I am finishing building a new home and I have asked to make sure the roller shutter motors in all windows are prepared for KNX (i.e. there is a cable from each motor to a central rack). I now have to buy a KNX device to control the shutters (and potentially other devices). Which KNX interface/controller do you recommend that works well with Home Assistant? Thanks!
Hi! 
Normally every knx blind actuator should also work with HAs knx integration. Be sure it has a dedicated position status communication object (which they probably all have nowadays) and it fits your motors (230V, 24V, SMI, …)
If your motors are directly triggered (I don’t know the right term in english here) you could make use of devices with automatic travel time detection.
I have personally not installed my blinds yet, but I already bought the actuators for them, so I don’t have any practical experience with them yet. I had a look at the applications in ETS of various models and decided the ABB JRA/S series could fit my needs well. I liked the ability to set a time period after manual control falls back to automatic mode and their heating/cooling support function. They do not have the most sophisticated sun tracking options, but that is ok for me.
Thanks so much! I was completely lost but you just put me on the right path 
I found two models, one from the ABB series you recommended plus one from Schneider (my electrician recommends Schneider but he doesn’t really know what to buy, not an expert with home automation).
After I install one of these actuators, does Home Assistant speak directly to them? Or do I need an interface between the actuator and Home Assistant.
If anybody else has any other recommended hardware that plays nicely with Home Assistant, please let me know. Thanks!!
You will need a Knx Ip Interface or a Knx Ip Router. Then HA can connect to the bus via LAN.
I’d go for a Interface because is cheaper and easier to install. Nearly every Knx manufacturer has one in their portfolio. It’s nice when you can have multiple simultaneous connections to it (eg. many support 4) so you can eg run HA and ETS at the same time.
They are ~140€, maybe you can even get a used one for less.
Some use power from Knx bus, others PoE and some need an extra power supply - be sure to check before you buy.
If cause your Knx bus needs to be functional so the right cabling and power supply has to be in place.