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I cloned the Teensy4_USBhost library and added my CDC and audio drivers plus a test sketch. The CDC driver is M8_serial which I created by hacking up the CH341 driver. The enumeration code was generated by ChatGPT and I pasted in a few other things from a ChatGPT generated driver that didn't...

Thanks for the reply. I tried setting DTR and RTS active by default in my driver thinking that the device might be expecting that but it didn't help. I didn't try fiddling with that with the CH341 driver. I'll take another look at the CH341 driver to see if I can figure out how bulk messages...

This library was exactly what I was looking for - the ability to a host audio device with a Teensy. ChatGPT wrote an audio driver for me and as far as I can tell its working! The device I want to use is composite with audio, MIDI and CDC interfaces. Its a Teensy 4.1 USB device but I don't have...

This looks promising: https://github.com/Averyy/esp-uac2-host MIT licence. Would be great to have USB audio supported in the T4 host library.

Just noticed the question Re: developments. I have played with the library quite a bit and it works very well. There are still a few things that don't work correctly (resonators as I recall) but the majority of the DaisySP library works. The official DaisySP library has lost a lot of...

That would be great! As you may have noticed I did a port of DaisySP to the Teensy Audio library. I'll keep flogging away at it.

Very cool algorithm by Joel de Guzman: https://www.cycfi.com/2018/03/fast-and-efficient-pitch-detection-bitstream-autocorrelation/ He tuned the algorithm for guitar but no doubt it would work very well for other instruments. It detects pitch within 2 cycles (or less) with a very high degree of...

Thanks for pointing that out. The compiler keeps it straight but it is confusing to a reader. I just pushed changes to the example sketches. Its trivial to set up the Teensy Audio library for DaisySP so you don't really need the Audio designer. DaisySP does almost everything the Audio library...

I wrote a 16 voice polyphonic synth example for the DaisySP library. https://github.com/rheslip/DaisySP_Teensy/tree/main/examples/polysynth each voice has: 4 polyblep sawtooth oscillators 1 moog ladder filter 1 envelope generator which controls voice amplitude and filter frequency plus mono...

This is kind of a hack but it works - DaisySP as a Teensy audio object. DaisySP is mostly code ported from other projects - Csound, Soundpipe, Mutable Instruments eurorack modules etc. There is a lot of neat audio processing stuff in there that the Teensy Audio library does not have. Editorial...

Nice project! I did something along these lines - an HF SDR transceiver which uses a Softrock kit for the radio part and the Teensy for audio processing. Similar approach but the Softrock is direct conversion with I/Q in and out. My experience with the audio libraries is very similar to yours -...

I think you can do this already - the link from object to object is a pointer and there can be multiple pointers, I have been thinking of writing a selector object that works the other way - select one of n inputs to a single output. I need this for my software defined radio project. For the...

Pete - I'll PM you the Hilbert filter code. I've been trying it this morning and it works every time. Maybe something is flakey in the hardware or some code corruption in the loader? Its pretty weird. Rich BTW - I have a working I/Q version of the SDR RX. It uses the same Hilbert filter code...

Something strange happening with the FIR filter. I have set up a Hilbert Filter pair to generate a 90 degree phase difference between the two audio channels. I have confirmed that it works, and yet sometimes the filters behave as tho they are in passthru mode - no phase change. I can compile...

FIR filter optimization Just noticed something of interest in the FIR filter processing block. There is an arm_fir_fast_q15 function in the ARM CMSIS DSP library that uses 32 bit accumulator instead of the 64 bit accumulation used in the arm_fir_q15 function that's used in the audio library...

A suggestion for the library: I have an application (software defined radio) that requires separate FIR filters for left and right channels. I have it working but it looks like when you call AudioFilterFIR it automatically creates left and right filter pairs. It doesn't look like it processes...

Presumably you've modified the library and the old sketches to assert/deassert all the SPI chip selects correctly before anything gets initialized. Fiddling with SPI modes has to be done very carefully when there are multiple devices. I used soft SPI with the TFT display I was using because the...

>> But if I run the PlayFromSdCard sketch, none of the sketches using flash will work after that. Perhaps the flash chip requires a different SPI mode ? Wrong mode can actually work but be right on the edge timing wise. Rich

Sure Rich

Pete. The spectrum is correct - double sideband suppressed carrier. I saw clipping with my scope at the line out pins even with the volume set to 20. There are multiple places in the codec when clipping could occur tho so its probably due to some internal gain. Your test is right at the limit...

Pete That definitely helped. When I scale using >> 15 output level is much better. If I multiply two sines I have to scale them to about 0.8 or the result clips which seems a bit odd. Above about 0.7 the sine output of AudioSynthWaveform clips regardless of the volume setting. I should be able...

Yeah - so actually it should be >>14. I used a 13 bit shift to scale the output 2X and I didn't see any problems with it. It will clip if you multiply a square wave by a sine but sin**2 for example yields a fairly small output as does sin * audio which is what I'm doing. You can scale the inputs...

Attached. Still pretty hacky. I included multiplier.cpp, multiplier.h and audio.h for the audio library. Note that when I scaled the multiplier output there is an extra factor of 2. It will clip like this with full range inputs but I found the output level to be more useful for most of the...

Just joined the forum. Got my Teensy and audio board the other day and I'm really impressed. Paul and the rest of you have done a great job on the audio library. My interest is in making a Software Defined Radio. I hacked away at it yesterday and a crude version of it is working. From what I...