Pandora Sound Hardware

[nikkopt]

I actually have a few questions related to pandora's sound hw;
is it possible to drive a mic input from the ext ports line out? The headphone output supports a mic in tru the same jack (4 contacts)
Eg. Is there a low enough volume setting(s) (thats not mute) for this? not sure, so i won't answer
Also, can the pandoras sound system direct audio from the internal mic to ext line out with minimal cpu usage? yes
Can it also direct ext line in to speakers while doing this? yes
Can the speakers,line out and headset line out play different audio streams? no

Now, i want no guesses as answer; Either you have a pandora devboard and you tested stuff and/or you've read the correct datasheets and know the answer.

 

[urjaman]

Now i blindly trust that nikkopt knows his answers are true.

The headphone output supports a mic in tru the same jack (4 contacts)

i know this, by "external mic input" i meant not a mic but a device with mic level input.

Also, can the pandoras Can the speakers,line out and headset line out play different audio streams? no

care to specify more?
Because according to the 2 yes's above ext line out and speakers can output different streams. Is it that one/both of them is of a "only redirect" type? I mostly wanted to ask that would the pandora be able to do "speakerphone" while (for example) playing mp3 on the headset output - or mix mp3 to the line in audio data before playing result on the speakers or headset?

 

[nikkopt]

Now i blindly trust that nikkopt knows his answers are true.

The headphone output supports a mic in tru the same jack (4 contacts)

i know this, by "external mic input" i meant not a mic but a device with mic level input.

Also, can the pandoras Can the speakers,line out and headset line out play different audio streams? no

care to specify more?
Because according to the 2 yes's above ext line out and speakers can output different streams. Is it that one/both of them is of a "only redirect" type? I mostly wanted to ask that would the pandora be able to do "speakerphone" while (for example) playing mp3 on the headset output - or mix mp3 to the line in audio data before playing result on the speakers or headset?

about the mic: without an external amp, i'm almost pretty sure you can´t
about the different audio streams: when you connect a headset, the jack insertion detector disables the speakers (at least i'm guessing the devs are using this functionality). But yes, the headset output and the speakers don't share the same interface, both connect to the TWL but they use different dac's, amps and even different pin connectivity on the TWL. I just don't know if the OS recognizes them as separate lines, they could just be separate to help you build your device. I'm sure the TWL manual speaks about it. http://focus.ti.com/lit/ug/swcu050d/swcu050d.pdf

PS: You really shouldn't trust me, lol MWeston can answer you correctly

 

[borgqueenx]

its a notebook/media player/gaming console - loud good quality speakers are welcome.
External speakers, no thanks. i dont want to carry 5 devices for doing everything better and faster.

But i cant chance anything and im happy about how it is, exept the speakers that is.

 

[urjaman]

A bit OT, but cant resist. . .

I'm sure the TWL manual speaks about it. http://focus.ti.com/lit/ug/swcu050d/swcu050d.pdf

PS: You really shouldn't trust me, lol MWeston can answer you correctly

I've read that pdf partially (some time ago) but i was mostly interested in the power management back then and skipped the audio chapter. At the moment i cant read pdfs - my internet device is my nokia 6630 and im in the middle of lapland (in northern finland) at a finnish defense force's "military excercise" / "war game" (wikipedia translation). I'll read the pdf and get back on this subject next weekend.

 

[bzar]

A bit OT, but cant resist. . .

I'm sure the TWL manual speaks about it. http://focus.ti.com/lit/ug/swcu050d/swcu050d.pdf

PS: You really shouldn't trust me, lol MWeston can answer you correctly

I've read that pdf partially (some time ago) but i was mostly interested in the power management back then and skipped the audio chapter. At the moment i cant read pdfs - my internet device is my nokia 6630 and im in the middle of lapland (in northern finland) at a finnish defense force's "military excercise" / "war game" (wikipedia translation). I'll read the pdf and get back on this subject next weekend.

A bit more OT, but I can't resist either...

What's your "TJ"?

 

[urjaman]

To MWeston - can you say what audio pin's on the TWL are used for pandora's audio IOs?

This is what i now assume:
Main speakers = ihf_{left,right}_{p,m} (8 ohm hands-free amplifier)
Internal Mic = mic_main_{p,m} (Main microphone)
Ext Port Line In = aux{r,l} (Auxiliary Input)
Ext Port Line Out = predriv_{left,right} (External Class-D predriver... this i'm not sure of)
Headset (jack) = hso{l,r} (32-ohm headset amplifier)
Headset microphone pin = hsmic{p,m} (Headset micdrophone)


I've investigated the TWL datasheet and it seems like it can only use two channels (right and left) of input at one time (from the Block Diagram, only two input ADC's) - but it would be just enough if i can use it like this:
Input Channel R = Ext Port Line In Right - routed to both Main Speakers
Input Channel L = Internal Mic - routed to Ext Port Line Out Left (or Right)

AFAIK the system should also be capable of playing different audio on the Headset while doing this.

I looked mostly at the Block Diagram for this - not 100% sure yet but i think it's possible to have my speakerphone

 

[edcowden]

Hooking up a mic should be fairly straightforward - just get a USB mic -- or maybe use the MicPort Pro, which turns any XLR mic into a USB mic. Super portable, Phantom power, headphone monitoring, and has been plug-and-play on every PC and Mac I've thrown it at so far.

Will just need some recording/editing software...

 

[MWeston]

To MWeston - can you say what audio pin's on the TWL are used for pandora's audio IOs?

Internal microphone - TPS65950, MAIN MIC
External microphone (on headphone connector) - TPS65950, SUB MIC
Line Inputs - TPS65950, AUX INPUTS (shared with mics inside TPS65950 so you can set muxes to use one line and one mic channel if you want)
Line Outputs - PCM1773, line level output shared between headphone amp and EXT connector, no volume control (2.15Vpp output, 10K load)

Audio inputs use McBSP4 and audio outputs use McBSP2 so they can run simultaneously with different audio on them. BT is on McBSP3 for reference.

The audio output of the TPS65950 is not connected on the PCB but I read in the TRM it might be possible to route it out of the USB OTG port for four channel audio (six channel if you stream over BT too). That might take some clever coding to hack into the kernel, but neat if it works some day. I could be wrong about it working like this, but I found information in that carkit section for USB.

 

[peca]

The audio output of the TPS65950 is not connected on the PCB but I read in the TRM it might be possible to route it out of the USB OTG port for four channel audio (six channel if you stream over BT too). That might take some clever coding to hack into the kernel, but neat if it works some day. I could be wrong about it working like this, but I found information in that carkit section for USB.

So, if I understand correctly and You are right, then there could be 4 channel audio out? For example for playing at home TV or even if Pandora Cube will hereafter exists or for connecting to multichannel home audio system.

 

[WhiteBat]

So, if I understand correctly and You are right, then there could be 4 channel audio out? For example for playing at home TV or even if Pandora Cube will hereafter exists or for connecting to multichannel home audio system.

take a look at this thread ;D

http://www.gp32x.de/board/index.php?/topic/45093-details-and-specs-of-the-pandoras-sound-card/