I have the same question open in a Mining help thread here but thought I'd ask you guys who are most knowledgable with cgminer.
Running cgminer 4.10.0 on a Raspberry Pi 3, which is connected to an Avalon AUC3, which is connected to an Avalon 741 ASIC miner. When I start cgminer, I get the following response:
root@OpenWrt:/lib/modules/4.4.14# cgminer -o us-east.stratum.slushpool.com:3333 -O userid.shop100:x -D --verbose
[2016-12-14 02:10:04.665] Started cgminer 4.10.0
[2016-12-14 02:10:04.665] RES: thread starting
[2016-12-14 02:10:04.665] USB scan devices: checking for AV7 devices
[2016-12-14 02:10:04.832] AV7 looking for AV7 29f1:33f2 but found 0424:ec00 instead
[2016-12-14 02:10:04.832] AV7 looking for AV7 29f1:33f2 but found 0424:9514 instead
[2016-12-14 02:10:04.832] AV7 looking for AV7 29f1:33f2 but found 1d6b:0002 instead
[2016-12-14 02:10:04.832] No devices detected!
[2016-12-14 02:10:04.832] Waiting for USB hotplug devices or press q to quit
[2016-12-14 02:10:04.832] Probing for an alive pool
[2016-12-14 02:10:04.832] Testing pool stratum+tcp://us-east.stratum.slushpool.com:3333
[2016-12-14 02:10:04.921] Succeeded delayed connect
[2016-12-14 02:10:05.219] Pool 0 stratum session id: 1
[2016-12-14 02:10:05.220] Pool 0 difficulty changed to 2048
[2016-12-14 02:10:05.221] Pool 0 coinbase 01000000010000000000000000000000000000000000000000000000000000000000000000ffffffff4503f27307fabe6d6d14260e5f1745bbbfd4edaa7f0a102fcfb8ac5ece9a3399e6c37e8f6586741cb80100000000000000036501004fb5f2000000003245072f736c7573682f00000000022b8c185
[2016-12-14 02:10:05.326] Stratum authorisation success for pool 0
[2016-12-14 02:10:05.326] Pool 0 stratum+tcp://us-east.stratum.slushpool.com:3333 alive
[2016-12-14 02:10:05.832] Unable to set thread to low priority
[2016-12-14 02:10:05.832] Unable to set thread to high priority
[2016-12-14 02:10:05.832] Testing pool stratum+tcp://us-east.stratum.slushpool.com:3333
[2016-12-14 02:10:05.833] Unable to set thread to low priority
[2016-12-14 02:10:05.833] Work update message received
[2016-12-14 02:10:05.833] Unable to set thread to low priority
Assuming the plugged in hardware is functioning correctly, what could be causing these messages:
[2016-12-14 02:10:04.832] No devices detected!
[2016-12-14 02:10:04.832] Waiting for USB hotplug devices or press q to quit
Are there downloadable USB drivers for the Raspberry Pi 3? Anyone else ever have this issue and successfully resolve it?
Thanks
Direct USB needs no drivers. Seems like your AUC3 is broke. Alternatively it could be the dodgy usb ports on the pi. Try attaching a decent USB hub to run it off instead.