rjdekker
commented
5 years ago Thank you for your interest CanuckianOz!
Unfortunately, it is not possible to write to the statusRoomtemp topic. For this the code would need to be adapted, but more importantly, I do not know if and how it would be possible to send data from an external temperature sensor to the MHIs. I decoded the serial protocol using a commercially available WiFi module and it did not have such functionality.
It might still be possible but I am clueless to what bitfields in the data frames allow writing external temperature values to. A few zero bitfields do not change and might be candidates. So far, however, the communication protocol has been anything but straightforward so I’m not expecting a simple solution. I remember that I did try to write to the same bitfield that contains the information from the internal sensor, but if I remember correctly, it didn’t respond. For most write operations a specific bit needs to be set for the duration of 24 data frames and I was unable to find it, if it even exists.
With kind regards,
Rob
Hi Rob,
Love the project and many thanks for putting in the effort to develop and document!
I realise that you no longer have a system to test on and improve this, but I was wondering if it's possible to write values to statusRoomtemp using your code? IE Zigbee temperature values from various rooms.
The main reason I want to use this is as we have an MHI ducted air conditioning system with zones, but only one temperature sensor so the system can cool individual rooms but only sees the central thermostat temperature. Would be good to know if this is possible before I dive into Arduino and buy the components! I'm new to Arduino but have been using RPi for some time.
Cheers, CanuckianOz