[Noisebridge-discuss] arduino+wave shield+external power supply issue

[Taylor Fitzgerald]

Hey all. I was up all night and it's definitely not the power  
supplies. They meter out correctly under no load and Multiple wall  
warts work under varying voltages and loads on sketches not involving  
the wav shield.  Ie fading, etc

Another fella on adafruit had similar problem using both wave  
libraries and he just had bad solders somewhere on his wave shield.

Another wave library has helpful debugging lines that I cross checked  
in forums for waveshield problems. It's always solders or a bad part.   
It's possible that I shorted the board by soldering jumpers but it  
works flawlessly over USB, just not on any other converted dc voltage.  
I tried em all.

Funnily enough it 'catches' and plays when the volume is mid to high  
and wont if it's low or off usually.  Like it only wants to if the  
power is being drawn to the speakers.

I don't know, after spending all night learning and debugging it's  
nuances I'm almost certain I just have a funky wave shield. Theres  
weird little glitches mine has, and Everyone elses works without a  
hitch usually.

If there's one around the city to buy / or troubleshoot with that  
would be helpful.

I'm simply wiring 40 bright narrow and clear LEDs from pwm dig io 6 in  
parallel fir the model. Unfortunately It would b about 20 times  
brighter if it worked but I think it'll work for now.

I tried to bit bang digital io 7 but it's quite erratic and I'm not  
good enough yet to smooth it so I'll just stick wih pulsing 6 for now.

And yes I'm running shield 1.1

Thanks!

Taylor f


On May 16, 2010, at 10:44 AM, Andy Isaacson <adi at hexapodia.org> wrote:

> On Sun, May 16, 2010 at 10:20:47AM -0700, Michael Shiloh wrote:
>> he's been using usb power while developing, but now it's time to  
>> switch
>> to external power.
>>
>> as soon as he plugs in his 12VDC external power supply, the program
>> stops working as it should have.
>>
>> if we re-attach the usb cable to get debugging messages, we get
>> gibberish, as if the baud rate is off. the length of the messages and
>> the timing is about right though.
>>
>> any ideas? i've never used the waveshield before but i can't  
>> believe it
>> cares about the input power to arduino. by my quick glance it has its
>> own regulator, but i didn't actually find the schematic (a pointer to
>> this would be most helpful).
>
> That's odd, I can't explain the apparent baud rate issues.
>
> Does he have a Waveshield 1.0 or 1.1 ?  The 1.1 has some significant
> improvements (compatability with more SD cards primarily) but I don't
> think they should affect this problem.
>
> I wasn't able to find the Waveshield1.1 schematic PNG on adafruit.com,
> so I asked someone to render a copy from the Eagle .scm file.  The
> rendering is up at
> http://web.hexapodia.org/~adi/tmp/waveshield11.png
>
> The Waveshield has a 3.3v regulator (IC1) since SD cards are not 5V
> compatible.  If your 5V supply is out of spec, that would probably
> explain the issues you're seeing.  I'd meter out the 12V input and the
> 5V supply.
>
> -andy