Saturday, 14 October 2017

Update on DFK .AS camera problems with USB 3

It has been known for some time that DFK astronomy cameras have a problem with USB 3. Specifically in YUYV format the camera streams video but the controls for exposure, gain etc do not work, where they work fine in USB 2. This is a problem with Windows and Linux. On Nicola's website  where AstroDMx Capture for Linux can be downloaded, she gives a hack that routes the data from the USB ports through the EHCI controller, instead of the xHCI controller. On newer laptops that often have USB 3 and USB 2 ports, the USB 2 ports are often also routed through the xHCI controller, which means that the DFK also doesn't work correctly with the USB 3 or the USB 2 ports on these machines.

Nicola's hack will also work on these laptops, causing both USB 3 (which knows that the DFK is a USB 2 device) and the USB 2 ports to work correctly with the DFK. However, on the latest laptops, which only have xHCI controllers, the hack doesn't work.
However, none of this matters, because even without the hack, the Bayer mode works correctly and either Bayer or RGB SER or AVI files can be saved. The simplest solution is to select the Bayer mode when connecting the DFK camera to AstroDMx Capture for Linux.