After testing the Daikin binding with my KKRP01A interface for a Ururu Sarara and looking at the source code for the binding I can confirm the binding is not compatible with these old wired controllers because the API endpoints are missing, even though it is possible to add a Thing all the channels show null values.
I found a fairly simple plugin for Domoticz that we can port ( Plugin for the Daikin Airconditioning (KKRP01A) - Domoticz )that shows which urls to use with this device and how to parse the responses.
http://daikin-ip/param.csv results in a string like:
OK. ON. HEAT. 21. FA. OFF. 22,5. OFF/OFF. ENA. ---. NOR.NOR.NOR.NOR. hostname. HEAT.21.21.21.FA. user. -3,0. 24. -. -. -. 1.
The interesting fields are
Status, Power, Mode, Setpoint, Fan, Swing, IndoorTemp, ?, ?, ?, ?, ?, ?, ?, hostname, ?, ?, ?, ?, username, OutDoorTemp, Humidity, ?, ?, ?
Changing parameters is done by sending a POST request to /index.htm with a plain text string like
[daikin] Support the BRP1B61 (aka Airbase) controller (#5910) · openhab/openhab2-addons@0ce6ddf · GitHub seems to be the commit that extended the binding with the ability to select multiple types of Daikin controllers, I will try to study this and make another extension for the KKRP01A if nobody is already working on it.
I’m not much of a java coder so it will take a while.