View Full Version : Heatmiser thermostat - Anyone written interface code?

May 26th, 2011, 03:45 PM
Hi there,
before I set to and try and sort this for myself, has anyone written any code to interface directly with this thermostat over RS485 to save me a heap of time and effort?

I have the link working fine with their demo software so I know the hardware is ok, I'm just working out where to start getting it to work with girder and netremote so I can display / control / interface with the thermostats from a central / remote location.

Link to product:
I specifically have the PRT-N version, but they all follow the same protocol.

The protocol is available here:

With thanks

December 16th, 2011, 10:58 AM
in case anyone is interested, I got this up and running.
The code could probably be minimised but it is fairly well commented.
It allows me to connect to one or more 12V heatmiser network thermostats and get any of the parameters (such as setpoint, actual temp etc) and also set the setpoint, or turn it on/off.
I've got a basic link to netremote to show the data.
It is possible (although i havn't finished it yet) to program the thermostats by sending a command (for instance to alter the settings between summer and winter).
I got very confused what the best way is to 'poll' something on a regular basis, and decided to use a treescript simple timer to fire a command off every second. There is probably a better way to do this, but this works.
See attached what I have to date 6347 but it needs more work.