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I mean that I hope that Teensy 4.x USB MIDI (when Teensy libs are upgraded to MIDI2.0) will continue to work with MIDI 1.0 drivers and devices, so we can continue using old devices and "old" OS (I don't know what plans does Microsoft have for MIDI 2, but chances are that they won't release new...

Zipper noise occurs when you change a parameter of sound synthesis path such as oscillator freq, amp, filter cutoff, delay time, etc, in a "stepped" way. Analog signals are smooth, so when you turn say frequency knob in analog circuit the frequency sweeps in smooth way. When you control digital...

I just hope that MIDI 1.0 will continue to be supported. I have lots of hardware using good old midi that just work. Also I have my own projects that I use good old MIDI and 127 different values per potentiometer is more than enough (can't move the knob more precisely). Zipper noise is not an...

Simplicity. Embedded hobby projects usually don't have gazillions of files and name conflicts therefore namespaces are rarely used. Historically embedded projects did not use C++ at all because modern C++ with templates, std lib might bring bloat that is not really welcome when you need to...

Is beginning of the table guaranteed to have value of zero? Cosine for example doesn't. In such cases crossfading over single buffer length might be better.

Heap allocation is never guaranteed to succeed. Heap fragmentation is real thing and dlmalloc is not magical cure. I have seen it fragmenting memory too. So as long as you do hobby project, or music app that will just stop playing and you will just restart it once your allocator fails, you can...

Yeah.. Yamaha engineers implemented clever tricks to even avoid multiplication. Their custom FM chips did just additions and ROM lookups. The first ROM was a log-sin waveform table, containing one quarter of a sine wave, 256 samples long. The second ROM was an exponential table, 256 samples...

IMHO, a small FPGA might be a better fit for such a task. Or programmable state machine like PIO in RPico with its wait instruction.

Since my goal is to be able to play live as much music as I can, I implemented advanced arpeggiator and split keyboard feature and multi-timbrality. I also worked on some recreation of famous Solina String Ensemble sound. A little demo is here.

You just can’t help but love this ’80s vibe.:)

There is a technical note by NXP covering lifetime vs temperature subject: https://www.nxp.com/docs/en/nxp/application-notes/AN12253.pdf Expected lifetime drops drastically with the increase of junction temperature from 75C to 95C and there is a substantial difference between lifetime at 528MHz...

The other approach would be to fix measurement time and each core should be allowed to do as many iterations as it can within given time. Then the sum of number of iterations done on each core should be used to calculate total performance. This would address multiple cores of unequal speed. But...

Also benchmarks don't tell the whole story. FPU on ARM M7 (Teensy 4.x) seems to be pipelined better than on RISCV

That is very true..In fact ESP32-P4 does not seem to have any safety margin at all. Their 400MHz part can only run stable at 360MHz at least with currently available chips.

In my opinion it does not make sense to use overclocked results (at least for sake of comparison of different processors ) because overclocking is subject to silicon lottery and reliability is questionable. If comparison is meant to be fair, stock speeds should be used. Of course they might be...

There is a #define MULTITHREAD that must be defined via platformio build_flags to allow multithreading. For two threads: build_flags= -DMULTITHREAD=2

Single core ESP32-P4 @360MHz result ( -DMULTITHREAD=1) CoreMark Performance Benchmark CoreMark measures how quickly your processor can manage linked lists, compute matrix multiply, and execute state machine code. Iterations/Sec is the main benchmark result, higher numbers are better...

Are you using Platformio by chance? If you have ESP32-S3 code/project I can run on newest ESP32-P4 and post the results.

Exactly. Getting Teensy in Europe was expensive already (shipping). It is quite absurd that two good companies can't just talk. Adafruit has done a lot of good stuff and Sparkfun too. There is a place in the market for both. Really people maybe you should meet in person and drink a beer or two...

I call myself a hobbyist (even though I have EE degree) and bought plenty of Teensy 4.x and going to buy way more ! @ptorrone - initially I wasn't understanding what this is all about, but after what you have said and done it become clear that there is some thing going between you and Sparkfun...

Quite frankly I find it strange that supplier like Sparkfun does not want to sell their products to anyone who wants to buy. It is business. Just leave your egos at the door and get back to business. I guess that the whole drama wouldn't happen if PJRC continued to manufacture Teensy 4 by...

The confusion might come from the fact that it might not be classic 7805 linear regulator, this part on the schematic has symbol of K7805-500R3LB. When I searched for it it looks like switching regulator that is "replacement" for 7805, but might come in non standard package. For low noise...

Super cool :) Hall effect sensor rulez !

I second that. Having no sleep with a newborn can be really exhausting.

Using two 2.5 MOhm resistors (R1,R2) as a voltage divider creates a Thevenin equivalent resistance R of 1.25 MOhms at the non-inverting input. While this consumes very little power, it is generally not recommended for the LM358 due to its bipolar junction transistor (BJT) input stage. Noise...

For what it is worth, I also purchased ESP32-P4 and actually tested on my own and it runs circles around previous S3 model even at current 360MHz. But quite obviously it is slower than Teensy.

With great respect to PJRC and all the great work they do, I’d like to share a personal humble opinion. I think PJRC’s real strength is Teensy itself: high performance, small and easy-to-use hardware, and excellent custom libraries. That focus is what makes Teensy special. WiFi and similar...

Thank you very much for the response. Can't wait to see the magic again :-)

In the light of recent discussion about "open source Teensy" I would like to ask @PaulStoffregen if there are any plans for new Teensy 5 from PJRC based on 1GHz NXP i.MX RT1170 or maybe other 1GHz microcontroller such as Renesas recent offerings https://www.renesas.com/en/products/ra8p1 now in...

There are plenty of boards with lower performance and similar form factor and cheaper. RPico2 and all clones. Lots of Chinese STM32H503/H523/H562 and STM32U585 low power "pill" style boards, these are new, dirt cheap ARM M33 with floating point and 160-250MHz clocks. This mid performance market...

Yes, but they are Linux based. I need bare metal, without Linux interfering and adding latency, long boot process and host of other stuff I don't need. Teensy is just perfect. If only it was faster. I was hoping for 1GHz NXP part (NXP i.MX RT1170) for a long time. Apparently the other 1GHz...

For perfectly smooth ramp, you would need to adjust volume on sample-by-sample basis.

FWIW: there is browser called "Supremium" (Chrome based), that implements its own HTTPS stack independent from OS and allows to browse modern sites on Win XP without headache. I have to agree that Windows is really good in maintaining compatibility

But ESP32-P4 has hardware (single precision) FPU and it is 400MHz dual core part.

I am doing crazy amount of multichannel audio DSP real time, including real-time analog circuit simulation (nonlinear differential equations).

Personally, I need more computing power, so I would welcome microcontroller in the 1GHz range. Anything less than that is step back compared to Teensy 4.

I’m sorry to hear that things have taken such an unfortunate turn.

I want to understand your situation @ptorrone . So you are authorized reseller of Teensy and you were rejected by Sparkfun from buying from them? Did you try buying from DigiKey? They have Teensy's in stock and I am pretty sure that they will be more than happy to sell them to you. I tried to...

But the default value of off_velocity parameters is incorrect. Should be 64 as per MIDI spec.

Variable frequency is not a problem (you can crossfade between wavetables from different octaves), however, the triangle with variable duty cycle that can degenerate to sawtooth-like signal requires approach described here: https://www.kvraudio.com/forum/viewtopic.php?t=618161

Yes, it is dual core but each core is 150MHz. So as I wrote before it is 2x150MHz. It is HALF of performance of Teensy 4 and it is more difficult to program as when you really need those CPU cycles for single really complex real-time calculation, single thread programming is conceptually way...

The easiest way is to use bandlimited wavetables for each octave. You can generate bandlimited wavetables programmatically using JScript sample below and store them in C arrays for direct use in your program. https://jsfiddle.net/s9ydpzjn/

DAC performs antialiasing during conversion to analog but this does not eliminate the need to properly antialias generated waveforms as once aliasing happens, it can't be "taken back". For example pure "saw" waveshape has infinite harmonics. If you don't apply bandlimiting, those infinite...

Pico2's RP2350 (2x150MHz) is still HALF the speed of Teensy 4 (600MHz), has half RAM (520K vs 1M for Teensy) not to mention that Teensy 4 is way easier to program, so Teensy still has all advantages except the price.

According to this discussion https://github.com/jackaudio/a2jmidid/issues/14 it is equivalent to release velocity = 64

This is key release velocity, some keyboards report that and some synths (like Virus TI) can interpret that value to adjust for example release time or any other parameter via modulation matrix.

As I understand it, the audio library uses DSP instructions https://developer.arm.com/documentation/100166/0001/Programmers-Model/Instruction-set-summary/Table-of-processor-DSP-instructions for speed, not for accuracy. Some of the instructions operate on 16 bit data to allow 2 arithmetic...

Some early videos are here (the thread is focused on my polyphonic after touch keyboard, but the sounds come from that teensy synth) https://forum.pjrc.com/index.php?threads/velocity-sensitive-contactless-midi-keyboard-with-polyphonic-aftertouch-for-teensy-synth.75078/post-363847

FWIW: I have 16 voice polyphony, each voice 3 band-limited polyblep oscillators, 4 envelopes, 3LFOs, two ZDF filters with nonlinear saturation, flexible mod matrix, effects units all running on stock 600MHz Teensy 4 all in floating point written from scratch, no audio library. So it is not a...

FWIW: PolyBLEP requires floating point for those polynomial based step corrections, even if the rest of oscillator is integer based. Come on it is nearly 2026 and Teensy 4.x can do single precision floating point almost as fast as integer. The library should move to floating point for quality...