Help work out correct MQTT message to activate relay

[ahmedadelhosni]

Can you please post your GW sketch ?

Check this also.
http://forum.mysensors.org/topic/2378/how-can-i-set-the-payload-for-mqtt-v1-6

Another note regarding the above link. Some replies are talking about a bug which was fixed. But in all cases check the first replies concerning setting the message structure.

[TommySharp]

As far as I know I am just using the default MySensors relay sketch with 1 relay.

// Example sketch showing how to control physical relays. 
// This example will remember relay state even after power failure.

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

#define RELAY_1  6  // Arduino Digital I/O pin number for first relay (second on pin+1 etc)
#define NUMBER_OF_RELAYS 1 // Total number of attached relays
#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

MySensor gw;

void setup()  
{   
  // Initialize library and add callback for incoming messages
  gw.begin(incomingMessage, AUTO, true);
  // Send the sketch version information to the gateway and Controller
  gw.sendSketchInfo("Relay 1.0");

  // Fetch relay status
  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)
    gw.present(sensor, S_LIGHT);
    // Then set relay pins in output mode
    pinMode(pin, OUTPUT);   
    // Set relay to last known state (using eeprom storage) 
    digitalWrite(pin, gw.loadState(sensor)?RELAY_ON:RELAY_OFF);
  }
}


void loop() 
{
  // Alway process incoming messages whenever possible
  gw.process();
}

void incomingMessage(const MyMessage &message) {
  // We only expect one type of message from controller. But we better check anyway.
  if (message.type==V_LIGHT) {
     // Change relay state
     digitalWrite(message.sensor-1+RELAY_1, message.getBool()?RELAY_ON:RELAY_OFF);
     // Store state in eeprom
     gw.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());
   } 
}

[TommySharp]

@ahmedadelhosni

Ahhh by GW sketch I guess you mean gateway sketch? I set that up well over a year ago and I actually wouldn't even have a clue where the original sketch is... My temp/humidity sensors have been working perfectly for over a year now. So just diving back into the arduino stuff to see if I can get the relay going.

I'm even using a different PC to compile and upload the sketches so I might not even have the original GW sketch....

[ahmedadelhosni]

@TommySharp Yeah I mean the gateway.

You say your gateway is running for a year now, but now you want to use MQTT so you have to set this MQTT gateway. I am not familiar with MYsensor library 1.5 or previous versions. I am using the development branch ( https://github.com/mysensors/Arduino )
It has a sketch for setting MQTT gateway and you can test sending a payload data using mosquitto as explained in my first link in the previous reply. Also there is a new sketch for relayactuator example.

It works okay and I have tested it.

[TommySharp]

@ahmedadelhosni
Yes my gateway is the MQTT gateway and it has been running for well over a year. It happily posts temp/humidity which my OpenHAB server subscribes to and reads in the sensor readings.

I just need to work out now how to activate a relay :-)

[martinhjelmare]

@TommySharp

Hi!

According to the mqtt gateway sketch in 1.5.3, topic structure is:

Topicprefix/node_id/child_id/v_type

Mysensors payload is mqtt payload.

[TommySharp]

So when my relay sensor announces itself to the gateway below.... Does it announce the child ID anywhere so I can be sure I'm using the right one?

send: 24-24-0-0 s=255,c=3,t=11,pt=0,l=5,st=ok:Relay
send: 24-24-0-0 s=255,c=3,t=12,pt=0,l=3,st=ok:1.0
send: 24-24-0-0 s=1,c=0,t=3,pt=0,l=5,st=ok:1.4.1

[martinhjelmare]

The last line shows s=1, so child id is 1.

Read this post for details on topic structure:
http://forum.mysensors.org/topic/303/mqtt-broker-gateway/17

Also read the text at the top of the mqtt gateway sketch for more info.

I think you should test with this topic:
prefix/24/1/V_LIGHT

Replace prefix with your set topic prefix.

You can set payload with the -m option if you're using mosquitto.

[martinhjelmare]

Be aware though, that the mqtt broker gateway sketch will me removed in the next release, so if you want the best support I would think about changing to the mqtt client gateway. This is currently only available in the dev branch at github, but there is a sticky guide in the forum, on how to set it up.

[TommySharp]

Awesome! I'd much rather use a client gateway so might just hold off until the next release of MySensors and then use the MQTT Client Gateway.