Bitcrusher problems

Forum 2005-2010 (read only) Software Troubleshooting
1

hello all, im new to arduino and to this forum - i just completed my first Arduino project although i have been working with processing 1.0 for some time.

the fact that im familiar with the software side of things is particularly frustrating with the problem i have. I'm trying to build a bitcrusher device using these plans: http://www.instructables.com/id/Lo-fi-Arduino-Guitar-Pedal/

im making 2. i have one device fully working in stereo, no problems. the other, only one channel works - and the problem is with the arduino i think.

following this plan http://www.flickr.com/photos/james_nesfield/4654634360/sizes/l/, the left channel work perfectly. and the right channel has now sound whatsoever, not even a ground hum or anything. i have tried swapping the left and right inputs and outputs to the arduino and the situation at the arduino right channel output doesn't change, which leads me to believe that the problem is on the arduino board.

unfortunately i am not familiar enough with the arduino hardware, or environment to really feel confident about my problem solving abilities in this area, though i know what i want to do: i would like to swap all the inputs and outputs of the right channel to see if its a hardware problem with the arduino board - i just can't figure out how to do this in the software.

the code is here http://redirectingat.com/?id=487X782&xs=1&url=http%3A%2F%2Fvimeo.com%2Fgroups%2Fphysicalcomputing%2Ffile%3A418&sref=http%3A%2F%2Fwww.instructables.com%2Fid%2FLo-fi-Arduino-Guitar-Pedal%2Fstep6%2FUpload-DSP-Code%2F what i would like to do is change the input from analogue 1 to analogue 5, and change the outputs to some other pins, but i can't see exactly how to do this in the code - i didn't write it, and i can't seem to get my head around it yet.

any help solving this problem would be greatly apprecitated - i seem to have written a lot here, but i think the problem of swapping input/output pins in the code should be pretty straight forward, i'm just not seeing it at the moment.

thanks in advance for any help,
FJ

2

hey FJ, so the code is over my head as i have never done anything near that complex. But after giving it a quick look, it looks like on the "interface.h" tab there are the pins defined. i don't know what bitcrush, bitshift and such do, are they maybe inputs? you can change the numbers of them to the pins you want them to be (as long as they aren't already in use).
also there is the "dsp.h" tab that is left and right defined, swapping those might give you the change in output you are wanting.

again, i don't claim to know what i'm talking about, but that's what i would try messing with.

good luck!!

3

change the input from analogue 1 to analogue 5

#define left 0
#define right 1

becomes

#define left 0
#define right 5

in "dsp.h".

4

hey spooky, thanks for the reply.

i agree that pins are defined in the 'interface' tab, however these pins don't handle the audio, they are only used to control the parameters, but their code is quite simple:

#define redPin 9
#define greenPin 10
#define yellowPin 12
#define knobaPin 4
#define knobbPin 3
#define knobcPin 2

i think the audio pins are defined in the 'timers' tab, but their definitions look more complicated:

#define pwm3 OCR2B
#define pwm5 OCR0B
#define pwm6 OCR0A
#define pwm9 OCR1A
#define pwm10 OCR1B
#define pwm11 OCR2A

i can't find these anywhere else in the code, so im guessing they are specifically related to the hardware, but i can't find any info on the main site at the moment....any ideas?
FJ

5

hey groove, thanks for the reply - it seems setting the audio input to a different pin is quite straight forward, i had done what you suggest (though its nice to get some confirmation).....the problem now is the output - moving from pins 5 and 6 to two other available PWM pins....and im still a little stuck on that!
thanks again,
FJ

6

moving from pins 5 and 6 to two other available PWM pins

I think you've already answered your own question here:

#define pwm3 OCR2B
#define pwm5 OCR0B
#define pwm6 OCR0A
#define pwm9 OCR1A
#define pwm10 OCR1B
#define pwm11 OCR2A
7

yeah, i know im in the right area - i just want to be sure when im probem solving so i dont create more problems than i solve...

with these output definitions, do you have any idea how they are defined? all the other code i have seen it just a simple number i.e. '5' for pin 5 on the arduino board. here

#define pwm3 OCR2B

, the author has used something a little different, and i would feel more confident if i knew what was going on rather than just guessing.
thanks for your help so far,
FJ