Thanks a lot, It works!!!

Here my code updated

// Enable debug prints to serial monitor
//#define MY_DEBUG 

// Enable and select radio type attached
#define MY_RADIO_NRF24

//#define MY_NODE_ID 7

#include <MySensors.h>

#define BARO_CHILD 0
#define BAR_SENSOR_ANALOG_PIN 0

unsigned long SLEEP_TIME = 60000;

MyMessage pressureMsg(BARO_CHILD, V_PRESSURE);
void setup(){
  
}

void presentation() {
  sendSketchInfo("pressure Sensor", "1.0");
  present(BARO_CHILD, S_BARO);
}

void loop() {
    
  int lecture_adc = analogRead(BAR_SENSOR_ANALOG_PIN);
  float pression = ((lecture_adc*5/1024.0)-0.50)/1.7;
  Serial.println(pression);        
  send(pressureMsg.set(pression, 2));
        
  sleep(SLEEP_TIME);
}

correct, it makes sense. I will correct this error.
However Domoticz reads correctly the temperature and links correctly the CHILD ID's, so...

Sur,

my node controls two relays, one water pressure sensor and three DS18b20

/**
 code pour controle cave a vin, temp et pression
 */

// Enable debug prints to serial monitor
//#define MY_DEBUG

// Enable and select radio type attached
#define MY_RADIO_NRF24

// Enable repeater functionality for this node
#define MY_REPEATER_FEATURE

#define MY_NODE_ID 15
#include <SPI.h>
#include <MySensors.h>
#include <DallasTemperature.h>
#include <OneWire.h>

#define BARO_CHILD 0 //Child ID for pressure sensor
#define BAR_SENSOR_ANALOG_PIN 0 // pin for pressure sensor

#define COMPARE_TEMP 1 // Send temperature only if changed? 1 = Yes 0 = No

#define ONE_WIRE_BUS 5 // Pin where dallase sensor is connected 
#define MAX_ATTACHED_DS18B20 16
#define RELAY_PIN 3 //pin for first relay
#define NUMBER_OF_RELAYS 2
#define RELAY_ON 1  // GPIO value to write to turn on attached relay
#define RELAY_OFF 0 // GPIO value to write to turn off attached relay

OneWire oneWire(ONE_WIRE_BUS); // Setup a oneWire instance to communicate with any OneWire devices (not just Maxim/Dallas temperature ICs)
DallasTemperature sensors(&oneWire); // Pass the oneWire reference to Dallas Temperature. 
float lastTemperature[MAX_ATTACHED_DS18B20];
int numSensors=0;
bool receivedConfig = false;
bool metric = true;
float lastpression;
uint8_t DS_First_Child_ID = 4; //First Child-ID to be used by Dallas Bus
MyMessage pressureMsg(BARO_CHILD, V_PRESSURE);
MyMessage msg(0,V_TEMP);


void before()
{
    for (int sensor=1, pin=RELAY_PIN; sensor<=NUMBER_OF_RELAYS; sensor++, pin++) {
        // Then set relay pins in output mode
        pinMode(pin, OUTPUT);
        // Set relay to last known state (using eeprom storage)
        digitalWrite(pin, loadState(sensor)?RELAY_ON:RELAY_OFF);
    }
    
    // Startup up the OneWire library
  sensors.begin();
}

void setup()
{
   
// requestTemperatures() will not block current thread
  sensors.setWaitForConversion(false);
}

void presentation()
{
    // Send the sketch version information to the gateway and Controller
    sendSketchInfo("Buanderie node", "1.0");

    //present pressure sensor
    present(BARO_CHILD, S_BARO);

    for (int sensor=1, pin=RELAY_PIN; sensor<=NUMBER_OF_RELAYS; sensor++, pin++) {
        // Register all sensors to gw (they will be created as child devices)
        present(sensor, S_BINARY);
    }

    
// Fetch the number of attached temperature sensors  
  numSensors = sensors.getDeviceCount();

  // Present all sensors to controller
  for (int i=0; i<numSensors && i<MAX_ATTACHED_DS18B20; i++) {   
     present(i + DS_First_Child_ID, S_TEMP);
  }
}



void loop()
{
  //read water pressure
int lecture_adc = analogRead(BAR_SENSOR_ANALOG_PIN);
  float pression = ((lecture_adc*5/1024.0)-0.50)/1.7;
  if(pression != lastpression) { 
      send(pressureMsg.set(pression, 2));
  lastpression = pression;
  }
  
  
  // Fetch temperatures from Dallas sensors
  sensors.requestTemperatures();

  // query conversion time and sleep until conversion completed
  int16_t conversionTime = sensors.millisToWaitForConversion(sensors.getResolution());
  // sleep() call can be replaced by wait() call if node need to process incoming messages (or if node is repeater)
  sleep(conversionTime);

  // Read temperatures and send them to controller 
  for (int i=0; i<numSensors && i<MAX_ATTACHED_DS18B20; i++) {

    // Fetch and round temperature to one decimal
    float temperature = static_cast<float>(static_cast<int>((getControllerConfig().isMetric?sensors.getTempCByIndex(i):sensors.getTempFByIndex(i)) * 10.)) / 10.;

    // Only send data if temperature has changed and no error
    #if COMPARE_TEMP == 1
    if (lastTemperature[i] != temperature && temperature != -127.00 && temperature != 85.00) {
    #else
    if (temperature != -127.00 && temperature != 85.00) {
    #endif

      // Send in the new temperature
      send(msg.setSensor(i + DS_First_Child_ID).set(temperature,1));
      // Save new temperatures for next compare
      lastTemperature[i]=temperature;
    }
  }
}

void receive(const MyMessage &message)
{
    // We only expect one type of message from controller. But we better check anyway.
    if (message.type==V_STATUS) {
        // Change relay state
        digitalWrite(message.sensor-1+RELAY_PIN, message.getBool()?RELAY_ON:RELAY_OFF);
        // Store state in eeprom
        saveState(message.sensor, message.getBool());
        // Write some debug info
        Serial.print("Incoming change for sensor:");
        Serial.print(message.sensor);
        Serial.print(", New status: ");
        Serial.println(message.getBool());
    }
}

perfect it works great. I started my temperature sensor at CHILD ID 4 and let relays from 1 to 2. I had to add also "DS_First_Child_ID" in the sent message to gateway.
thanks

ok thanks a lot I will try this night

hello.
I am building a node with several kind of sensors and two relays.
My sensors use CHILD ID from 0 to 3. I would like to start child ID of relay from 4.
How I can't do that with this sketch?
I guess I have to change this part of sketch :
"for (int sensor=1, pin=RELAY_PIN; sensor<=NUMBER_OF_RELAYS; sensor++, pin++) {
// Register all sensors to gw (they will be created as child devices)
present(sensor, S_BINARY);"

correct?

thanks

Thanks a lot, It works!!!

Here my code updated

// Enable debug prints to serial monitor
//#define MY_DEBUG 

// Enable and select radio type attached
#define MY_RADIO_NRF24

//#define MY_NODE_ID 7

#include <MySensors.h>

#define BARO_CHILD 0
#define BAR_SENSOR_ANALOG_PIN 0

unsigned long SLEEP_TIME = 60000;

MyMessage pressureMsg(BARO_CHILD, V_PRESSURE);
void setup(){
  
}

void presentation() {
  sendSketchInfo("pressure Sensor", "1.0");
  present(BARO_CHILD, S_BARO);
}

void loop() {
    
  int lecture_adc = analogRead(BAR_SENSOR_ANALOG_PIN);
  float pression = ((lecture_adc*5/1024.0)-0.50)/1.7;
  Serial.println(pression);        
  send(pressureMsg.set(pression, 2));
        
  sleep(SLEEP_TIME);
}

Makes sense! My value didn't change over time
But what means this ligne

#define BAR_SENSOR_ANALOG_PIN 0

I guessed it was to declare AnalogRead on pin 0?

Thanks for your answer.

Exactly, I don't get the same value

Here my full debug

0 MCO:BGN:INIT NODE,CP=RNNNA--,VER=2.1.1
3 TSM:INIT
4 TSF:WUR:MS=0
11 TSM:INIT:TSP OK
12 TSM:INIT:STATID=7
14 TSF:SID:OK,ID=7
16 TSM:FPAR
35 TSF:MSG:SEND,7-7-255-255,s=255,c=3,t=7,pt=0,l=0,sg=0,ft=0,st=OK:
2042 !TSM:FPAR:NO REPLY
2044 TSM:FPAR
2063 TSF:MSG:SEND,7-7-255-255,s=255,c=3,t=7,pt=0,l=0,sg=0,ft=0,st=OK:
2071 TSF:MSG:READ,0-0-7,s=255,c=3,t=8,pt=1,l=1,sg=0:0
2076 TSF:MSG:FPAR OK,ID=0,D=1
4071 TSM:FPAR:OK
4072 TSM:ID
4073 TSM:ID:OK
4075 TSM:UPL
4077 TSF:MSG:SEND,7-7-0-0,s=255,c=3,t=24,pt=1,l=1,sg=0,ft=0,st=OK:1
4083 TSF:MSG:READ,0-0-7,s=255,c=3,t=25,pt=1,l=1,sg=0:1
4088 TSF:MSG:PONG RECV,HP=1
4091 TSM:UPL:OK
4092 TSM:READY:ID=7,PAR=0,DIS=1
4097 TSF:MSG:SEND,7-7-0-0,s=255,c=3,t=15,pt=6,l=2,sg=0,ft=0,st=OK:0100
4104 TSF:MSG:READ,0-0-7,s=255,c=3,t=15,pt=6,l=2,sg=0:0100
4110 TSF:MSG:SEND,7-7-0-0,s=255,c=0,t=17,pt=0,l=5,sg=0,ft=0,st=OK:2.1.1
4118 TSF:MSG:SEND,7-7-0-0,s=255,c=3,t=6,pt=1,l=1,sg=0,ft=0,st=OK:0
4128 TSF:MSG:READ,0-0-7,s=255,c=3,t=6,pt=0,l=1,sg=0:M
4134 TSF:MSG:SEND,7-7-0-0,s=255,c=3,t=11,pt=0,l=15,sg=0,ft=0,st=OK:pressure Sensor
4144 TSF:MSG:SEND,7-7-0-0,s=255,c=3,t=12,pt=0,l=3,sg=0,ft=0,st=OK:1.0
4151 TSF:MSG:SEND,7-7-0-0,s=0,c=0,t=8,pt=0,l=0,sg=0,ft=0,st=OK:
4157 MCO:REG:REQ
4160 TSF:MSG:SEND,7-7-0-0,s=255,c=3,t=26,pt=1,l=1,sg=0,ft=0,st=OK:2
4166 TSF:MSG:READ,0-0-7,s=255,c=3,t=27,pt=1,l=1,sg=0:1
4171 MCO:PIM:NODE REG=1
4173 MCO:BGN:STP
4175 MCO:BGN:INIT OK,TSP=1
-0.29
4178 TSF:MSG:SEND,7-7-0-0,s=0,c=1,t=4,pt=7,l=5,sg=0,ft=0,st=OK:-0.29
4186 MCO:SLP:MS=60000,SMS=0,I1=255,M1=255,I2=255,M2=255
4191 MCO:SLP:TPD
4192 MCO:SLP:WUP=-1
-0.29
4196 TSF:MSG:SEND,7-7-0-0,s=0,c=1,t=4,pt=7,l=5,sg=0,ft=0,st=OK:-0.29
4202 MCO:SLP:MS=60000,SMS=0,I1=255,M1=255,I2=255,M2=255
4207 MCO:SLP:TPD```

Hello,

I need your help to write my first "My sensor" sketch.
I use this 5V sensor (link below) and pro-mini arduino to mesure water pressure inside my home water pipe.
https://fr.aliexpress.com/item/0-0-5-Mpa-Water-Gas-Pressure-Sensor-G1-4-DC-5V-Air-Compressor-Pressure-Transmitter/32660132491.html?spm=a2g0s.9042311.0.0.KxZ6lv

I used this simple sketch to read water pressure in Bar. I can read a pressure around 2.20 Bar

void setup() {
  Serial.begin(9600);
}

void loop() {
int lecture_adc;
float pression;

lecture_adc = analogRead(A0);
Serial.print("Sensor Value: ");
Serial.println(lecture_adc);
pression = (((lecture_adc*5/1024.0)-0.52)/1.7); //read pressure in Bar, remove 1.7 to read Voltage, divide 0.17 to read in  MPa        
Serial.print("Pression: ");
Serial.println(pression);

delay(1000);

Now, I tried to monitore my water pressure with my sensor and domoticz, that's why I wrote this sketch

// Enable debug prints to serial monitor
#define MY_DEBUG 

// Enable and select radio type attached
#define MY_RADIO_NRF24

#define MY_NODE_ID 7

#include <MySensors.h>

#define BARO_CHILD 0
#define BAR_SENSOR_ANALOG_PIN 0

unsigned long SLEEP_TIME = 60000;

MyMessage pressureMsg(BARO_CHILD, V_PRESSURE);
void setup(){
  
}

void presentation() {
  sendSketchInfo("pressure Sensor", "1.0");
  present(BARO_CHILD, S_BARO);
}

void loop() {
  int lecture_adc;
  float pression;

  lecture_adc = BAR_SENSOR_ANALOG_PIN;
  pression = ((lecture_adc*5/1024.0)-0.52)/1.7;
  Serial.println(pression);        
  send(pressureMsg.set(pression, 2));
        
  sleep(SLEEP_TIME);
}

But with this code, my node send as value -0.21 (check in DEBUG). I don't understand why.
Could you help me to understand what is wrong?

Thanks