How to deal with a request for information from controller?

[marcusvdt]

@barduino
I'll post it for you tomorrow, but my main concern is to keep the things as much as possible conform the design of this protocol. It's because I don't want that my future version upgrades turn into a nightmare.
That's why I wanted someone from mysensors staff to tell me about this.

IMHO, there are many legitimate reasons for a controller needing to request information to sensors.
In my case, I have light actuators that I designed to work either from a standard wall switch or by commands sent from the controller or by claps. I find the need to request information from the actuator node because sometimes the computer where the controller is running could be unreachable. Also some times the radio can fail. And sometimes I could just want to make sure the current status shown on my controller matches the current status of the actual node. Also, like you said, this allows node to request information from other nodes.

[hek]

@marcusvdt

You are right, the idea (with REQ comands) was to let node requests response with a SET-command back to the requester. The examples does not have this functionality implemented. And as you might have suspected it was mainly thought to be used between sensors. But I haven't really had any use for it myself in my setup (easier to just push messages that do the request-setup).

But there are use-cases, especially for sleeping nodes that can wake up and request data and go back to sleep when they have received their response.

[gonzalonal]

Hi, is there any way in which I can identify the message type in my incomingMessage function?

void incomingMessage(const MyMessage &message)
{
	**//I need to identify firstly the command type (REQ, SET,PRESENTATION,etc)**
	// if(message.type == C_REQ)
if (message.type == V_LIGHT) // this would be the subtype
	{ 
		if ((message.sensor - StartingChildID)  < noZones)
		{   
			Relays[message.sensor - StartingChildID].relayState = message.getBool();
		}
	}
}

I need to be able to request values at will from nodes. Mainly for debug purposes.

Thanks. Regards

[hek]

mGetCommand(message)

[gonzalonal]

Shouldn't be nice to have this feature directly emebebed in Mysensors library (as the ack request feature)?
I mean, if I send a status request for a sensor through the controller, to ahve the library automaticcaly answer this type of messages.

[alfredocdmiranda]

@hek Why there is no method getCommand() in MyMessage object like isAck()?

[hek]

@alfredocdmiranda

good question. :)

[alfredocdmiranda]

Is there any chance to create it for next version?

[hek]

@alfredocdmiranda

I'll put it on the list.

[Kumar Ratnanabh]

@marcusvdt said:

lightMsg

Hello
I wanted the same functionality and during forum found your post.
Can you please post your code as attached code block has missing functions e.g lightMsg.set... SetLightState(..

Thanks
Ratnanabh

[rollercontainer]

I would like to share my sketch for 2.0.0-beta. Its a node with two relays and the ability to read the status from mqtt.

// Relais Node for MySensors 2.0.0-beta

// I am using the filename and compile date for sktech announcements:
#include <string.h>
// Strip the path info from __FILE__ 
// For Windows use '\\' instead of '/'.
#define __FILENAME__ (strrchr(__FILE__, '\\') ? strrchr(__FILE__, '\\') + 1 : __FILE__)
 
// #define MY_DEBUG
#define MY_RADIO_NRF24
#define SKETCH_NAME __FILENAME__
#define SKETCH_DATE __DATE__
#define MY_NODE_ID 2
#define MY_PARENT_NODE_ID 0
#define MY_REPEATER_FEATURE false

#include <SPI.h>
#include <MySensor.h>

#define RELAY_1  3  // Arduino Digital I/O pin number for first relay (second on pin+1 etc)
#define NUMBER_OF_RELAYS 2 // Total number of attached relays
#define RELAY_ON 0  // GPIO value to write to turn on attached relay
#define RELAY_OFF 1 // GPIO value to write to turn off attached relay

void before() { 
  for (int sensor=1, pin=RELAY_1; 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);
  }
}

void setup() {
  
}

void presentation()  
{   
  // Send the sketch version information to the gateway and Controller
  sendSketchInfo(SKETCH_NAME, SKETCH_DATE);

  for (int sensor=1, pin=RELAY_1; sensor<=NUMBER_OF_RELAYS;sensor++, pin++) {
    // Register all sensors to gw (they will be created as child devices)
    present(sensor, S_LIGHT);
  }
}

void loop() 
{
  
}

void receive(const MyMessage &message) {
int msgcmd = mGetCommand(message);
  
  // Verify its a switch command (V_LIGHT)
  if (message.type==V_LIGHT) {
    // Command type 1 is a set command 
     if (msgcmd==1){
       // Change relay state
       digitalWrite(message.sensor-1+RELAY_1, message.getBool()?RELAY_ON:RELAY_OFF);
       // Store state in eeprom
       saveState(message.sensor, message.getBool());
     }
   // Command type 2 is a request for the sensor state
   if (msgcmd==2){
       // construct message body with requested sensor-id and type V_LIGHT (= switch) 
       MyMessage msg(message.sensor,V_LIGHT);
       // Example: requested sensor is 2 (message.sensor). 
       // The programm reads the digital pin 4, calculated by 2 (sensor) - 1 (static) + 3 (first relay pin)
       // after that, the reading is compared to the RELAY_ON value (might be invers logic, regarding to your relais schematic)
       // if it is matching, the payload is set to 1, otherwise its set to 0
       send(msg.set(digitalRead(message.sensor-1+RELAY_1) == RELAY_ON ? 1 : 0));
    }
  }
}

and here are the lines in my openhab2 items.item:

Switch node2_sw1   "N2SW1"    (all,node2)    { mqtt=">[mosquitto:mysensors-in/2/1/1/0/2:command:ON:1],>[mosquitto:mysensors-in/2/1/1/0/2:command:OFF:0],<[mosquitto:mysensors-out/2/1/2/0/2:state:default]" }
Switch node2_sw2   "N2SW2"    (all,node2)    { mqtt=">[mosquitto:mysensors-in/2/2/1/0/2:command:ON:1],>[mosquitto:mysensors-in/2/2/1/0/2:command:OFF:0],<[mosquitto:mysensors-out/2/2/2/0/2:state:default]" }

I would like to repeat: Its for the last versions of mysensors and openhab2. Notice the absence of any "gw." and the different structure in the mqtt strings !

Can someone tell me, if it is a problem to redefine the "MyMessage msg(message.sensor,V_LIGHT); " every time a request is done? I am not sure.

Greetings

[rollercontainer]

I dont see openHAB requesting any state, so maybe its a better idea to read the state of the output pin immediately after setting the relay and publish this and bind it to a control lamp. If this isnt toggling, the command wasnt received.