NRF24l01 with analog sensors

Projects Programming
1

I am making a wireless multi-function sensor that will use many sensors do gather environmental info when I am finished. I am using a pro-mini with a NRF24 that is sending the gathered data to a wemos D1 mini that is connecting to blynk server. As of now I have the code reading the built in VCC for the mini to monitor the battery, a analog value for the thermistor and a soil moisture sensor. The VCC and temp readings are perfect, but as soon as I add the sensor to the code everything goes haywire. I think the problem is in my code for the transmission?

Any suggestions would be great, thank you.

Here is the Transmitter code

#include <SPI.h>
#include <nRF24L01.h>
#include <RF24.h>
RF24 radio(9, 10); // CE, CSN
const byte addresses [][6] = {"00001", "00002"};    //Setting the two addresses. One for transmitting and one for receiving


int led = 3;
int moisture = A3;
int gTemp = A0;
int gTempON = 5;

 
 
void setup() 
{
  pinMode(led, OUTPUT);
  pinMode(gTempON, OUTPUT);
  
  Serial.begin(9600);
  radio.begin();                            //Starting the radio communication
  radio.openWritingPipe(addresses[0]);      //Setting the address at which we will send the data
  radio.openReadingPipe(1, addresses[1]);   //Setting the address at which we will receive the data
  radio.setPALevel(RF24_PA_MAX);            //You can set it as minimum or maximum depending on the distance between the transmitter and receiver.
}
void loop() 
{

      int V = readVcc();
      
     digitalWrite(gTempON, HIGH); 
      int gTempRAW = analogRead(gTemp);
      int gTempC = map(gTempRAW,266 ,591 ,0 ,36);
       float gTempF  = (gTempC * 1.8) +32;
      
      digitalWrite(gTempON, LOW);


       int value = analogRead(moisture);
       int val = map(value, 460, 860, 100, 0);
     
   radio.stopListening();

    radio.write(&gTempF, sizeof(gTempF));

    radio.write(&val, sizeof(val));

     radio.write(&V,sizeof(V));


       
}
 long readVcc() 
    { 
    long result; // Read 1.1V reference against AVcc 
    ADMUX = _BV(REFS0) | _BV(MUX3) | _BV(MUX2) | _BV(MUX1); delay(2); // Wait for Vref to settle 
    ADCSRA |= _BV(ADSC); // Convert 
    while (bit_is_set(ADCSRA,ADSC)); 
    result = ADCL; 
    result |= ADCH<<8; 
    result = 1126400L / result; // Back-calculate AVcc in mV 
    
    return result; 
    
    }

Here is the reciever

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

#include <ESP8266WiFi.h>
#include <BlynkSimpleEsp8266.h>

char auth[] = "";
char ssid[] = "";
char pass[] = "";

BlynkTimer timer; // Announcing the timer
#define PIN_UPTIME V5


RF24 radio(D2, D8); // CE, CSN
const byte addresses [][6] = {"00001", "00002"};  //Setting the two addresses. One for transmitting and one for receiving

int led_pin = D4;

int V ;
int val ;
float gTempF ;

// This function tells Arduino what to do if there is a Widget
// which is requesting data for Virtual Pin (5)
BLYNK_READ(PIN_UPTIME)
{
  // This command writes Arduino's uptime in seconds to Virtual Pin (5) 
Blynk.virtualWrite(PIN_UPTIME, millis() / 1000);   
}
  



void setup() 
{

  Blynk.begin(auth, ssid, pass);
timer.setInterval(1000L, TimerV); 

  
Serial.begin(9600);
  pinMode(led_pin, OUTPUT);
  radio.begin();                           //Starting the radio communication
  radio.openWritingPipe(addresses[1]);     //Setting the address at which we will send the data
  radio.openReadingPipe(1, addresses[0]);  //Setting the address at which we will receive the data
  radio.setPALevel(RF24_PA_MAX); //You can set it as minimum or maximum depending on the distance between the transmitter and receiver. 
}

void TimerV()
{ 
  
 radio.startListening(); 
  if(!radio.available());
  {
    radio.read(&val,sizeof(val));

    radio.read(&gTempF,sizeof(gTempF));
 
    radio.read(&V, sizeof(V));
  
  
  
  
  } 
   Blynk.virtualWrite(V2, gTempF);
   Blynk.virtualWrite(V0, val);
   Blynk.virtualWrite(V1, V);
}
void loop() 
{  



  Blynk.run();
  timer.run();
  }
2

everything goes haywire

Details please

3

You should not be sending the three values in three separate messages like this.

    radio.write(&gTempF, sizeof(gTempF));

    radio.write(&val, sizeof(val));

     radio.write(&V,sizeof(V));

Just put the values in an array or a struct and send them all in one message.

On the one hand your code is sending the messages with no time between them for the receiver to deal with them and, on the other hand, if the receiver misses one it will get them all out of sync.

Have a look at the examples in this Simple nRF24L01+ Tutorial

...R

4

Create a header file with a struct for the message data and include that header in both ends.

//global.h
struct RF_MESSAGE {
  byte a, b;
  int c;
};

//sender.ino
#include "global.h"

void loop() {
  RF_MESSAGE msg;
  msg.a = 123;
  msg.b = 234;
  msg.c = 12345;
  radio.write(&msg, sizeof(msg));
  delay(1000);
}

//receiver.ino
#include "global.h"

void loop() {
  if (radio.available()) {
    RF_MESSAGE msg;
    radio.read(&msg, sizeof(msg));
    Serial.println(F("Message received:"));
    Serial.println(msg.a);
    Serial.println(msg.b);
    Serial.println(msg.c);
  }
}

This is IMO the best way of transmitting "bundled" data of various types which is what you want.