Search results

  1. M

    Stereo guitar/bass cabinet emulation

    I'm tempted to build one as well! Nice work!
  2. M

    Stereo guitar/bass cabinet emulation

    Insane piece of work! You have managed to squeeze so much out of the T4 with this project, I'm really impressed with the results Marc
  3. M

    Stereo guitar/bass cabinet emulation

    ...or I can contribute fixes for those minor issues? @Pio let me know if you think it would help
  4. M

    Stereo guitar/bass cabinet emulation

    I followed Steve's suggestions and I'm now getting better results out of my TGA mkII board. Doing the offset calibration after a few minutes did the trick. I'm running into a few compile issues with the Arduino versions; I might give up on it and switch to PlatformIO, at least for this project Marc
  5. M

    Stereo guitar/bass cabinet emulation

    Here's what I get with both #define MEASURE_CODEC_PERFORMANCE commented & uncommented (I let it run for +5min each): ... Accumulator: 0 RAW RMS: 4.11 AudioEffectRmsMeasure: the RMS figure is -78.03 dBFS over 345 audio blocks ... Is this representative of what you get with your boards in...
  6. M

    Stereo guitar/bass cabinet emulation

    Yes, I'm using your library While doing the calibration eliminates the DC offset from the I2S input, however if you feed it with a full scale signal, you'll see that it begins to clip much sooner than it should on one side. I'll try the test program & report results shortly Marc
  7. M

    Stereo guitar/bass cabinet emulation

    One major problem I see with the WM8731 is high DC offset that seems to originate from the internal gain stage. This directly impacts the ADC dynamic range to an unusable level, as the signal will clip on the affected side no matter how the HPF is configured. I have 3 of these chips, and the...
  8. M

    Disabling program mode when using more than one Teensy?

    I remember accidentally causing the reverse of this - I could only program the lone Teensy by pushing the program button, even though USB was working fine I did this by changing the PRODUCT_ID value in usb_desc.h to a low value like 0x0001 Marc
  9. M

    Guitar Distortion Effect using waveshape and Teensy 4.0 with Audio Shield

    This would be a good start: Marc
  10. M

    Teensy 4.1 ADC Issue

    this sound like an input impedence issue; do you have any kind of buffer in front of the analog pins?
  11. M

    Joystick not recognised until Arduino IDE launched the Teensy port is selected

    I would start by commenting out lines 18&19 in file teensy_hotas.ino Marc
  12. M

    Choose pullup resistor ohms

    As mentioned previously, the DSE registers are used to control GPIO drive strength; this is typically used to curb EMI issues associated with fast signal transitions. Lowering the drive strength is roughly equivalent to having a series resistor between the GPIO pin & connected load. Pull-up/pull...
  13. M

    Understanding I2S for simultaneous read/write in AudioControlSGTL5000

    Also, the SGTL5000 is only one of many codecs with an I2S interface - there are many out there, ranging from inexpensive to co$tly. Thanks to a wide array of sound-enabled consumer products, most are either directly compatible, or require very little to be compatible with the Teensy audio...
  14. M

    USB isolator solution for Teensy 4.0 (vs T3.6)

    I ran into a similar issue with USB to RJ45 extenders, here's what I found: T3.x are USB Full Speed devices (12Mbps), whereas T4.x are High Speed by default (480Mbps) - those rates are bitstream rates, i.e. even if the usage data rate is low, the line encoding will always result in the specified...
  15. M

    T3 MIDI Out resistor calculations

    Is the upper resistor (pin 4) tied to 3.3v? It seems connected to ground in your schematic
  16. M

    HX711 and Teensy 4.1

    I've used this library successfully with many Teensies, including LCs, T3.2, T4.0 & T4.1 Is this the same library you are using with the Arduino? Marc
  17. M

    Help understanding mixer gain()

    That's the beauty of using the floating point (OpenAudio) library: you carry around ~24bits at each step; also, you can amplify & sum in mixers without worrying about clipping Marc
  18. M

    Trouble with SCL2 and SDA2 IC2 with 4.1

    According to the header file: bool begin_I2C(uint8_t addr = BMP3XX_DEFAULT_ADDRESS, TwoWire *theWire = &Wire); I would try this: bmp.begin_I2C(BMP3XX_DEFAULT_ADDRESS, &Wire2);
  19. M

    X100 inspired Guitar Processor

    Thanks Holger, I did not realize there was a separate repo for the delay - I will update the reference when came time to implement the chorus effect, I remebered playing with it on Microdexed. As I was doing it, I was thinking that it couldn’t be that simple; it actually was - great work you...
  20. M

    X100 inspired Guitar Processor

    Here's the signal flow from the Audio Design tool:
  21. M

    X100 inspired Guitar Processor

    Here's a project I finally managed to get working: It's a Rockman X100 emulator - 4 presets (Dist, Edge, Cln1, Cln2), Chorus & "Echo" (I used Freeverb - I tried emulating the original BBD echo, but it sounded like crap) The EQs are not 100% 1:1 with the original -...
  22. M

    need advises for designing low noise circuits

    I was just about to suggest ESP as well - lots of examples with good explanations, which helps in determining what are the critical design considerations (power supply, type of capacitors to use, etc.) Sadly this kind of knowledge seems to be going away with most of the audio processing now done...
  23. M

    Can Teensy work as USB host, connect directly to synthesizer's USB in (Type B) port? I've been using this for quite some time with the Teesy 3.6, and more recently with the 4.0 with great success Marc
  24. M

    Read Endless Potentiometer

    a good place to start would be with something like float angle = atan2f(val5, val6);
  25. M

    [posted] TeensyLev - an acoustic levitator (adapted from Asier Marzo's Tinylev)

    Really impressive! Bonus point for using wood PLA, first time I hear about this. Très bien fait en plus! Would you mind sharing the Teensy code? Marc
  26. M

    Well duh, the Teensy 3.6 is NOT 5v tolerant

    I think it would make more sense for Paul & the PJRC staff to focus their limited development resources into the core products, the Teensies (is it ok to pluralize them?) Given the relatively open nature of their products, nothing prevents a willing 3rd party to create & sell such a protection...
  27. M

    16bit gamma correction on Teensy not working as expected

    I just had to check for myself - indeed PROGMEM doesn't do anything on the Teensy: #define PROGMEM, and pgm_read_byte() is simply doing a reference cast to make it compatible with Arduino: #define pgm_read_byte(addr) (*(const unsigned char *)(addr)) Declaring strings & arrays with PROGMEM is...
  28. M

    16bit gamma correction on Teensy not working as expected

    In the Adafruit article, they are using a PROGMEM array (const uint8_t PROGMEM gamma8[] = {...), therefore it must be referenced as such: strip.setPixelColor(pixelNumber, pgm_read_byte(&gamma8[red]), pgm_read_byte(&gamma8[green]), pgm_read_byte(&gamma8[blue])); However, with the Teensy...
  29. M

    Help with joystick

    Alright, I understand - I'm willing to help, but I would like to understand your goal with this project. The way I see it, you could have bought a commercial Retropie bundle, ready (or almost ready) to play. Instead you got yourself a Teensy, which tells me you are curious about how this works...
  30. M

    Help with joystick

    There are a couple of issues here, but your main problem is probably caused by bad centering of the X/Y analog axis - you need to ensure that the values are as close to 512 when the joystick is centered for control assignment to work properly in Retropie Here are a few more suggestions: -You...
  31. M

    Help on connecting an I2C MPRLS pressure sensor from Adafruit

    Did you try invoking begin() with Wire2? Here's an example, taken from the Adafruit Github repo, modified to use pins 3&4 (Wire2) on a T3.6: #include <Wire.h> #include "Adafruit_MPRLS.h" // You dont *need* a reset and EOC pin for most uses, so we set to -1 and don't connect #define RESET_PIN...
  32. M

    Multiple I2c Teensy 3.5

    If I understand correctly, you want read sensors connected to pins 37 (SCL1) & 38 (SDA1)? All you need to do is replace instances of "Wire" with "Wire1": (sample code shamelessly stolen from examples) #include <Wire.h> void setup() { Wire1.begin(); } byte val = 0; void loop() {...
  33. M

    Good way to make a teensy based electric piano

    Thanks Holger! Building a MicroDexed is on my project list for this year. I will definitely pull sources from the Codeberg repo from now on. The work you did on porting these projects to the Teensy is very inspiring, and a great tribute to the capabilities of the T3.6 Marc
  34. M

    Good way to make a teensy based electric piano
  35. M

    send int-var with Serial1.write()

    The correct way to do this is: int i = 2; Serial1.print("myVar:"); Serial1.print(i); Serial1.print(";"); Marc
  36. M

    LM4040 external reference with Teensy 3.2

    I dug this out of a project that uses a single pot for menu navigation. Since this is on a Teensy LC there's no separate AGND, and the hot side of the 20k pot is connected to 3v3. It's pretty immune from supply noises, no cap needed in my use case. If I needed more that a few pots I would turn...
  37. M

    Phase shift measurement with Tennsy 3.6

    Since this looks like a typical signed/unsigned overflow issue, I would recommend these two changes: -Make Desphasage an unsigned int like the other variables: static uint32_t Dephasage; -Reverse the substraction: Dephasage = captureMes - captureRef; Marc
  38. M

    Headphone Jack Question for Audio Build.

    According to the SGTL5000 datasheet, output impedance is ~320ohm, therefore I don't think the chip would be damaged. You could always add a resistor between the line outs & the jack, but if I were you I would add a dedicated headphone jack (line out is really not that loud with headphones) Make...
  39. M

    LM4040 external reference with Teensy 3.2

    I would recommend you stick to 3v3 instead of using an external reference; normally, the ripple should affect both the ADC inputs and VREF at the same time, cancelling each other nicely (in theory!) With a few tricks you can pull this off almost entirely in software: -The ADC library allows you...
  40. M

    noob question about analog input with high resistance

    Another way to mitigate issues with large input impedance is to read the same pin multiple times to a dummy variable, while keeping only the last value. This allows the s&h cap to charge up properly. How many times depends largely on the ratio between the actual and optimal input impedance; for...
  41. M

    Anti Alias filters on SGTL5000

    If you have access to a suitable signal generator, you can test the performance (or presence) of the aa filter by injecting a signal above the nyquist freq. The signal will appear as a folded image reflected at the nyqyist point, i.e. 32khz signal should show up as a 10khz spike, along with some...
  42. M

    Teensy Loader problems

    I noticed this problem too (newly updated Win10, LC, 3.2 & 3.5). Running teensy_reboot.exe manually seems to work ok - it reboots & reprogram the teensy with the latest build. I use another Win7 computer that doesn't have this issue, which seems to confirm that this issue is cause by the recent...
  43. M

    High-Frequency High-Accuracy Photodiode with Teensy 3.2?

    Are you connecting the BPW34 directly to an analog pin? Unless you go with the S-6468 (which is a 5v device, btw), you would need a buffer op-amp with a very high input impedance (j-fet such as a TL072 or better). Use a clean supply for the op-amp - the onboard 3.3v supply may do with proper...
  44. M

    Line In Audio on Teensy Audio Adapter

    Yes line level audio should be fine, that's what it's designed for. I had ground loop issues when feeding from a different laptop (not the one connected via USB) - a cheap line level isolator fixed that Marc
  45. M

    Teensy 3.2 : Error opening serial port 'COMx' (Port busy).

    Could be related to this: http:// Marc
  46. M


    I have just uploaded my dynamics object here It's a combination of gate/compressor/limiter that I modeled after a popular unit I'm certainly not done optimizing it, it doesn't work on the LC (yet) but that should be a good starting point Marc