Phlip has created a homebrew guitar tuner for the DS and needs some help testing it. If you are interested in this program and would like to help Phlip then follow the instructions below and contact him with you're results on the gbadev forums.
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I'm trying to write an electric tuner for the DS, but I'm having trouble with the timing. Namely, the timers in the DS aren't that accurate - they're well within the range you'd expect from a video game system, but to be accurate to, say, the nearest cent, the timers need to be accurate to ±1/20%... way more than the DS is designed for.
I'd like to think that, with enough calibration, this problem can be gotten around... but it depends on how consistent a DS's timer is, in the same DS... I know from a quick experiment in IRC that WinterMute's DS's timer runs about 2% slower than mine (it reports the sound as about 40 cents higher)... but on the few tests I've run on my own DS, it rarely disagrees with itself more than about a cent. If it's always about the same on a single DS, then running some sort of calibration the first time you run it should be enough.
This is where you need your help: Download the tuner. Put the .nds file on your DS and run it. Put your DS next to your computer speakers, and play the two .wav files in the zip. Post your results here. Specifically, the reading in the top-right of the lower screen.
Run the tests a few times, and see if you get consistent results... if possible, test it in the middle of the day, and at night... temperature might affect it, depending on how the timers work in the hardware. If all (or even most) DSs get similar numbers every time, even if they don't agree with each other, then the project can probably go ahead... otherwise, I'll probably have to scrap it, which'll be sad.
So yeah, the more data I have, the better, so if as many people as possible do this for me, it'll be great. I don't think I'm asking much, just run a program, and play a couple of sounds... should take 1 or 2 minutes, at most, at a couple of times during the day.
Oh, and one last thing: The program, as written, isn't particularly good for tuning actual instruments yet, even without the calibration problems... it's good for sine waves, and not much else. That'll get fixed before release... it's just got something in there right now that's simple and works.
LOL you are allowed to do whatever you want with this homebrew, but I think at this stage it's not an accurate tuner yet, thats why he wants people to do the tests for him, so he can calibrate it properly for musical instruments. But I am sure he would appreciate any and all input.
a440.wav +00c (the second zero was flickering slightly, but it stayed on 0) c523.wav +00c (second zero bumped up to 1 a couple times during the playback, very briefly)
Looks like a nice and simple little app. I hope it works out. The waveforms on the top screen look really nice. I tried it with my guitar and the meter was all over the place, so it looks like that´s not quite ready yet. Although it stayed a bit more steady with my voice than with the guitar. I assume that´s the timer issue you´re talking about. Anyway, I hope you can do something with it! I would definitely use this app.
for the c523.wav I got 523 +00c only the second Zero twitched a few times though
for the a440.wav I got 440 +00c only the second Zero twitched a few times
I think this is a very good app for the Ds and I would like to see this go far.The Oscilloscope on the Top Screen was a cool touch and I also needed a Guitar Tuner too
yeah i got it to work fine (only for sines) and even if you cant make a full tuner app, you could always release the oscilloscope as a separate project! thats reason enough for me to keep it.
also i used an old keyboard (not qwerty) that can output sine and i found that it was very accurate D3 and higher, even more precise in the upper range. keep up the good work, id love to see a real functional tuner i can have on my DS, it might help me tune timpani.
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Tue, July 24th, 2007 at 03:39
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and I also needed a Guitar Tuner too 
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