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There have been 156 items by Magpie (Search limited from 25-April 23)


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#27875 USB Audio Device - FINALLY WORKS!!

Posted by Magpie on 22 April 2012 - 08:24 AM in Project Showcase

I hope that's it, but it's still a bit strange how it would work for an hour though.


#25488 USB Audio Device - FINALLY WORKS!!

Posted by Magpie on 14 March 2012 - 03:49 AM in Project Showcase

Just make it anyway. Olimex can spin up a couple of boards for under 40 Euros. I think it's a good project, and I would like one. I could help a fair bit as I have a bit of a background in Audio.


#27629 USB Audio Device - FINALLY WORKS!!

Posted by Magpie on 19 April 2012 - 08:35 AM in Project Showcase

Oh well Look on the bright side, your still doing better than me. Olimex apparently posted me my boards a month ago, and I still haven't got them. and I've blown up all my chips in the meantime.


#26316 USB Audio Device - FINALLY WORKS!!

Posted by Magpie on 03 April 2012 - 12:44 PM in Project Showcase

It sounds really good? I like the sound of that. It's also good that you have had time to test and tweak things, this might take a lot of the headache out for us D class amp usb audio newbies. Is there an easy way to break into the Audio before the D amp? I might want to provide a more traditional set of Audio inputs as well. May the boards come soon.


#26384 USB Audio Device - FINALLY WORKS!!

Posted by Magpie on 04 April 2012 - 12:24 PM in Project Showcase

I guess it comes down to the fact that the pc is the most versatile source of sound anyway, it can take in a hdmi input and push it down the usb probably.


#26319 USB Audio Device - FINALLY WORKS!!

Posted by Magpie on 03 April 2012 - 01:25 PM in Project Showcase

Doesn't matter so much music can come out of PC anyway. Digital Radio, mp3s, movies. I probably don't need any more.


#27859 USB Audio Device - FINALLY WORKS!!

Posted by Magpie on 22 April 2012 - 12:25 AM in Project Showcase

Maybe just power it up when there is a lightning storm. On the good side, it sounds like you haven't damaged any hardware. It's not a software issue is it? Reboot fixes it? probably not but worth asking. Have you got an oscilloscope? With what you said about the oscillator, checking the clock would be a good place to start. You could also check all the pins to look for invalid inputs. Do you have a schematic? And a pcb file I could look at?


#26339 USB Audio Device - FINALLY WORKS!!

Posted by Magpie on 03 April 2012 - 10:46 PM in Project Showcase

What about standard HDMI inputs? Do have any idea if it is feasible to add them?


#27450 USB Audio Device - FINALLY WORKS!!

Posted by Magpie on 17 April 2012 - 12:20 PM in Project Showcase

After a while, the usb chip seem to get hot, no magic smoke but it smells


That's no good.
I know almost nothing about your schematic and I know you probably already know this stuff, but I will throw in my 20 cents anyway just in case there is something that could help.


It sounds like a short somewhere, hopefully not in one of the main chips.
Assuming your circuit design is good.

You can short pins with static.
Or maybe its in the pcb
or your soldering is probably crap (just kidding).

Do you have a current limited voltage supply?
If it is a short you can turn it on at a lower than normal voltage, so you get some abnormal current, say 300mA, but just enough so nothing new is cooked.
And if you have an accurate multimeter you can trace millivolts to find where the short is.

Good luck, (I'm also giving you a bit of moral support just in case the above doesn't help.)


#26371 USB Audio Device - FINALLY WORKS!!

Posted by Magpie on 04 April 2012 - 10:40 AM in Project Showcase

I know nothing about hdmi, but I think in the near future I am going to learn.


#27706 USB Audio Device - FINALLY WORKS!!

Posted by Magpie on 20 April 2012 - 11:42 AM in Project Showcase

At least you believe your board exists, mine must be in some sort of quantum state.


#27919 USB Audio Device - FINALLY WORKS!!

Posted by Magpie on 23 April 2012 - 03:57 AM in Project Showcase

Hi Hanzibal
There is a lot of stuff here that I am not very experienced in but ignore that and I will try to give you some extra ideas.

It seems the crystal is ok. If you cant actually get to the clock pulse because it's internal to the chip and the crystal looks good, what else can you do but assume it is good.

I am not sure your decoupling circuitry is correct, but it is hard to see from the photos.
both C5 and C7 according to the reference design should have a 1uF ceramic in parrallel to a 10uF electro. the ceramic should be as close as possible to the pins.
all other ceramics should probably be the very close to their pins as well.
Are they ceramic? some have that baby shit brown colour that they use on tantalum caps.


I guess the standard approach is to debugging digital circuits is.
  • Check all grounds. (Voltages)
  • Check all power.
  • check clock (it seems to be entirely internal, so check crystal which you have done.)
  • check all inputs for irregularity, such as indeterminate logic states, unexpected noise or waveforms, and if you can check the expected logic state is there.
after this it will be circuit specific.

Lastly what I often find is a good way to solve problems that are complicated, is to
start with something that is working and keep adding to it until you add the thing that breaks the system,
this works better than starting with something that isn't working and trying to work backwards.
In your case, did you have a breadboard that does work? does it still work? What is different?

Think to yourself this is where I earn my money. (while you look for needles in a haystack.)

The other obvious place for the problem is in software.

By the way how does it stop working, does the usb driver stop talking?<br><br>


#28329 USB Audio Device - FINALLY WORKS!!

Posted by Magpie on 30 April 2012 - 08:25 AM in Project Showcase

Good work Hanzibal I guess the music must sound even better after all the trouble and effort it's caused.


#28590 USB Audio Device - FINALLY WORKS!!

Posted by Magpie on 06 May 2012 - 04:02 AM in Project Showcase

Looks great Hanzibal If you can waste an extra bit of time, you might want to put a nicely done graphic on the silkscreen with a picture of a "Frankencat". Maybe something like a cat with bolts in its neck and a bit of lightning nearby. You think I am joking, but I am not.


#46570 USB Audio Device - FINALLY WORKS!!

Posted by Magpie on 03 March 2013 - 08:00 AM in Project Showcase

Hi Hanzibal

I did say I wanted a board but money is a bit tighter these days than last year. But I wont say a definite no as my music is gradually moving to hard disc, and your system could be useful. But I have a few unfinished things I need to do, so a new project is not high on the list.

 

Did you ever get to the bottom of your Crystal problems or did the oscillator just fix everything? I will probably lay out a board with a crystal soon. I normally just get an internal oscillator on the chip.



#28243 USB Audio Device - FINALLY WORKS!!

Posted by Magpie on 28 April 2012 - 01:56 AM in Project Showcase

Good to hear that it can play a whole album now. The good thing is that it's been a good learning experience for you and also for me. My experience with crystals is still basically zero, just put them in and dont worry about them. So I will be interested if you do finally work out what is going on. Bear in mind my scant knowledge of crystals when you read the following. One thing that seems strange is shouldn't the crystals dc offset be about half of the logic voltage? I am just saying this because I thought I read it somewhere and if you look at the block diagram, one pin is connected to a logic gate output, so you would think that it has a square wave on it. You said it was 3V on a logic level of 3.3.


#29263 USB Audio Device - FINALLY WORKS!!

Posted by Magpie on 16 May 2012 - 01:53 PM in Project Showcase

I guess I just have my head stuck in old world analogue electronics.


#28260 USB Audio Device - FINALLY WORKS!!

Posted by Magpie on 28 April 2012 - 11:40 AM in Project Showcase

It seems that spotify can't licence in Australia at the moment. The music powers that be dont want any competition.


#46933 USB Audio Device - FINALLY WORKS!!

Posted by Magpie on 09 March 2013 - 01:43 PM in Project Showcase

Hi Hanzibal

 

On the subject of Oscillators here is a short app note on them. It seemed pretty good. Apart a typo on one of the schematics, where L1 uses a capacitor symbol.

 

http://www.euroquart.../tech-notes.pdf

 

I didn't find to much talk on symmetry though.



#28264 USB Audio Device - FINALLY WORKS!!

Posted by Magpie on 28 April 2012 - 02:06 PM in Project Showcase

Sorry Hanzibal

I can't see anything that could be the cause of this problem, that hasn't been mentioned already.

Did you check ALL your ground pins have good contact with ground?

Here is an oscillator that looks similar to yours

My link

The only other thing I can think of is can you move the components on your breadboard to get a similar behaviour? This again would be a lot of effort for little chance of success.


#28978 USB Audio Device - FINALLY WORKS!!

Posted by Magpie on 13 May 2012 - 11:13 PM in Project Showcase

Thanks, sorry for the delay, just got back from a week's vacation in France and Italy.

I would love to have a logo of a "Frankencat" and started thinking in line with your suggestion. I'm not much of a router but still considering to maybe integrate the amplifier on the same board, I mean it's kind of scares now plus there's two sides to play with.

Could be there's not much room for a logo then even if I go up to 100x80mm which is the limit of the free version of Eagle.

What you think?


I guess it wouldn't be good to make the board size bigger just to fit a logo, but maybe just fit whatever you can.

Also I think you should watch the separation of the power stage and the preamp stage, to make sure you don't get inadvertant feedback and hum.
It's been a while since I considered these problems, and sometimes they are not really problems at all.
I am just mentioning the following as a possibility, it is a bit of extra cost and complication.


I think what proved to be the best strategy for noise immunity was to connect the power and common as a star, back to the main power section, and pass the analogue signals around as balanced signals.
Balanced signals are balanced around the common voltage rail.

eg Unbalanced
wire 1. common 0 volts
wire 2 signal 1 sin(wt) volts.

Balanced
wire 1. common 0.5 sin(wt) volts.
wire 2 signal - 0.5 sin(wt) volts.

in either case the signal level is the same but the balanced system has more noise immunity.
I don't think you really need to go this path, but I am sure that most high end equipment uses this type of interconnection whenver possible, between boards and between devices.


#28318 USB Audio Device - FINALLY WORKS!!

Posted by Magpie on 29 April 2012 - 11:09 PM in Project Showcase

Sorry, I must have missed something. You found the problem? Congratulations if it's true.


#30885 USB Audio Device - FINALLY WORKS!!

Posted by Magpie on 19 June 2012 - 01:02 PM in Project Showcase

Dont get distracted by paying work, spend more time on your hobby projects. When is the full system coming out?


#25928 [UK] Electrical Supply help

Posted by Magpie on 24 March 2012 - 12:21 PM in General Discussion

Yes I did see you said undervoltage, I just made a big presumption that only overvoltage will take out the light globes. Anyway hopefully you have found the cause of your troubles. Good Luck


#25924 [UK] Electrical Supply help

Posted by Magpie on 24 March 2012 - 11:38 AM in General Discussion

Hi Do you have smoke alarms? If you dont you should get some, even though they are annoying. Like Mario I find it difficult to see how a blowing light bulb would take out a circuit breaker. I am not saying it didn't happen but it's hard to understand. The only reasons I can think of for overvoltage on your mains are line surges or a broken neutral. Broken neutrals I would say are quite uncommon but can have serious consequences. If you ring up your supply Authority and say you suspect you have a broken neutral they might come and inspect for free. Can you get a second sparky in to verify the safety of the installation, especially the neutral and the earth connections, don't get the first one he may be dodgy, I would say it might be two hours work. Otherwise can you just turn off any dodgy circuits, at the switchboard and see if the rest of the house is ok? I wouldn't be getting the multimeter out unless you know what you are doing, and you are in a clear state of mind.



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