levi
Still fresh, damnit!
Not through the TRRS connection for sure - there's only one ring for mic, so that's mono. As noted above though, there are cheap USB solutions to almost all of your audio worries.
Line-In for the Pyra
- Thread starter RHCA
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Do you know of any that are compact, powered from the USB port and have drivers for linux?
How was the line-in realized on the Pandora? I mean the hardware part of it. I know, there is that separate dac for playing sounds, but what about the line-in adc?
Eventually it would be an idea to leave solderpads on the i2c line on the board to allow hackers to connect such an adc for their needs (if the bandwidth is great enough)?
EDIT: Another thing I've seen some time before was audio through USB on an active Speaker. The data-pins of the micro USB port were used to transmit the 2 sound channels, ground were connected to ground and the 5V line was used to charge the device. It would also be nice to know if there would be a possibility to change the mode of the microUSB port, to allow line in through that (from serial mode to line-in mode). So all you would need to have is an adapter cable
Eventually it would be an idea to leave solderpads on the i2c line on the board to allow hackers to connect such an adc for their needs (if the bandwidth is great enough)?
EDIT: Another thing I've seen some time before was audio through USB on an active Speaker. The data-pins of the micro USB port were used to transmit the 2 sound channels, ground were connected to ground and the 5V line was used to charge the device. It would also be nice to know if there would be a possibility to change the mode of the microUSB port, to allow line in through that (from serial mode to line-in mode). So all you would need to have is an adapter cable
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slaeshjag
¯\_(ツ)_/¯
Probably a better idea to leave pads for I²S in that case
WizardStan
Mega GP Mania
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- May 24, 2008
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I believe the OMAP5 only has one i2s port and that is almost certainly being used by the cell phone module, unless a USB channel is being used or gta04 has found some other way that I'm not aware of.
But unless he or EvilDragon pipe in and say otherwise I think it's safe to assume no i2s port will be available. i2c should be fine though, I hope hack pads are left available for that.
But unless he or EvilDragon pipe in and say otherwise I think it's safe to assume no i2s port will be available. i2c should be fine though, I hope hack pads are left available for that.
slaeshjag
¯\_(ツ)_/¯
I²C might work, assuming we get a dedicated high-speed one (supporting >= 3.4 MHz). Anything connected to stuff like nubs will probably be at 400 kHz and thus be useless for audio.
EDIT: Though, SPI could be used as a poor-mans I²S. Though, it might have a significant inpact on CPU-load. Not that I²C won't have that.
EDIT: Though, SPI could be used as a poor-mans I²S. Though, it might have a significant inpact on CPU-load. Not that I²C won't have that.
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levi
Still fresh, damnit!
I can't recommend any as I have no personal experience of them, but searching on Amazon showed me plenty of USB-powered sound cards, most of which included a line in either via RCA/Phono or 3.5mm stereo socket. There are reviews confirming at least some of them work in Ubuntu, though I can't say for sure if that's using a free driver or not.
The search isnt so easy for linux. There is a standard USB audio class compliant spec. for USB audio devices, which should work without custom kernel driver modules.
Here a few were tested: http://www.audiomisc.co.uk/HFN/ADC/USBrecording.html
EDIT: The behringer UCA-202 looks driverless and is USB-powered, with 2x RCA line-inputs.
If anyone has used a USB ADC on Pandora (EDIT: or desktop linux), please post here.
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haven't read through the whole topic, but I think I got the gist of it by skimming. I was a little underwhelmed at first that there isn't going to be a line-in on board but then thought about it a little.
I use my pandora a lot at work for playing back samples, music and synth atmos. what you really want to have if you are recording or sourcing stuff into a PA is certainly not mini jack. worst connectors ever for professional use. good enough for tinkering but really you need decent XLR or 1/4" jack connectors without any adapters for a proper signal and reliable operation.
so if there were hackable pads that would be preferrable to me as I'd love to be able to attach some decent XLR combo connectors somehow.
I use my pandora a lot at work for playing back samples, music and synth atmos. what you really want to have if you are recording or sourcing stuff into a PA is certainly not mini jack. worst connectors ever for professional use. good enough for tinkering but really you need decent XLR or 1/4" jack connectors without any adapters for a proper signal and reliable operation.
so if there were hackable pads that would be preferrable to me as I'd love to be able to attach some decent XLR combo connectors somehow.
Are you sure those active speakers used analogue audio through the data lines? Seems more likely to me that the speakers used standard USB, and an on-board DAC inside the speakers.How was the line-in realized on the Pandora? I mean the hardware part of it. I know, there is that separate dac for playing sounds, but what about the line-in adc?
Eventually it would be an idea to leave solderpads on the i2c line on the board to allow hackers to connect such an adc for their needs (if the bandwidth is great enough)?
EDIT: Another thing I've seen some time before was audio through USB on an active Speaker. The data-pins of the micro USB port were used to transmit the 2 sound channels, ground were connected to ground and the 5V line was used to charge the device. It would also be nice to know if there would be a possibility to change the mode of the microUSB port, to allow line in through that (from serial mode to line-in mode). So all you would need to have is an adapter cable
As long as we're considering switchable port functionality maybe it would be easier to add a switch to the headphone out port to allow it to act as line-in, if desired.
Yep, I'm sure. There was a USB-A plug on the other side and a 3.5 jack, so it seems to me the sound gets transmittet through the "data lines". But i dont know how switching modes could be realized?Are you sure those active speakers used analogue audio through the data lines? Seems more likely to me that the speakers used standard USB, and an on-board DAC inside the speakers.How was the line-in realized on the Pandora? I mean the hardware part of it. I know, there is that separate dac for playing sounds, but what about the line-in adc?
Eventually it would be an idea to leave solderpads on the i2c line on the board to allow hackers to connect such an adc for their needs (if the bandwidth is great enough)?
EDIT: Another thing I've seen some time before was audio through USB on an active Speaker. The data-pins of the micro USB port were used to transmit the 2 sound channels, ground were connected to ground and the 5V line was used to charge the device. It would also be nice to know if there would be a possibility to change the mode of the microUSB port, to allow line in through that (from serial mode to line-in mode). So all you would need to have is an adapter cable
As long as we're considering switchable port functionality maybe it would be easier to add a switch to the headphone out port to allow it to act as line-in, if desired.
The other idea of switching the TRRS Port isn't so well thought. That works only if you just want to record, and do not play at the same time. Sure, there would be the HDMI port for sound output, but that wouldn't be a nice solution...
I do not see how a standard USB host (laptop, pc etc) could send analogue audio out of a USB port. Maybe some hardware guru could offer an opinion here.
Good point on not blocking the output of the TRRS port - it would be a disadvantage to disable audio-out to get line-in.
I will probably end up buying the Behringer ADC/DAC for preserving my old recordings and maybe making new recordings with the pandora.
No, you misunderstood, (but thats my fault...) the micro USB port on the speaker doesn't act like a standart USB port! It's only used to charge the battery and connect line in (over the "data lines"
). Which means it has nothing to do anymore with USB than the plug ^^" So my idea was to be able to switch between the serial console and that line in function. But I don't it would be that easy to realize?EDIT: I remember that the latest iPod Shuffle uses just one 4 pole 3.5 Jack for auidooutput/input and USB. You know what I mean? How does that act electrically?
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levi
Still fresh, damnit!
It's all possible with a few extra transistors and wotnot to switch in one circuit over another, but the question is, is it worth doing it? You don't only need the hardware, but also someone to write the software to switch it, and the time to cope with the people who's USB is 'broken' because they forgot they'd switched it to some other mode.
There's also the problem it's non standard, so you won't be able to buy any parts to fit it, but you'll have to roll your own, which strictly limits how useful it'll be. Not that having non-standard parts is an issue for a company like Apple, but it's not the way we roll around here.
I dunno, I'd be more supportive of your idea if things like those Behringer kits don't work over standard USB. I'd also be interested to hear if those work.
There's also the problem it's non standard, so you won't be able to buy any parts to fit it, but you'll have to roll your own, which strictly limits how useful it'll be. Not that having non-standard parts is an issue for a company like Apple, but it's not the way we roll around here.
I dunno, I'd be more supportive of your idea if things like those Behringer kits don't work over standard USB. I'd also be interested to hear if those work.
Hmm... But I think there would be any problem, if the serial console is setup as standart. When connected to a Host, nothing (bad) would happen, it gets discovered as a serial device and if somebody chooses to switch to the line in mode, he knows that he switched modes. Also line in is passive, which means if it happens that you connect USB to line in, it should't kill everything (As long as you don't short some circuits). Correct me if I'm false... Also look my edit. How I said, the iPod Shuffle uses the same plug for Headset and USB connection and discovers automatically which one of both is plugged in. So there would actually be the possibility to add this feature
The argument about the non standart thing is right, It would serve some kind of adapter cables. But look on the TV-Out cable of the Pandora, that was also "non standart" and had to be made, and nobody cared much. In this case it would be even easier to create such an adapter, cause of the aviability of USB cables and Audiocables (also just the plugs). And sure, the driver would have to be made, but I don't think that would be the main problem. We've got some very experienced devs here on the board And if it takes Two MonthsTM to enable this feature, nobody would care much about (I hope ^^"). Important is, that there is the possibility to have a line-in.
The argument about the non standart thing is right, It would serve some kind of adapter cables. But look on the TV-Out cable of the Pandora, that was also "non standart" and had to be made, and nobody cared much. In this case it would be even easier to create such an adapter, cause of the aviability of USB cables and Audiocables (also just the plugs). And sure, the driver would have to be made, but I don't think that would be the main problem. We've got some very experienced devs here on the board
And if it takes Two MonthsTM to enable this feature, nobody would care much about (I hope ^^"). Important is, that there is the possibility to have a line-in.If nobody cares about the feature it is not worth building-in. My feeling is that an additional 1/8" jack for line-in would make the Pyra useful to a number of people with 500 euro to spend. But that is just my feeling.
There is still a difference between "the hardware supports it" and "there is no way to do that". I meant no one of the customers would mind, if this feature gets enabled some months after the release. It's not a primary feature, so there shouldn't be any real problem. Of course a simple adiuo jack, which size ever (except that huge one) would be the best solution, your right! But if there's no way to make that fit, we need some alternatives...
levi
Still fresh, damnit!
A few corrections - serial console is NOT standard, or at least I very much hope it won't be. I'd hope USB host, or off (to save power) is the default, not serial TTY mode. Connecting something in the wrong mode shouldn't kill anything, though USB voltages are high end for line-level, so you may pop something if you've not set your gains defensively, but I guess that's something you'll only do once.
So setting it to line in mode by default would be safer, and only switch it to USB mode once something's negotiated a USB connection, but I can't imagine many early adopters being happy waiting 2 months for a working USB connection. And wiring it up in a way that allows it to accept USB noise and analogue noise at the same time means my idea of blankly switching the lines wouldn't work, but there's probably a way to do it, but my electronic knowledge doesn't proceed that fair I'm afraid.
And this is not analogous to the TV-out cable. While that was non-standard, it also used a non-standard connector. This would be a standard connector with a non-standard use, thereby confusion is likely to ensue.
It's a neat idea, but I'm not sure how easy it is to implement the hardware and software switching, and how much time it's worth spending on something that you can achieve alternately by plugging in a 25 quid box of magic. From my little research now, those Behringer boxes look pretty smart. Reportedly, they use a Burr-brown ADC/DAC like the Pandora does. I might have to get one now!
So setting it to line in mode by default would be safer, and only switch it to USB mode once something's negotiated a USB connection, but I can't imagine many early adopters being happy waiting 2 months for a working USB connection. And wiring it up in a way that allows it to accept USB noise and analogue noise at the same time means my idea of blankly switching the lines wouldn't work, but there's probably a way to do it, but my electronic knowledge doesn't proceed that fair I'm afraid.
And this is not analogous to the TV-out cable. While that was non-standard, it also used a non-standard connector. This would be a standard connector with a non-standard use, thereby confusion is likely to ensue.
It's a neat idea, but I'm not sure how easy it is to implement the hardware and software switching, and how much time it's worth spending on something that you can achieve alternately by plugging in a 25 quid box of magic. From my little research now, those Behringer boxes look pretty smart. Reportedly, they use a Burr-brown ADC/DAC like the Pandora does. I might have to get one now!
Neelix
Insecticidal Maniac
I think you're missing that the Pyra will have an additional micro-USB connector designed to be a dedicated charging/debugging port which will default to a serial console mode. This is separate to the USB3/OTG micro-USB connector and the 2 USB A connectors. I'm pretty sure that's the port that Ligachamp is suggesting be adapted.
- Neelix
