Following up on the above.
I have tried using indiserver on my raspberry Pi 3. Using the latest snap shot.
When I plug the USB cable from the EFW straight into my pi the electric shock symbol (low voltage appears) on the pi screen,
while the filter wheel is homeing back to its position.
It rotates nicely.
indiserver -v indi_asi_wheel indi_simulator_ccd
2016-12-23T21:59:31: startup: indiserver -v indi_asi_wheel indi_simulator_ccd
2016-12-23T21:59:31: Driver indi_asi_wheel: pid=1497 rfd=3 wfd=6 efd=7
2016-12-23T21:59:31: Driver indi_simulator_ccd: pid=1498 rfd=4 wfd=9 efd=10
2016-12-23T21:59:31: listening to port 7624 on fd 5
2016-12-23T21:59:31: Driver indi_simulator_ccd: snooping on Telescope Simulator.EQUATORIAL_EOD_COORD
2016-12-23T21:59:31: Driver indi_simulator_ccd: snooping on Telescope Simulator.TELESCOPE_INFO
2016-12-23T21:59:31: Driver indi_simulator_ccd: snooping on CCD Simulator.FILTER_SLOT
2016-12-23T21:59:31: Driver indi_simulator_ccd: snooping on CCD Simulator.FILTER_NAME
2016-12-23T21:59:31: Driver indi_simulator_ccd: snooping on SQM.SKY_QUALITY
2016-12-23T21:59:31: Driver indi_simulator_ccd: snooping on Telescope Simulator.EQUATORIAL_PE
2016-12-23T21:59:31: Driver indi_simulator_ccd: snooping on Focuser Simulator.FWHM
2016-12-23T21:59:34: Client 0: new arrival from 192.168.1.1:55494 - welcome!
2016-12-23T22:00:40: Client 0: read EOF
2016-12-23T22:00:40: Client 0: shut down complete - bye!
I then tried kstars on my desktop and connected to the pi indiserver.
When I try to connect to the EFW I get;
Connect():EFWOpen()=4
From 3rdparty/indi-asi/EFW_Filter.h I see;
typedef enum _EFW_ERROR_CODE{
EFW_SUCCESS = 0,
EFW_ERROR_INVALID_INDEX,
EFW_ERROR_INVALID_ID,
EFW_ERROR_INVALID_VALUE,
EFW_ERROR_REMOVED, //failed to find the filter wheel, maybe the filter wheel has been removed
EFW_ERROR_MOVING,//filter wheel is moving
EFW_ERROR_ERROR_STATE,//filter wheel is in error state
EFW_ERROR_GENERAL_ERROR,//other error
EFW_ERROR_NOT_SUPPORTED,
EFW_ERROR_CLOSED,
EFW_ERROR_END = -1
}EFW_ERROR_CODE;
So presumably this means kstars thinks my filter wheel has error code EFW_ERROR_REMOVED
I will try to find a powered hub and see if it works with that.