Hi,
When using my Atik color filter wheel on my Raspberry Pi 3, I see regularly warnings about the driver not being able to write to or read from the wheel. Sometimes it helps to disconnect and reconnect the INDI driver but more often I need to turn the wheel off and back on to get everything working again. Connecting the wheel via a powered USB hub to the RPi3 doesn't help. I have attached the output of running indiserver -vvv. I am running the latest version of Raspbian and compile INDI from the latest source code. I have also tried several versions of indi_atik_wheel: 1.6, 1.8, 1.11 and 1.13. They all have the same problem. When I connect the wheel to my PC with kubuntu (latest vesion, INDI from source, version 1.13 of the driver), there is no problem. So I guess that this is a Raspbian/RPi3 related problem. Does anyone know the cause?
Regards,
Camiel

It happened to me when using USB hub. Direct USB connection worked properly. However it is not your case because it looks like the problem persists in both cases.
What user do you run indiserver as? If it is not root make sure that a user can access FW device (normally it's enough to add user to dialout group). Also play a bit with your USB cables and test a few of them to check if it is not a wiring problem. In any case make sure that the FW is powered with stable 12V supply. Let us know of the results.

Okay, that put me on the right track I think.
The USB cable is fine since I use it to connect to my PC too (via a powered USB hub) and found no problems. This also excludes the power supply of the wheel too. (It also works fine using the Atik software under windows.)
It turns out , that when the wheel is the only device connected to my RPi I don't get the error messages.
My solution is to connect all other device via a powered USB hub to my RPi. So far the wheel is working properly. When I connect it via the USB hub, the errors return. This confirms what you found. It does seem strange to me though since the wheel does work correctly with my PC and a hub. Maybe this hints at a problem in the Raspian kernel?
Regards,
Camiel

I have just tested it again and I can confirm that Atik Filter Wheel does not work over usb hub. It works ok when connected directly to Raspberry Pi (v3).
It is must be some kind of hardware problem because it is not an issue when using Banana Pi M3 i.e. FW works ok over a powered hub.

We observed the same here: RPi + hub does not work, while RPi direct works, PC + same hub works fine too… I also had the same issue with one special USB stick some time ago.

I've just bought a EFW2. Does the INDI server support direct connection without further drivers (The INDILIB.ORG site suggest so). But The INDI Server (using RPI install) doesn't have ATIK or EFW2 in the drop down devices? What is everyone using?

You need to download them from Cloudmakers