> > *Latest thoughts on this: I think perhaps the problem is that I should not > expect to see serial data from P9_28 (I2S serial data out) without an > actual Audio Cape. There are probably I2C (control) and I2S (audio > content) requirements, such as clocks and so forth, that are required > before the BBB will output data.* > > *Unfortunately, I know virtually nothing about hardware. * > > *I would just buy an Audio Cape, but I have not seen them in stock > anywhere for the past month, and there seems to be no indication of when > they'll be available again*. >
I had the same idea, and was wondering if the audio would not be cumming out hdmi instead as well. I can verify that a CAN cape behaves this way . .. but it is CAN, and not I2S . . . On Sat, Jul 4, 2015 at 6:24 PM, <[email protected]> wrote: > Just an update on this: I used a scope without a cape (because I don't own > one, and estimated backorder on MCM is 52 days). I verified no life on > AUD_DOUT P9_28, but I _do_ see life on pins 19 and 20, which are the I2C > SDA and SCL lines. As soon as I commence sound output, the SCL goes live > with a regular pulse, and we see an I2C START on SDA. > > So I think this means if I had an actual I2C slave responding to the > proper address, the BBB would then start outputting serial data on its I2S > output pin, P9_28. But without this, I won't see anything. > > So it's not a driver or overlay issue, it would appear. > > On Saturday, July 4, 2015 at 12:44:00 PM UTC-6, Colin Bester wrote: >> >> Yes I have a scope and will run tests for you when I get back to my desk. >> >> Sent from my iPhone >> >> On Jul 4, 2015, at 11:15 AM, [email protected] wrote: >> >> Colin, >> >> That would be phenomenally helpful! Do you have a scope? >> >> I'm curious if you see any life on pin 28 of the P9 header with and >> without a cape. I suspect you will see data with the cape (because the DAC >> on the cape board is talking to the BBB's processor), but nothing without >> it. >> >> I unfortunately don't have a way to "fake" the cape. >> >> >> >> On Saturday, July 4, 2015 at 9:23:59 AM UTC-6, Colin Bester wrote: >>> >>> If it'd help I could run same tests for you with and without audio cape >>> and test the theory - I am running bone68 but suspect results will be the >>> same - it'd be good to know if you can see output or not. >>> >>> On Saturday, July 4, 2015 at 10:19:59 AM UTC-5, [email protected] >>> wrote: >>>> >>>> >>>> Latest thoughts on this: I think perhaps the problem is that I should >>>> not expect to see serial data from P9_28 (I2S serial data out) without an >>>> actual Audio Cape. There are probably I2C (control) and I2S (audio >>>> content) requirements, such as clocks and so forth, that are required >>>> before the BBB will output data. >>>> >>>> Unfortunately, I know virtually nothing about hardware. >>>> >>>> I would just buy an Audio Cape, but I have not seen them in stock >>>> anywhere for the past month, and there seems to be no indication of when >>>> they'll be available again. >>>> >>>> >>>> >>>> >>>> -- >> For more options, visit http://beagleboard.org/discuss >> --- >> You received this message because you are subscribed to a topic in the >> Google Groups "BeagleBoard" group. >> To unsubscribe from this topic, visit >> https://groups.google.com/d/topic/beagleboard/xfv4BY1AiEA/unsubscribe. >> To unsubscribe from this group and all its topics, send an email to >> [email protected]. >> For more options, visit https://groups.google.com/d/optout. >> >> -- > For more options, visit http://beagleboard.org/discuss > --- > You received this message because you are subscribed to the Google Groups > "BeagleBoard" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > For more options, visit https://groups.google.com/d/optout. > -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
