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The LCDuino-1 I/O processor

Feb 28, 2010 at 8:48 PM Post #256 of 403
Quote:

Originally Posted by Beefy /img/forum/go_quote.gif
How do you find the relay solution compares to your PGA 23** solution? Sound quality, difficulty to implement, any perspective would be great......
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I brought one of my PGA air-wire test setups over to amb's place and we ran an rmaa on it. I believe at that time, it was essentially at the noise floor level of the test equip (we likely used the m-audio RME box). whatever the rme was at, the PGA was just about at that level, too. ie, it was very very good and surprised us both, to be honest.

once the relays board is laid out and the testers have them in their hands, then the pga stuff can be revisited. for my own 5.1 use, I really want to have 3 of those pga's and so I'm personally interested in this chip/series, to be sure
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Feb 28, 2010 at 11:22 PM Post #258 of 403
Quote:

Originally Posted by linuxworks /img/forum/go_quote.gif
please don't speak for me. as I've written in a few posts, today, this is just not the case.

thanks.


I'm not sure what you're deal is. Beefy asked a question and I referred him to a post that answered it.
 
Feb 28, 2010 at 11:27 PM Post #260 of 403
Quote:

Originally Posted by linuxworks /img/forum/go_quote.gif
please don't speak for me. as I've written in a few posts, today, this is just not the case.

thanks.


If he's referring someone to something that you had previously posted, he's not speaking for you, you did that all on your own.

That's all I'm saying.
 
Feb 28, 2010 at 11:42 PM Post #261 of 403
I couldn't remember the exact words... "shelved"? "abandoned"? whatever.. I summarized it from my memory instead of finding the exact post... yes, i put the word in quotes as it was my addition. Perhaps I should have used [sic] as well?

Then, i found the exact post and quoted it to clear things up.
 
Feb 28, 2010 at 11:46 PM Post #262 of 403
I'm trying to understand where this is coming from.

looking back at what I posted, I see on page12:

"some devel news: today I have the PGA volume control chip (pga23xx series) working across i2c via a port expander chip. I'm using a phliips PCFxxx series chip (for variety) and can remotely send {chipselect, clock, data} over i2c via a 'bit bang' at the i2c message level "

so in november, I was experimenting with 'remoting' the pga across an i2c chip and bit-banging it. that worked and I used that in my m3 amp for a few months.

then on page14, I say:

"also, turning my attention to relay attenuation control circuits."

and so that means, to me, that I've added more things to the project, not removed any.

sorry if that was not clear.
 
Mar 1, 2010 at 12:05 AM Post #263 of 403
Quote:

I took a detour to try out a digital pot and see if it was usable directly in the audio path. turns out it wasn't


I think the above statement is the source. Personally, if I said something wasn't usable directly in the audio path, that would imply that it was no longer being worked on and a release wasn't being planned. Am I the only one who read things that way?
 
Mar 1, 2010 at 12:12 AM Post #264 of 403
Regardless of what was posted or interpreted, the fact is we have not abandoned anything. Relay-based attenuator and input/output selector modules are what we're going to release first, but we plan to add other modules in the future.
 
Mar 1, 2010 at 12:52 AM Post #266 of 403
Would there be any possibility of using the input select board or controller with a different I/O board? I am looking at making a board which would have 4 bal. and SE inputs, bal and SE monitor outs and bal and SE outputs, with a muting relay on the output. All inputs would have on-board relays.
 
Mar 1, 2010 at 1:17 AM Post #267 of 403
Quote:

Originally Posted by Pars /img/forum/go_quote.gif
Would there be any possibility of using the input select board or controller with a different I/O board? I am looking at making a board which would have 4 bal. and SE inputs, bal and SE monitor outs and bal and SE outputs, with a muting relay on the output. All inputs would have on-board relays.


if I understand you correctly, you want to use the lcduino1 as the controller but have it talk to your own board?

its open-source and so yes, you should be able to 'software glue' your board to the lcduino1. if you use i2c it might be easier (as there will be examples to follow, to speed your customization).

what you would do is to find the action routines (when the user presses 'input button 1', say) and then call your routine instead of the built-in one. like that.
 
Mar 1, 2010 at 2:08 AM Post #268 of 403
Chris, I'd expect that you'd need more circuity on your board that what you mentioned. (Perhaps you didn't give an exhaustive list?) For example, do you plan on having relay driver on the board and control mechanism as well?
 
Mar 1, 2010 at 3:16 AM Post #269 of 403
Quote:

Originally Posted by luvdunhill /img/forum/go_quote.gif
I think the above statement is the source. Personally, if I said something wasn't usable directly in the audio path, that would imply that it was no longer being worked on and a release wasn't being planned. Am I the only one who read things that way?


Digital Pot =/= PGA volume chip

I believe that is the source of your confusion. He abandoned the digital pot because it was hard to implement because of the input constraints. The PGA chip, on the other hand, had great results but requires a dual supply and is a little harder to implement, so I believe it was decided that the relay board would be the quicker and "cleaner" implementation for now, but the PGA is still on the table. Someone correct me if I'm wrong, I don't mean to put words in anyone's mouth.
 
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