); 
 // Start up the library 
 sensors.begin(); 
 radio.begin();
radio.openWritingPipe(pipe);
 // initialize with the I2C addr 0x3C
  display.begin(SSD1306_SWITCHCAPVCC, 0x3C);  

  // Clear the buffer.
  display.clearDisplay();

  // Display Text
  display.setTextSize(1);
  display.setTextColor(WHITE);
  display.setCursor(0,28);
  display.println("Hello world!");
  display.display();
  delay(2000);
  display.clearDisplay();
} 
void loop(void) 
{ 
 // call sensors.requestTemperatures() to issue a global temperature 
 // request to all devices on the bus 
/********************************************************************/
 Serial.print(" Requesting temperatures..."); 
 sensors.requestTemperatures(); // Send the command to get temperature readings 
 Serial.println("DONE"); 
/********************************************************************/
 Serial.print("Temperature is: "); 
 Serial.print(sensors.getTempCByIndex(0)); // Why "byIndex"? 
 float tempc = sensors.getTempCByIndex(0);
radio.write(&tempc, sizeof(float)); 
   // You can have more than one DS18B20 on the same bus.  
   // 0 refers to the first IC on the wire 
    display.setTextSize(1);
  display.setTextColor(WHITE);
  display.setCursor(0,0);
  display.drawRoundRect(0, 18, 120, 35, 8, WHITE);
    display.setTextSize(2);
  display.setTextColor(WHITE);
  display.setCursor(38,0);
  display.println("Temp");
  display.setTextSize(3);
  display.setCursor(18,25);
  display.println(sensors.getTempCByIndex(0));
  display.setTextSize(1);
  display.setTextColor(WHITE);
  display.setCursor(35,57);
  display.println("Degrees C");
  display.display();
  delay(2000);
  display.clearDisplay();
   delay(1000); 
}

and receiver code Just on its own at the moment

#include <SPI.h>
#include <nRF24L01.h>
#include <RF24.h>
#include <Wire.h>




float temperature, temp2;

RF24 radio(9, 10);
const uint64_t pipes[3] = { 0xE8E8F0F0E1LL, 0xF0F0F0F0E2LL, 0xF0F0F0F0E3LL };

void setup(void) {
Serial.begin(9600);
radio.begin();
radio.setDataRate(RF24_250KBPS);
radio.openReadingPipe(1, pipes[1]);
radio.openReadingPipe(2, pipes[2]);
radio.startListening();

delay(1000);

}

void loop(void)
{

if ( radio.available() )
{
delay(50);
radio.read(&temperature, sizeof(temperature));

Serial.print("temperature");

Serial.print(temperature);
Serial.println(" C");

delay(50);
radio.read(&temperature, sizeof(temperature));

Serial.print("Temp 2");

Serial.print(temp2);
Serial.println(" C");
}
else
{
Serial.println("No radio available");
}
delay(1000);
}

tranmitter serial output is

Requesting temperatures...DONE
Temperature is: 25.44

reciver output is

08:41:42.541 -> temperature0.00 C

what am i missing

2

Your TX program seems to be sending one temperature value and your RX program seems to be trying to read two values. Does not seem very sensible to me.

Also, don't have delay()s in the RX program - it should be listening and checking all the time. Do the timing in the TX program.

If these were my programs I would split them up into short single purpose functions so that my code in loop() looks like this

void loop() {
    readSensor();
    sendWirelessData();
    updateDisplay();
}

That way you can easily test each part in isolation.

...R
Simple nRF24L01+ Tutorial
Planning and Implementing a Program

3

why do you read twice "sensors.getTempCByIndex( 0 ) ;"

why delay(50) ? why two reads when you only know about 1 message being there?

--> start first with a simple "hello world" code to ensure you get how to exchange messages between the 2 devices. Once you get that stable, you can start sending your data