On Thursday, 5 January 2017 12:17:05 GMT Ralph Corderoy wrote: > > I ran lsusb on the hub Terry tried and it does show up as single-TT, > > although it does show up as 4 hubs. > > I filtered out some of its more interesting lines to try and lessen the > noise, giving http://pastebin.com/GSu1Cb8A > That says "bDeviceProtocol 2 TT per port" a couple of times so I think > it may be multi-TT? > > Terry, how about using the Pi Zero's GPU to do audio on HDMI for one > output, and putting a single USB audio adapter directly into its OTG > port for the other? No hub. You've GPIO for the RTC IIRC. And if you > need networking then there's the UART and PPP?
I've been shopping; so haven't tried any of the suggestions made to date. However, I did post an update to my query on the Raspberry Pi Forums before I went out: https://www.raspberrypi.org/forums/viewtopic.php?p=1092584#p1092584 This outlines a couple of theories that I have after reading your link to the Pi documentation. I rather suspect that the RPi 2 and 3 hubs are not multi- TT, so I'm leaning towards the multi-core effect as being the reason that the bigger Pis work. Your suggestion to use a HDMI adaptor has merit and in fact was one solution that I looked at very early on in the design. I will still need a hub though, because we said that we would put the MP3 files onto a USB stick, so that the WMT staff can change them without having to speak linux. That would put the Audio Adaptor back in the hub (only one though) and I've definitely seen lock- ups with only one Adaptor plugged in. Also. The HDMI Adaptor would increase the number of different devices which might need sparing, whereas we already have a Pi 3 + one spare for the webserver part of the development. We would either live without the spare or bite the bullet and buy one more. -- Terry Coles -- Next meeting: Bournemouth, Tuesday, 2017-02-07 20:00 Meets, Mailing list, IRC, LinkedIn, ... http://dorset.lug.org.uk/ New thread: mailto:[email protected] / CHECK IF YOU'RE REPLYING Reporting bugs well: http://goo.gl/4Xue / TO THE LIST OR THE AUTHOR
