mleibman

Most recent activity

• A follow-up to Puck.js?

  @mleibman started

  • 10 comments
  • 5,972 views

  @Gordon replied
• Espruino Shop (and Pixl.js preorders)

  in News • 5 years, 12 months

  

  I ordered the MDBT42 module, but then realized that it'd be pretty useless to me without the breakout board. I saw it on one of the product photos and assumed that it'd be included, but now I don't think that's the case.

  

• A follow-up to Puck.js?

  in The Place for Patreon Patrons • 6 years

  

  Nice, thanks!

• A follow-up to Puck.js?

  in The Place for Patreon Patrons • 6 years

  

  Can you share some more details on the Pico-style board with BLE?

• Slow FFT on Pico

  @mleibman started

  • 4 comments
  • 3,055 views

  @Gordon replied
• Slow FFT on Pico

  in Pico / Wifi / Original Espruino • 6 years, 1 month

  

  I see... that's a bummer. I really like the Waveform's ease of use and was hoping that it would provide me with the best of both worlds - a convenient JS code for doing some light post-processing and output, coupled with an efficient internal implementation.

• Slow FFT on Pico

  in Pico / Wifi / Original Espruino • 6 years, 1 month

  

  I'm trying to experiment with audio analysis on the Pico and am running into slower than expected performance.

  I've specifically picked this board because it runs on the Cortex M4 MCU with accelerated DSP via CMSIS. (It is unclear if it has an FPU, but I'm not using it here, so...) I've run some timings and am getting ~44ms to run E.FFT() on a 128 16-bit data:

  var w = new Waveform(128, {doubleBuffer:true, bits:16});
  var a = new Uint16Array(128);
  
  w.on("buffer", function(buf) {
      LED1.reset();
      var l = buf.length;
      a.set(buf);
      var start = Date.now();
      E.FFT(a);
      console.log(Date.now() - start);
      LED1.set();
  });
  
  w.startInput(B1, 44100, {repeat:true});
  

  At best, this is 1000/44 = 22.72 FFTs per second.
  According to benchmarks done in http://openaudio.blogspot.com/2016/09/be­nchmarking-fft-speed.html, Arduino M0, which has a slower chip with no DSP unit does 639 FFTs per second, while a Teensy 3.2, which runs a similarly specced NXP chip manages 7156 FFTs per second when not using accelerated DSP and 14286 when doing so.

  So, what's going on? Am I reading it wrong or calling it wrong?
  I get that their benchmark is in C while Pico is running interpreted JS, but E.FFT() just calls into the C library function, so there shouldn't be much overhead there. Looking at the GitHub sources, I do see that on the Pico, E.FFT() supposedly calls into CMSIS, so this should be really fast.

• A follow-up to Puck.js?

  in The Place for Patreon Patrons • 6 years, 1 month

  

  Thingy:52 looks very interesting, but I agree that it's really bulky.
  Either way, I look forward to Espruino being supported on more platforms.

• A follow-up to Puck.js?

  in The Place for Patreon Patrons • 6 years, 1 month

  

  Gordon, thank you for your contributions!
  I've just recently gotten into Arduino et al. and have gotten a Puck.js - what a fun little device, and a JS-based web IDE is so easy and fun to use.

  Do you have any plans for a follow-up? Ideally, something a little more powerful and with some more built-in sensors (IMU) and connectivity, while retaining a small-ish size and being wrapped up in a neat little self-contained package.