tomas

Did anybody measure actual round trip (or one trip) latency of this under Windows ?

Amazing job!

New DSP|Power boards arrived and i discovered i could actually make the external 3.3V supply in a more proper way, without any tricks with LEDs supplying voltage to the VBAT. I'm using the TPS63001 buck-boost DC-DC converter to keep the 3.3V...

While i'm waiting for the new PCBs, i tried to make some music and a short introduction video for the project. Again, the TGX4 is the main source for all the guitar sounds, plus a few external pedals

More power related adventures: the idea from the post above is basically scrapped. Everything works very nice until such a power bank system gets near an electromagnetic guitar pickup, especially a single coil one as used in this guitar. It's...

The drone synth and the preliminary version of the looper in action. Amp/cabinet sim and effects (delay, reverb) are also Teensy based (TGX4).

Power section and related adventures: for the power section i went with the IP5328 power bank controller chip, mainly because it's a compact one chip solution to get multiple fast charging protocols and a stable 5V output. Plus the IP5328 chip...

Visually it's pretty much finished. The only hardware part requiring more work is the battery. The power bank will be replaced with two 21700 cells with charger/5V boost board based on IP5238 with I2C and few other signals exposed. Teensy will be...

this project has been in the works for over a year now. The guitar is based on an DIY kit (Harley Benton JA) which is heavily modded and upgraded, mainly with electronics. Hardware design is split in three main parts: 1. Pickguard, a large PCB...

> It is not mainly the codec but ground issues, or digital noise coming into the signal. In one setup a connection to a display gave a lot of trouble. Exactly that. I can confirm that popular China SPI LCD displays are super noisy. I was...

Hi, In my experience it is difficult to keep noise low for guitar fx, because of the extreme dynamic range, if you have a lot of OD and compression in the software. It is not mainly the codec but ground issues, or digital noise coming into the...

As a learning tool AI is actually good. It really makes you progress faster in learning. And I think that learning is actually one of very few good uses of this technology. What I am not comfortable with is calling entirely AI generated code as...

…but not, I hope, short circuited… Looks like it might be one of these. $200-ish, and only 8 bit, but a lot of low-end ‘scopes are only 8-bit (albeit with moderately decent front ends). Pity it doesn’t have FFT, though. Are you using 10x...

FWIW, I actually ran the code before I posted and glitch-free audio attached to post was generated by exactly this code and PCM5102 and analog output was recorded. But generally I agree that adding more buffers won't hurt :-) especially when you...

To verify that hardware is working properly, I suggest you try some basic code like this: #include <Arduino.h> #include <Audio.h> #include <Wire.h> // GUItool: begin automatically generated code AudioSynthWaveformSine sine1...

PCM5102A is perfectly fine. I am using it. It produces no noise if fed with proper audio input. In fact it is better (less noisy) than Teensy 4 audio shield. Unless you have faulty part (that might happen), that is not the issue with DAC. Noise...

I guess this is kind of "tiny" scope like DSO138 ($20). FWIW: that is not really a tool to observe and analyse output of 24 bit DAC. Anyway, do you actually hear the noise, or you are referring to "noise" to what you are seeing on the scope? If...

Did you connect SCK input of PCM5102A to the ground? Also full scale square or saw without band limiting in software would cause builtin FIR reconstruction filter to apply ringing at the edges that might get distorted (hard clipped) and be...

Cool chip. 24 bit SAR ADC is quite an achievement

Are you sure that you would get interrupts @24kHz, not 48khz with half empty FIFO interrupt? Keep in mind he is using 32 bit and stereo (i.e. 2*32bit), so 2 FiFO entries per sample. 384/(16/2)=48kHz

Don't forget the 32-deep FIFOs on the SAI transmit and receive. If you half-fill / empty those (16 samples) at 384ksps, you could reasonably do so under interrupt (24kHz) with a latency of 41.7µs, and without getting into the complexities of DMA...

You should rather use DMA to transfer data to I2S in blocks (say 128 sample blocks) rather than servicing I2S data register from interrupt directly. With DMA you would get interrupts much slower at rate of sample_rate/dma_buffer_length. You would...

Nice. But it should use float, not double. Float is sufficient(SNR > 140 dB). And use sinf().

Could you share exact part number of ADC chip?

In my project here https://forum.pjrc.com/index.php?threads/velocity-sensitive-contactless-midi-keyboard-with-polyphonic-aftertouch-for-teensy-synth.75078/ I am using neodymium magnets (small ones 4mm diameter) and analog hall sensors, the...

It’d actually cost more I/O to use the MCP23S17 interrupts than to poll the SPI bus! Plus, it only takes a single 32-bit transfer to read one set of 16 inputs; at 10MHz, the set of 8 will be done in 25.6μs (plus any overhead). You may as well...

For the reed switches if you have a 'scope you can investigate exactly how they behave and figure out a good debounce period... Without a 'scope you could write some Teensy code to measure the bounces even... Thinking about the scanning, you...

Hi all, I'm converting a vintage home organ console (Conn Serenade 632, 2 manuals of 61 keys each, plus a pedalboard of roughly 25-27 pedals and an expression pedal) into a MIDI controller to play through Hauptwerk or GrandOrgue. The original...

FWIW: Just a bit of history/trivia: Famous DSP processor Motorola DSP56000 and its successors had 24 bit data word, 24*24->48bit hardware multiplier and 48+8 (56 bit) accumulator to store results of multiply and accumulate instructions with 8 bit...

You are making assumptions on what he did and what he didn't. What he actually wrote is that he "asked Claude to make one". There is no mention of iteration of any kind, and even if he indeed iterated prompts, iteration alone is also not enough...

The prompt alone, no matter how creative it is, is not enough. https://www.copyright.gov/ai/ai_policy_guidance.pdf Direct quote So I would worry if I used AI to produce entire code for me, but frankly I don't care, I am not using AI to write...

1. MIT license is NOT equal to "no copyright". "No copyright" is equal to public domain. You don't have any rights to AI-generated code, therefore you can't assign the license. Slapping an MIT License on it has no legal weight because there is...

For the record: I am professional C++ developer with 30 years of experience. I have great deal of problem with code entirely written by AI/Claude. Anyone can prompt AI to generate code and it will come up with something more or less "working"...

See the source: https://github.com/PaulStoffregen/Encoder/blob/c7627dd2fea62b3585154e430f3c036653a5c745/Encoder.h#L82-L91 if INPUT_PULLUP is defined it uses it. You can also just call pinMode with INPUT_PULLUP yourself.

You are aware that mechanical chatter (bouncing) in switches far exceeds 100us, aren't you? Typically mechanical switch bounce time is >1ms. https://www.allaboutcircuits.com/technical-articles/switch-bounce-how-to-deal-with-it/ Expecting 100us...

You forget that a slow moving signal to a logic input may make dozens or hundreds of transitions anyway due to the high gain of an input buffer - the simplest way to handle the bouncing is poll the signals at a sensible rate like 1kHz - then high...

There are 3 separate cases: 1. You do NOT need any caps, if you are using hardware quadrature encoder inside NXP i.MX RT1062, as hardware does de-glitching for you. (RT1062 manual chapter 56) 2. You also do NOT need any caps, if you are using...

Yes, it definitely needs fine-tuning on case-by-case basis as reading largely depend on release distance from magnets and their travel distance. PolyAT is tricky. It depends on rubber/felt material and how "deep" after touch zone you want. In my...