how to get data from controller?

[vga]

Hi,
is it possible that my sensor can call a value from the controller?
Scenario:
Flow Sensor sends the total liter to the controller, after rebooting the sensor total liters will be 0 again. So the idea is to get the last value from the controller at startup.
I haven´t find anything like this. Is there a function?

[AWI]

@vga You can with the gw.request function. Many of the controllers seem to have in not implemented (eg. Domoticz). For your scenario it would be a good solution to store the values in EEPROM (gw.saveState() (be aware that it only takes byte values

[alexsh1]

@AWI Are you sure about Domoticz? I am sure that a pulse meter node is requesting value from Domoticz every time it powers up and it is working.

// Fetch last known pulse count value from gw
  gw.request(CHILD_ID, V_VAR1);
  
  attachInterrupt(INTERRUPT, onPulse, RISING);
  lastSend=lastPulse=millis();

[AWI]

@alexsh1 you van get data from some specific variables, text and switches, but not for all sensors.

[alexsh1]

@vga What's your controller please?

@AWI It covers most of the things, no? Electricity pulse meter and water pulse meter. I have not come up with another example when gw.request may be applied.

[AWI]

@alexsh1 you can use special variables to store and retrieve values. These are not available in the Domoticz interface.
As far as I know only switches, text and a very domoticz specific custom value can be retrieved. You can find some discussion on the Domoticz forum.

[alexsh1]

@AWI yes I spoke to Rob about it some time ago. V_VAR is good enough for my needs. I just do not see why one would want more