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jpraus / arduino-opentherm

Arduino library and hardware shield to send and receive data from Opentherm devices
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Understanding examples #17

Closed phenotypic closed 4 years ago

phenotypic commented 4 years ago

Hey there, I'm having some difficulty understanding exactly how to use the library from the examples as they are quite limited. I have a couple of questions that should hopefully clarify some things for me:

  1. Does the boiler need to be contacted every time in a loop, or can contact be event-based (e.g. when I want to change the temperature, change it then, rather than constantly setting it in each loop)
  2. How can I set values? (e.g. the target temperature or the target central heating state)
  3. How can I read values? (e.g. the upper and lower bound for heating, and the current boiler temperature)

I would really appreciate it if you could supply some examples as I'm having trouble back-calculating from the actual library source. Thanks!

jpraus commented 4 years ago

I would recommend you reading the OpenTherm specification https://github.com/jpraus/arduino-opentherm/blob/master/doc/Opentherm%20Protocol%20v2-2.pdf. It will explain everything. Shortly:

  1. Yes you need to contact boiler every 1 second a keep-alive signal.
  2. You send setpoint temperature command
  3. You send a command to read a certain value

For 2. and 3. you need to check the specification to find the appropriate command.

jpraus commented 4 years ago

For the values you don't need to parse the upper and lower bound yourself. You can use utility functions on OpenthermData see https://github.com/jpraus/arduino-opentherm/blob/master/src/opentherm.h: