Requesting a sensor value from a different node?

[BulldogLowell]

@sansespere said:

@andyuno

Hey, no problem - the LCD I'm using is this one in a 16x2 format.

Haven't had much of a chance to work on it yet since first getting it working with Hek's advice above but this is what I have so far. Standard disclaimer though, I'm new to this whole coding and electronics stuff so there may be a better way of doing it.

To start with, in the sketch of the sensor that has the information you want to display, find where it's sending the data to the gateway, and get it to send to the node that has the LCD at the same time. EG:

gw.sendVariable(CHILD_ID_TEMP, V_TEMP, temperatureB, 1); //standard line sending data to the gateway
gw.sendVariable(MONITOR_STATION,CHILD_ID_TEMP, V_TEMP, temperatureB, 1); //new line that needs to be created, where MONITOR_STATION is defined as the radioID of the node with the LCD

and below is the testing sketch I wrote to receive and display the messages:

 #include <SPI.h>
 #include <EEPROM.h>  
 #include <RF24.h>
 #include <Sensor.h>  
 #include <Time.h>  
 #include <Wire.h>  
 #include <LiquidCrystal_I2C.h>

 Sensor gw;
 #define CHILD_ID 10
 
 LiquidCrystal_I2C lcd(0x27, 2, 1, 0, 4, 5, 6, 7, 3, POSITIVE);  // Set the LCD I2C address
 float temp = 0; //for storing temperature values
 float hum = 0; //for storing humidity values
 
 void setup()  
 {  
   gw.begin();
   // Send the sketch version information to the gateway and Controller
   gw.sendSketchInfo("LCD", "1.0");
 
   // Register any sensortype. This example we just create a motion sensor.
   gw.sendSensorPresentation(CHILD_ID, S_MOTION);
 
   lcd.begin(16,2);   //Specify LCD size
   lcd.backlight();   
 }

 void loop()     
 {     
   int LoopCount = 0; // LoopCount is there to make sure that we dont get stuck in a never ending loop of processing messages - not sure if this could ever even happen, but just to be safe
 
   while(gw.messageAvailable()==true && LoopCount < 10){ //while there are messages in the queue and we havent processed more than 10 since entering the loop
       message_s  message = gw.getMessage(); //get the message
       if (message.header.type == 0){  //check the type of message it is - temperature, humidity, etc. as per Variable Types defined in http://www.mysensors.org/build/sensor_api
       temp = atof(message.data); //if it's a temp type, get the data and convert it to float
       }
       if (message.header.type == 1){
       hum =  atof(message.data); //if it's a humidity type, get the data and convert it to float
       }  
       LoopCount++;  //increment the loop counter
   }
  
   if (LoopCount >= 1){ //Check if we need to update the LCD
    UpdateLCD(); 
   }
   
   //serial prints for troubleshooting
   Serial.print("Temp: ");
   Serial.println(temp);
   Serial.print("Hum: ");
   Serial.println(hum);
   Serial.println("Waiting");

   delay(10000);   //take a short break  
 }

 void UpdateLCD() { //LCD output
   lcd.clear();
   lcd.print("Temp:");
   lcd.print(temp,1);
   lcd.print("C"); 
   lcd.setCursor(0,1);
   lcd.print("Humi:");
   lcd.print(hum,1);
   lcd.print("%"); 

 }

and you end up with something like this.....

showing data for a sensor I have sitting outside.

Still a lot of work to do to get it right - there are other things I want to display, using scrolling messages to cycling messages, etc, but this is just a basic proof of concept.

nice work.

for your next revision we can show you how to do this without holding in the while loop or using delays.

terrific!!!!! :) I like LCD's :)

[sansespere]

Ahhh ok - so something more like this:

#include <SPI.h>
#include <EEPROM.h>  
#include <RF24.h>
#include <Sensor.h>  
#include <Time.h>  
#include <Wire.h>  
#include <LiquidCrystal_I2C.h>

Sensor gw;
#define CHILD_ID 1

LiquidCrystal_I2C lcd(0x27, 2, 1, 0, 4, 5, 6, 7, 3, POSITIVE);  // Set the LCD I2C address
float temp = 0; //for storing temperature values
float hum = 0; //for storing humidity values

void setup()  
{  
  gw.begin();
  // Send the sketch version information to the gateway and Controller
  gw.sendSketchInfo("LCD", "1.0");

  // Register any sensortype. This example we just create a motion sensor.
 gw.sendSensorPresentation(CHILD_ID, S_MOTION);

  lcd.begin(16,2);   //Specify LCD size
  lcd.backlight();   
}

void loop()     
{     
    message_s  message = gw.waitForMessage(); //wait for a message to process

    //check the type of message it is - temperature, humidity, etc. as per Variable Types defined in http://www.mysensors.org/build/sensor_api
    if (message.header.type == 0){  
      temp = atof(message.data); //if it's a temp type, get the data and convert it to float
    }
    else if (message.header.type == 1){
      hum =  atof(message.data); //if it's a humidity type, get the data and convert it to float
    }  
    else {
      Serial.print("Unknow Message Type");
    } 

  //serial prints for troubleshooting
  Serial.print("Temp: ");
  Serial.println(temp);
  Serial.print("Hum: ");
  Serial.println(hum);
  UpdateLCD(); 
  Serial.println("Waiting");
}

void UpdateLCD() { //LCD output
  lcd.clear();
  lcd.print("Temp:");
  lcd.print(temp,1);
  lcd.print("C"); 
  lcd.setCursor(0,1);
  lcd.print("Humi:");
  lcd.print(hum,1);
  lcd.print("%"); 

}

[andyuno]

@sansespere.. Nice work, I don't think I would've got most of that, now that should give me something to work from thanks.

[jendrush]

If someone have this converted to 1.4 version of library please post it.

[kwest]

If someone have this converted to 1.4 version of library please post it.

Have node №2 child 1 - temp sensor.
For example: how to ask the node 2 child 1 value from node №10?

[kwest]

This post is deleted!

[andriej]

Anyone?

@sansespere

[franklin216]

I've just found this thread, which describes the Convertion from 1.3 to 1.4:

http://forum.mysensors.org/topic/172/convert-sketch-from-1-3-to-1-4

I think, the following would do the trick, i will try it, when i am home this evenening:

// process incoming messages (like config from server) <-- insert line
gw.process(); <-- insert line
gw.sendVariable(MONITOR_STATION, CHILD_ID, V_TEMP, temperature, 1); change to --> gw.send(msg.setSensor(CHILD).set(temperature,1).setDestination(MONITOR_STATION)); // send float with one decimal point

[AWI]

I would imagine the "royal" way of getting sensor values is requesting them from the controller. In this case the sensor to be read does not need to bother about sending the values to all of the nodes and waking up is not an issue.

[Lawrence Helm]

did anyone convert this succesfully? I'm having some problems, this would make a great example build :) I looked at other ones like "node to node " but something simple like this would be great to start building from..