Advice about RF nRF24L01+ to send/receive sensory information

[Walyson Albuquerque Machado]

@mfalkvidd Thank you! I really appreciated your advices.

I'm using two Arduinos UNO and at the moment I can see battery level using a lcd and a voltage sensor module.

Now I'm going to build the nRF module, but I have a doubt about the Arduino UNO pin using SPI interface MOSI, MISO and SCK.

One UNO with nRF > pin 11, 12 and 13 / SD card > pin 11, 12 and 13

Another UNO with nRF > pin 11, 12 and 13 / lcd > pin 11, 12, 2, 3, 4 and 5

They use the same pins, what am I gonna do? Put them in parallel?

Thanks!

[mfalkvidd]

@Walyson-Albuquerque-Machado it depends on which libraries and which lcd and sd card reader you are using. Some can be put in parallell, with addition of a slave select pin. An alternative is to use softspi as described in https://www.mysensors.org/build/ethernet_gateway and https://github.com/mysensors/MySensors/blob/development/examples/GatewayW5100/GatewayW5100.ino#L57

With softspi, an extra spi bus is created and one of the components (the w5100 ethernet module in the above example) is connected to the extra bus so it does not interfere with the nrf.

https://learn.sparkfun.com/tutorials/serial-peripheral-interface-spi is a good start if you want to learn more about spi.

[Walyson Albuquerque Machado]

Hey!
Thanks @mfalkvidd !

I'm trying to make the module nRF24l01+ work with the micro SD card in parallell and I'm having some trouble.

The micro SD card is working, but the nRF24l01+ not.
The nRF24l01+ works fine when there's no micro SD card.

Can anyone give me a help, please!?

TX:

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

#define REFRESH_TIME 1000

RF24 radio (9, 10);
byte enderecos[][6] = {"1node"};

float dadosenviados[2];

// Bateria
int sensorTensaoDC = A0;
float valorTensaoDC;
int amostragem = 1000;
float mediaTotalTensaoDC = 0;
float R1 = 28000.0;  
float R2 = 7600.0;
int sensorValue_aux = 0;
float voltsporUnidade = 0.004887586;// 5%1023

//Velocidade
unsigned long lastRefresh = millis();   
float circMetric = 0.17;
volatile long loopCount = 0;   


void setup () 
{  
  analogReference(DEFAULT);
  pinMode(A0, INPUT);
  
  attachInterrupt(0, speedCalc, RISING); 

  
  radio.begin();
  radio.openWritingPipe(enderecos[0]);  
  radio.stopListening(); 
}
  
void bateria ()
{
  mediaTotalTensaoDC = 0;
  
  for(int i=0; i < amostragem ; i++)
  {
    valorTensaoDC = analogRead(sensorTensaoDC);
    valorTensaoDC =(valorTensaoDC*voltsporUnidade);
    mediaTotalTensaoDC = mediaTotalTensaoDC+ (valorTensaoDC / (R2/(R1+R2)));
    delay(1);
  }
  dadosenviados[0] = mediaTotalTensaoDC / amostragem;  
}

void velocidade ()
{
  if (millis() - lastRefresh >= REFRESH_TIME)
  { 
    
    detachInterrupt(0);    
    
    dadosenviados[1] = (3600*circMetric*loopCount)/(millis() - lastRefresh);
        
    loopCount = 0;
    lastRefresh = millis();
    
    attachInterrupt(0, speedCalc, RISING);
  }  
}

void speedCalc()
{
  loopCount++;
}

void envio ()
{
  radio.write(&dadosenviados, sizeof(dadosenviados));
  delay(10);
}
  
void loop()
{ 
  dadosenviados[0] = 0;
  dadosenviados[1] = 0;
  bateria();
  velocidade();
  envio();
}

RX:

#include <SD.h>
#include <SPI.h>
#include <RF24.h>
#include <LiquidCrystal.h>

#define CE_PIN   9 // RF
#define CSN_PIN 10 //RF

#define SS_P 8// SD

RF24 radio (9, 10);


byte enderecos[][6] = {"1node"};

File dataFile;

LiquidCrystal lcd(3, 2, 7, 6, 5, 4);

String dadosrecebidos[2];

void setup () 
{

pinMode(CSN_PIN, OUTPUT); // RF
pinMode(CE_PIN, OUTPUT); // RF
pinMode(SS_P, OUTPUT); // SD 
  
  digitalWrite(SS_P, HIGH); 
  digitalWrite(CSN_PIN, HIGH); 
  digitalWrite(CE_PIN, HIGH);

  SPI.begin();
  delay(50);		
 
  digitalWrite(CSN_PIN, LOW);                 
  digitalWrite(CE_PIN, LOW);
    
    radio.begin();
    radio.openReadingPipe(1, enderecos[0]);
    radio.startListening();
    
  digitalWrite(CSN_PIN, HIGH);
    
  lcd.begin(20, 4);
  lcd.clear();
  lcd.setCursor(5, 0);
  lcd.print("Teste 1.6");
  delay(5000);
  lcd.setCursor(3, 2);
  lcd.print("Carregando...");
  delay(5000);
  lcd.clear();
  
  digitalWrite(SS_P, LOW);
    
    if (SD.begin(SS_P))
  {
    lcd.setCursor(0, 0);
    lcd.print("Cartao presente!");
    lcd.setCursor(0, 1);
    lcd.print("Pronto para gravar.");
    delay(5000);
    lcd.setCursor(3, 3);
    lcd.print("Iniciando...");
    delay(5000);
  }
  else
  {
    lcd.setCursor(0, 0);
    lcd.print("Insira o cartao!");
    lcd.setCursor(0, 1);
    lcd.print("Se ja inseriu,");
    lcd.setCursor(0, 2);
    lcd.print("verifique o");
    lcd.setCursor(0, 3);
    lcd.print("cartao");
    delay(5000);
  }
    dataFile = SD.open("datalog.txt", FILE_WRITE);
    if (dataFile)
    { 
    dataFile.println("Tensão e velocidade");
     
    dataFile.close();
    }
    else 
    {
    dataFile.println("Erro");
    }
  digitalWrite(SS_P, HIGH);
} 

void recebido ()
{
  digitalWrite(CE_PIN, LOW);  
  digitalWrite(CSN_PIN, LOW); 
   
   if (radio.available())
   {
    while (radio.available())
    {
      radio.read(&dadosrecebidos, sizeof(dadosrecebidos));
    }
   
    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("TENSAO");
    lcd.setCursor(7, 0);
    lcd.print(dadosrecebidos[0]);
    lcd.print("VOLTS");
    lcd.setCursor(0, 1);
    lcd.print("VELOCIDADE");
    lcd.setCursor(11, 1);
    lcd.print(dadosrecebidos[1]);
    lcd.print("KM/H");
   }
   
   digitalWrite(CSN_PIN, HIGH);
} 

void gravar()
{
    digitalWrite(SS_P, LOW); 

  // make a string for assembling the data to log:
  String dataString = ""; //this line simply erases the string
  dataString += "Tensao ";
  dataString += (dadosrecebidos[0]);
  dataString += " VOLTS";
  dataString += " / ";     //puts a comma between the two bits of data
  dataString += "Velocidade ";
  dataString += (dadosrecebidos[1]);
  dataString += " KM/H";
  delay (1000);

  dataFile = SD.open("datalog.txt", FILE_WRITE);
 
  // if the file is available, write to it:
  if (dataFile) 
  {
    dataFile.println(dataString);
    dataFile.close();
  }
  // if the file isn't open, pop up an error:
  else 
  {
    dataFile.println("Erro");
  }
    digitalWrite(SS_P, HIGH); 
}

void loop () 
{
  recebido();
  gravar();
}```

[AWI]

@Walyson-Albuquerque-Machado from your sketch I conclude that you are not using MySensors as framework for creating you sensor and logger.
@mfalkvidd gave you some good suggestions for using a SPI bus interface.
The purpose of this forum is to work with/ discuss the MySensors framework.

Give MySensors a try and discover that it solves a lot of your low level interface issues.

[Walyson Albuquerque Machado]

@AWI Hi.
Sure, I'm going to try and then I come back here.

Thanks.

[Walyson Albuquerque Machado]

Hey. I'm trying to use Mysensors, but I got these errors. Are there a specific command that I should use? I didn't find any example.

error: 'RF24' does not name a type RF24 radio(MY_RF24_CE_PIN, MY_RF24_CS_PIN);

error: 'radio' was not declared in this scope radio.begin();

[AWI]

@Walyson-Albuquerque-Machado The MySensors site is full of examples. You probably have an incomplete instalation or conflicting (RF24) libararies. Try getting started

[Walyson Albuquerque Machado]

I'm getting started and I'm researching about Mysensors. I would like some tips, please.

I know that I must set this first:

#define RF24_CE_PIN       9
#define RF24_CS_PIN      10
#define RF24_PA_LEVEL      RF24_PA_MAX
#define RF24_PA_LEVEL_GW   RF24_PA_LOW
#define RF24_CHANNEL     76
#define RF24_DATARATE      RF24_250KBPS
#define RF24_BASE_RADIO_ID ((uint64_t)0xA8A8E1FC00LL)
#define SOFTSPI
#ifdef SOFTSPI
  const uint8_t SOFT_SPI_MISO_PIN = 16;
    const uint8_t SOFT_SPI_MOSI_PIN = 15;
    const uint8_t SOFT_SPI_SCK_PIN = 14;
#endif

#include <MyConfig.h>
#include <MySensors.h>

And I know that in 2.0.x I don't need to set this:

 .begin();

But I don't know how to define in Mysensors when it's Writing / stopListening and Reading / startListening

radio.openWritingPipe(enderecos[0]);  
radio.stopListening(); 

openReadingPipe(1, enderecos[0]);
startListening();

Also how to Write the sensor information and Read:

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

 if (radio.available())
   {
    while (radio.available())
    {
      radio.read(&dadosrecebidos, sizeof(dadosrecebidos));
    }

Is this how I send the sensor information? If so, how do I read?

void presentation()  
{ 
  sendSketchInfo("Distance Sensor", "1.0");
  present(CHILD_ID, S_DISTANCE);
}

[AWI]

@Walyson-Albuquerque-Machado You are getting on track. You should not bother about the radio, it is hidden (abstracted) in MySensors. You send with the "send" function and receive with the "receive" function. Everything as described in the API.

I would suggest you build a simple sensor/sketch (i.e. relay actuator) before diving deeper.

I am still taking some tough lessons combining devices on the SPI bus. Like @mfalkvidd mentioned in his post

Let us know your progress.

[Walyson Albuquerque Machado]

I'm trying to do the battery level example and I'm getting this:

Starting sensor (RNNNA-, 2.0.0)
TSM:INIT
TSM:RADIO:OK
TSP:ASSIGNID:OK (ID=10)
TSM:FPAR
TSP:MSG:SEND 10-10-255-255 s=255,c=3,t=7,pt=0,l=0,sg=0,ft=0,st=bc:
TSP:MSG:READ 10-10-255 s=255,c=3,t=7,pt=0,l=0,sg=0:
TSP:MSG:BC
TSM:FPAR
TSP:MSG:SEND 10-10-255-255 s=255,c=3,t=7,pt=0,l=0,sg=0,ft=0,st=bc:
TSP:MSG:READ 10-10-255 s=255,c=3,t=7,pt=0,l=0,sg=0:
TSP:MSG:BC
TSM:FPAR
TSP:MSG:SEND 10-10-255-255 s=255,c=3,t=7,pt=0,l=0,sg=0,ft=0,st=bc:
TSM:FPAR
TSP:MSG:SEND 10-10-255-255 s=255,c=3,t=7,pt=0,l=0,sg=0,ft=0,st=bc:
!TSM:FPAR:FAIL
!TSM:FAILURE
TSM:PDT

What does it mean? Why can't I read the serial messages?

[AWI]

@Walyson-Albuquerque-Machado
Your node does not find a parent (gateway) so no response from another node. For documentation: a little indirect but this post by @mfalkvidd should help.

[Walyson Albuquerque Machado]

Ok, I'm getting there. I appreciate your advices, thanks. :smile:
Now I can see the battery level in the serial. But I didn't understand how to receive the battery level in the gateway to show on my LCD display.

Gateway ok:

0;255;3;0;9;Starting gateway (RNNGA-, 2.0.0)
0;255;3;0;9;TSM:INIT
0;255;3;0;9;TSM:RADIO:OK
0;255;3;0;9;TSM:GW MODE
0;255;3;0;9;TSM:READY
0;255;3;0;14;Gateway startup complete.
0;255;0;0;18;2.0.0
0;255;3;0;9;No registration required
0;255;3;0;9;Init complete, id=0, parent=0, distance=0, registration=1
0;255;3;0;9;TSP:MSG:READ 10-10-255 s=255,c=3,t=7,pt=0,l=0,sg=0:
0;255;3;0;9;TSP:MSG:BC
0;255;3;0;9;TSP:MSG:FPAR REQ (sender=10)
0;255;3;0;9;TSP:CHKUPL:OK (FLDCTRL)
0;255;3;0;9;TSP:MSG:GWL OK
0;255;3;0;9;TSP:MSG:SEND 0-0-10-10 s=255,c=3,t=8,pt=1,l=1,sg=0,ft=0,st=ok:0
0;255;3;0;9;TSP:MSG:READ 10-10-0 s=255,c=3,t=24,pt=1,l=1,sg=0:1
0;255;3;0;9;TSP:MSG:PINGED (ID=10, hops=1)
0;255;3;0;9;TSP:MSG:SEND 0-0-10-10 s=255,c=3,t=25,pt=1,l=1,sg=0,ft=0,st=ok:1
0;255;3;0;9;TSP:MSG:READ 10-10-0 s=255,c=3,t=15,pt=6,l=2,sg=0:0100
0;255;3;0;9;TSP:MSG:SEND 0-0-10-10 s=255,c=3,t=15,pt=6,l=2,sg=0,ft=0,st=ok:0100
0;255;3;0;9;TSP:MSG:READ 10-10-0 s=255,c=0,t=17,pt=0,l=5,sg=0:2.0.0
10;255;0;0;17;2.0.0
0;255;3;0;9;TSP:MSG:READ 10-10-0 s=255,c=3,t=6,pt=1,l=1,sg=0:0
10;255;3;0;6;0
0;255;3;0;9;TSP:MSG:READ 10-10-0 s=255,c=3,t=11,pt=0,l=13,sg=0:Battery Meter
0;255;3;0;9;TSP:MSG:READ 10-10-0 s=255,c=3,t=12,pt=0,l=3,sg=0:1.0
0;255;3;0;9;TSP:MSG:READ 10-10-0 s=255,c=3,t=26,pt=1,l=1,sg=0:2
0;255;3;0;9;TSP:MSG:SEND 0-0-10-10 s=255,c=3,t=27,pt=1,l=1,sg=0,ft=0,st=ok:1

Node ok:

Starting sensor (RNNNA-, 2.0.0)
TSM:INIT
RF24:write register, reg=0, value=14
RF24:read register, reg=6, value=35
RF24:flushRX
TSM:RADIO:OK
RF24:start listening
RF24:write register, reg=10, value=10
TSP:ASSIGNID:OK (ID=10)
TSM:FPAR
RF24:stop listening
RF24:write register, reg=0, value=14
RF24:open writing pipe, recipient=255
RF24:write register, reg=10, value=255
RF24:send message to 255, len=7
RF24:flushTX
RF24:MAX_RT
TSP:MSG:READ 0-0-10 s=255,c=3,t=8,pt=1,l=1,sg=0:0
TSP:MSG:FPAR RES (ID=0, dist=0)
TSP:MSG:FPAR (PPAR FOUND)
TSP:MSG:PAR OK (ID=0, dist=1)
TSM:FPAR:OK
TSM:ID
TSM:CHKID:OK (ID=10)
TSM:UPL
TSP:PING:SEND (dest=0)
TSP:MSG:PONG RECV (hops=1)
TSP:CHKUPL:OK
TSM:UPL:OK
TSM:READY
Init complete, id=10, parent=0, distance=1, registration=1
Battery Voltage: 0.00 V
Battery Voltage: 5.91 V
Battery Voltage: 5.91 V

[AWI]

@Walyson-Albuquerque-Machado Back to one of your previous posts. What kind of LCD display are you using. Do you have one with I2C interface?

[Walyson Albuquerque Machado]

Hey. I don't have I2C interface. Do I need it?

I have one like this, 20x4:

[AWI]

@Walyson-Albuquerque-Machado It is much easier to connect an I2C display (only 2 wires and power).But if you have pins left on your arduino and the patience to solder you're ok.

an adapter plate:

[Walyson Albuquerque Machado]

I have pins and I have already done this. :stuck_out_tongue_closed_eyes:

[Walyson Albuquerque Machado]

Is that how I send ? Can I use BINARY to my hall effect sensor? I'm using the digital pin to count every time it passes through a magnet.

MyMessage msg(NODE_ID, V_STATUS);

float value = 0;

void presentation()
{
    present(NODE_ID, S_BINARY);
}

void loop()
{
    send(msg.set(value));
}

Is that how I receive?

void receive(const MyMessage &message) {
    // Handle incoming message
}

[Walyson Albuquerque Machado]

Please, someone tell me how to get the voltage that i'm receiving. I've tried many things, I don't know why this doesn't work.

msgvolt.getFloat();

I can see the battery in the gateway through serial, but I don't know how to get it to show on the LCD.

Node:

#define MY_DEBUG 
#define MY_DEBUG_VERBOSE_RF24
#define MY_RADIO_NRF24
#define DESTINATION_NODE 0      
#define MY_NODE_ID 10
#define MY_PARENT_NODE_ID  0
#define MY_PARENT_NODE_IS_STATIC
#define MY_RF24_CE_PIN 9
#define MY_RF24_CS_PIN 10
#define MY_RF24_PA_LEVEL RF24_PA_LOW
#define MY_RF24_PA_LEVEL_GW RF24_PA_LOW
#define MY_RF24_CHANNEL 76
#define MY_RF24_DATARATE RF24_250KBPS


#include <SPI.h>
#include <MySensors.h>


int sensorTensaoDC = A0;
float valorTensaoDC;
int amostragem = 1000;
float mediaTotalTensaoDC = 0;
float R1 = 28000.0;  
float R2 = 7600.0;
int sensorValue_aux = 0;
float voltsporUnidade = 0.005278592; // 5%1023

float dadosenviados;


MyMessage msgvolt(4, V_VOLTAGE);

void setup()  
{
  analogReference(DEFAULT);
  pinMode(A0, INPUT);
}

void presentation() {
   sendSketchInfo("Battery Meter", "1.0");
   present(4, S_MULTIMETER, "Voltage", true);
}

void loop()
{
   mediaTotalTensaoDC = 0;
  for(int i=0; i < amostragem ; i++)
  {
    valorTensaoDC = analogRead(sensorTensaoDC);

    valorTensaoDC =(valorTensaoDC*voltsporUnidade);
    mediaTotalTensaoDC = mediaTotalTensaoDC+ (valorTensaoDC / (R2/(R1+R2)));
  }
  dadosenviados = mediaTotalTensaoDC / amostragem;
  
  
   Serial.print("Battery Voltage: ");
   Serial.print(dadosenviados);
   Serial.println(" V");

 send(msgvolt.setDestination(DESTINATION_NODE).set(dadosenviados, 2), 1);
  wait(2000);

}

Gateway:

#define MY_DEBUG
#define MY_RADIO_NRF24
#define MY_GATEWAY_SERIAL
#define MY_NODE_ID 0
#define DESTINATION_NODE 10 
#define MY_RF24_CE_PIN 9
#define MY_RF24_CS_PIN 10
#define MY_RF24_PA_LEVEL RF24_PA_LOW
#define MY_RF24_PA_LEVEL_GW RF24_PA_LOW
#define MY_RF24_CHANNEL 76
#define MY_RF24_DATARATE RF24_250KBPS

#include <MySensors.h>
#include <LiquidCrystal.h>
#include <SPI.h>

float dadosenviados = 0;

MyMessage msgvolt(4, V_VOLTAGE);

LiquidCrystal lcd(3, 2, 7, 6, 5, 4);

void setup()  
{
  lcd.begin(20, 4);
  lcd.clear();
  lcd.setCursor(5, 0);
  lcd.print("Teste 1.6");
  delay(5000);
  lcd.setCursor(3, 2);
  lcd.print("Carregando...");
  delay(5000);
  lcd.clear();
}

void presentation() {
      sendSketchInfo("Battery Meter", "2.0");
      present(4, S_MULTIMETER);
}

void receive(const MyMessage &msgvolt) {
  saveState(msgvolt.sensor, msgvolt.getFloat());
 dadosenviados = msgvolt.getFloat();
request(4, V_VOLTAGE, 10);

}         

void incomingMessage(const MyMessage &msgvolt) {

request(4, V_VOLTAGE, 10);
dadosenviados = msgvolt.getFloat();

    lcd.clear();
    lcd.setCursor(0, 0);
    lcd.print("TENSAO");
    lcd.setCursor(7, 0);
    lcd.print(dadosenviados);
    lcd.print("VOLTS");
    lcd.setCursor(0, 1);
    lcd.print(msgvolt.getFloat());
    wait(1000);
      Serial.print("Battery Voltage: ")`;
   Serial.print(dadosenviados);
   Serial.println(" V");
}

void loop() {
}

[AWI]

@Walyson-Albuquerque-Machado a few things :

• the receive routine should be the only place where you receive and read the incoming messages. So skip the incomingmessage routine and add its functionality to receive.

• you don't need to 'request' anything as the node already sends messages all the time.

• savestate writes only byte (8 bit) values, so you need to decompose a float to bytes in order to save it. (best to use an 'union' for that)

Be aware that the gateway (node 0) receives the messages from all nodes connected. You need to make sure that that the incoming message is the one to display.

In summary, to receive messages : the receive routine is called automatically when a message is received. You read the message content (store in a global variable) , and display it.

[Walyson Albuquerque Machado]

Ok, I'm going to erase the void incomingMessage(const MyMessage &msgvolt) and the request(4, V_VOLTAGE, 10).
Also no savestate.

I tried to store in a global variable and display, but I didn't understand It, how do I read!?

void receive(const MyMessage &msgvolt) {
  if (msgvolt.type==V_VOLTAGE) {
    digitalWrite(msgvolt.sensor, msgvolt.getFloat());
  
 dadosenviados = msgvolt.getFloat();


Serial.println(msgvolt.getFloat());
Serial.println(dadosenviados);
Serial.println(msgvolt.data);
}

This is what I'm getting in the serial:

Node:

Battery Voltage: 8.68 V
RF24:stop listening
RF24:write register, reg=0, value=14
RF24:open writing pipe, recipient=0
RF24:write register, reg=10, value=0
RF24:write register, reg=16, value=0
RF24:send message to 0, len=12
RF24:flushTX
RF24:write register, reg=7, value=48
RF24:start listening
RF24:write register, reg=0, value=15
RF24:write register, reg=10, value=10
TSP:MSG:SEND 10-10-0-0 s=4,c=1,t=38,pt=7,l=5,sg=0,ft=0,st=ok:8.68
RF24:read message, len=12
RF24:write register, reg=7, value=64
TSP:MSG:READ 0-0-10 s=4,c=1,t=38,pt=7,l=5,sg=0:8.68
Battery Voltage: 8.69 V

Gateway:

10;4;1;0;38;8.68
0;255;3;0;9;TSP:MSG:READ 10-10-0 s=4,c=1,t=38,pt=7,l=5,sg=0:8.68
0;255;3;0;9;TSP:MSG:ACK msg
0;255;3;0;9;TSP:MSG:SEND 0-0-10-10 s=4,c=1,t=38,pt=7,l=5,sg=0,ft=0,st=ok:8.68
10;4;1;0;38;8.68