I am trying to make a guitar loop station. For people who dont know its a device that records what you play on your guitar and outputs it to your amp while looping it. I want to be able to record multiple loops over each other (dubbing) and i was going to use a chipcorder to do the recording. I was wondering if i should go with the board that has the SPI interface and replace the chipcorder with one that holds more audio or go with the board that has the tact switches. If i went with the board that has SPI, which i think is the way to go, how do i interface it with the arduino?
thanks for whoever found anykits.com, huge help for this project
It looks to me like option 4 can repeat several recorded sounds one after the other, but not overlay them.
I also suspect that the audio quality will not be that great - I'm not sure where you plan to use this thing, but I suspect that the quality will not be good enough for any public playing.
I don't think you can do this without a decent amount of ram and a processor that can access the ram quickly - I think an Arduino is out of the question here.
A few years ago I was looking at doing some guitar effects. There was a little DSP evaluation board around at the time which I looked at. You might want to look in that direction. It will also open up the possibility of not only doing dealys, but other effects, too.
Thanks for all the responses, i dont think that i can handle the costs or the programing for something like that DSP eval board. If i was to build this i would just be using it to jam along with my self so audio quality is not too big of an issue. One more suggestion before i give up and go buy a RC-2 (which are only $180). Would it work if i bought a chipcorder chip for each track i wanted to over dub with? I would only use 5 tops but i could get by with 3, i could build the recording boards and then trigger the switches with the arduino. Would this work??
You could trigger the switches with Arduino. But the big problem would come if you still want to layer sounds. It would probably be possible to set up a switching scheme where you could control one chip to record what another is playing, but i see some mixing issues because you would have to mix that signal with what you are playing. Before you had everything working it would probably cost you quite a few $$.
If you have a decent PC you could check out the Moebius (or is it Mobius ?? google it !) looper software, which i think is free for non commercial use. I'm at work right now so i don't have a link to it here.
It's probably possible, but timing would be an issue, and you would have to find a way to route the guitar signal to the chip corder that is recording, and that could fast become hairy. Switching audio signals is not easy without lots of pops and clicks. And controlling the routing of an audio signal in a " one to many" setup is not easy. Especially if both your hands are tied up playing the guitar.
well thats where the arduiono comes in. id have footpedals to control the recording playing and erasing. but what would i have to do timing wise to the chips?
I don't know the deatils of the chip corders so i can't really be of any help with the timing. But you would somehow have to make sure that the ones playing are started at the same time as the one recording. At the same time you should somehow route the signal from the guitar to the input of the one recording.
Arduino is pretty fast so if the Arduino board is controlling the switching the timing might not be a problem, but you still have to tell Arduino what to switch and when, and your feet are much slower
There's a few considerations you need to take into account if you want this to work well: The following is my recommendation for the pre-sampling - using this allows you to interface quite easily into whatever kit your implementation relies on
First off, it would be easier to use separate AD/DA converters (2 or 4 - you dedicate each converter to handle a slice of the input band .. for a guitar, i would suggest ad1=30-440hz, ad2=441-1260hz, ad3=1261-4400hz, ad4>4400hz - remember, the lower frequencies have greater gain, slicing it up helps preserve the band equalization) with a small built in buffer (say 16k) .. you could FIFO the buffer into an external buffer (you'd need at least 128KB if you want, say up to 2 seconds of audio at 192bps).. The AD/DA converters are built for stuff like this...I'd also suggest to build a small analog mix circuit to mix the guitar output with the sampling audio as opposed to everything being coverted to digital to avoid latency problems.. Then use the arduino as the transposer for driving the input/output delay ratio and to control the buffer timing (flushing the converters to the external memory block across your bus). Lastly, you need to construct it to isolate the clock frequency harmonics from bleeding into the output (if you care about audio quality).. If this is a project you are doing for fun, then great.. If it's something you are building just because you need it, then just use protools with the digital sampling/delay plugin... (btw, there are chips that do ALL this for you. Check out 1Y8839 or the 32H9010 (sfm) both from CampusLabs, ~40$ and ~90$ respectively)
-Eugene
alright
i think im gonna go for it and maybe enter it in that arduino contest coming up at the end of april
