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would using & 3 reliably cycle an accumulator? Usually in my sequencers and oscillators the core is an increasing value using: "phase = (phase +1)%length" I am wondering if & would work as a drop in replacement for % in these? Seems like & would be a huge potential performance gain overall.

By the way, sending intermittent chaos to an old screen can cause some very interesting glitches. One in particular has me very curious. I am not aware of anyone having made this display work in multiple levels of greyscale, but Ive gotten smooth grayscale gradients from the glitches at times...

Yes; so far this has been the only tricky bit I am still hung up on. I've been trying to find the proper/clean way of setting up the trx.busy to be able to belay any other potential SPI communications or else "^&$^(%&)‚fl°‡··‡fl·°‡fl·°flfi››—€....." Any good resources on setting this up you are...

Oh also, if you are brave, I have a technique on the FV-1 DSP chip assembly language that only requires about 6 instructions to create a sine and cosine wave. I believe I posted it somewhere on the forum but here is the FV-1 code: equ oscSin reg0 equ oscCos reg1 equ oscFreq pot0 ;reg2...

I have some techniques that don't take too much CPU but only work for specific circumstances. What is your planned usage? I might be able to help. Also, @PaulStoffregen is right and I might suggest an option in that light: "A sensor in a musicians shoe" Or rather, a tap tempo button. If you...

You can totally make an array of audio library objects, I did this for a quad FM oscillator test years ago. if I recall it was just a matter of creating the audio objects as : pseudocode:: AudioObjectSine SineOsc[32]; and then addressing them like you were trying before but with regard to...

I have noticed for a while now, when I upload a sketch from arduino through the little teensy uploader applet, it has to be at least partially visible on the screen to complete the upload, otherwise arduino IDE gives an error that the teensy failed to respond. Would it be difficult to make this...

The DAC writes do not have to be done at regular intervals, but it does make things sound a bit better if used as direct audio source. I have 2 implementations of my DAC writing function that I flip back and forth between in different scenarios. One is an ISR driven by IntervalTimer, and the...

I have one critical question, I have most of what I need set up to do partial screen writes in my DMASPI Display method now, but I realized the Transfer didn't have a way to offset the position into the buffer for the partial write. What would be the best way for me to go about this? I will do...

I will look into that if the need arises. Thank you for the hint :P Its not what I would call highly critical. Before, was plenty fine for its intended purposes without DMA, but there were little moments with the scope zoomed in that you could see the DAC holding for a couple ms while the...

Oh nice! I added an ActiveLowChipSelect object with my appropriate 32mhz spi settings along with a couple other tweaks streamlining the commands prior to the DMA transfer and I am getting 400us loop time. thats almost 2x faster than my non DMA writes. Still using the while(busy) to hold...

RE: the 2000+us with DMA vs 760us using regular SPI / activelow chip select. Ill try using the recomended chip select object out right now and see where I get. That makes sense it would help to have the CS and SPIsettings wrapped in a DMASPI abstraction, but I couldn't seem to figure out what...

tried the aforementioned technique of moving the while before my transfer and stuff flys of the rail because of the other screen commands used to set up the screen for receiving data, and if I move it before those commands, it seems as though the screen never gets any data but the timer showing...

is it possibly taking time waiting on potential input from the SPI? If so, is there a way to only send and not worry about any receiving? alternately, could this have anything to do with the 8bit transfers vs 32 bit DMA hardware?

Currently transferring using dmaspi with a while(trx.busy())){} afterward takes longer on my OLED screen write tests than SPI.transactions. 2000micros vs 760micros any ideas why? #ifdef DMA_PAGE_TRANSFER trx = DmaSpi::Transfer(buffer, BUFFER__SIZE, nullptr)...

The touch screen board link doesn't seem to work. I have a few ideas on layout if you are open to them. DMA and SPI is a very good thing to be considering at this point. Also huge is possibly using parallel screen communication rather than SPI, though I don't know yet much about how to...

Ive been considering doing an open source utility project of this nature as well, I would love to make it a collaborative effort. You know I'm a fan of you mxxx ;) and the OC code now is incredible, and builds a fantastic inner platform for apps. what I have been designing as a concept for...

What did you end up using to make this? I also tried a bajillion things to make or convert fonts and wan't happy with any of them :/

is there a simple example of how to use the DMAchannel library? I really want to try adding DMA in my screen driver, but I need a simple example of where to start. I have been looking at the Ornament and Crime module code on github...

This is a pretty nice interactive java applet that gives a little bit of insight on how the DFT/FFT process works. I have some other learning material that I found quite useful and will gather that here. http://mathlets.org/mathlets/discrete-fourier-transform/comment-page-1/#comment-12099

Is anyone else having issues loading the doc? It gives me an error that appears the file is looking for an E: drive in my file path that isn't there. Somehow I had it working from an older version of the library but the update will not let me move around in the HTML doxygen doc

Hahahahaha nice user name ;P

I think the wording as it was is pretty clear. If anything I think the addition of some diagrams may help people understand some of these things, such as a picture of a sine wave > gain of 0.25 / gain of 1.0/ gain of 2.0 with clipping and maybe even one with two signals causing clipping when...

I am reading your code to get an idea of how to do things, but writing my own from scratch only using it as a reference. I had this interesting idea to make a multifunction DSP buffer object that will be insanely flexible with methods that allow configuring it as a variable delay with or...

Teensy is the euro core :P

I have this for RAW, did you guys get it good for WAV? we need to start pull requesting all this useful stuff and get it into the bistro.. there are many cool and extremely useful objects now that are floating through the forum..

@pensive compressor design is kinda tricky, I found that you really have to dig into linear vs log dB scaling and different averaging schemes for the attack and decay, I made a pretty good audulus implimentation so I can likely port that to teensy soon enough. I think my plan right now is to...

Im also curious about the buttons! Great work! really nice design :D any more info available?

@Jp3141: Very interesting, do you know of any resources I could read more about this issue or what I might google to find more? I haven't had any issues yet in my tests but most of them are using multiple oscillators for FM/amp/ring modulation. Also wondering if you know if it is possible to...

Here is also a thread about it on the FV-1 forum that explains a bit more http://www.spinsemi.com/forum/viewtopic.php?t=523

It is compared to all other options like bit shifting or look up tables etc.. especially when you need to do it as quickly as possible to allow as much audio generation/processing as possible in a small chip.

division is super processor heavy.

I've been working on a project using the teensy/audio and FV-1 effects chip, and in the process I am learning many efficient techniques to make assembler dsp code for the FV-1. I just found a sine/cosine oscillator technique that uses only a few multiply/accumulate and registers to create a...

I think for the impl, it might be more user friendly to boil things down to set. Also I had great Results in my tests using only the built in buffer and SD card for recording, the only issue was I had to generate a whole reversed version of the file to have smooth reverse playback, so I am...

a few questions: what is the m_ before all of the variable names in the library for? what does it mean/stand for? what is impl mean in the names such as "set_bit_depth_impl" ? also, are your current settings using all of the internal memory available? I think I may modify this to work with...

Would you be willing to provide your code and post it to the audio library? I am working on something that I want to be able to use the FFT to analyze on demand without taking up CPU when it is not needed. In general I would like to add a way to disable objects directly without needing to add...

I made the library modifications and I still can't seem to get anything out of this. I tried modifying the test to use the line input but nothing seems to come out. Also Avi Harel: The free verb all pass are supposed to be all pass delays, not all pass filters. They are basically a delay...

Sick! I'm going to check deeply into this for something I'm working on! Good work!

What screens are planned to be supported?

what is this new github commit mentioning USB-IO? is this in development or is it available for experimenting?

H3ll yes mykle, I'm gonna look into that. I keep wondering if the Faust route is the best for portable DSP, and I think it might be. I just wish I could program it more like Pd/max in a graphical flow method. Maybe if I make a bunch of modules for the audio lib. But my main concern that I am...

On this topic, I am wondering how rapidly the biquad coefficients can update? Do the coefficients have linear interpolation or anything to avoid popping? How about clearing them if something goes haywire, is there a clear command or would setting the coefficients to 0 for a moment do that...

Wow, that would be amazing, a phase vocoder on the teensy. That is one of my favorite algorithms. There is a phase vocoder pure data patch in the built in example library that only takes 2-3% cpu on my laptop, however it does the analysis first and then allows playback of the analysis buffer...

the best way to do this is by modulating the time of a short delay effect and listen to only the wet delay. There is an artifact that happens when you change delay times smoothly that causes the pitch to bend up and down along with the delay time. teensy has a 4 tap delay object, but i am not...

I want to compile and try, I just don't know where to start, there are so many files in here and as far as I can tell none of them are arduino sketches so I don't know exactly how to go about compiling and uploading to teensy I agree, not to mention his other modules, I am down to work on this...

https://github.com/modlfo/teensy-braids says its 2 years ago, never saw/heard of this until now. I am wondering if it works and how to go about playing with it. I have the official store bought braids in my euro system and its one of my favorite modules by far, I would love to hack it or make...

I have been considering the idea of how to add a dedicated DSP chip to the teensy for processing more calculations. I am wondering if anyone has any recommendations on what reasonable priced/power/capability DSP chips are out there these days? I have been checking out the SHARC as I remember...

Actually, I think STK might be portable enough to work. STK functions just deal with individual samples, it could potentially be pretty simple. I am dedicating more of my time to learning how to make/edit libraries and work with deeper C++. I am currently studying the PureData LibPD for...

so is granular_bank an array that stores the buffer for the audio to be granulated? is activate a 1/0 boolean to turn it on/off? and I assume playback_rate is a ratio where 1 would be regular speed and 0 would be stopped, is it different in the freeze vs shift? like would shift use the...

Would you be willing to post an example sketch? I copied the two files but not entirely sure where to start with testing them, or how to use them. At least a general explanation of use?