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  1. N

    DAC recommendations for Digital Oscillator project.

    > The MCP4822 is only dual but Edges has 5 audio outs, so how is it doing this? Out 4, which can be a triangle wave, uses the DAC; outs 1 to 3 are digital pulses so don't need a DAC. Out 5 is simply the analog mixture of the other four.
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    Teensy Web Page

    Yes, http://forum.pjrc.com/forum.php used to be correct but needs to be edited to http://forum.pjrc.com/ (or http://forum.pjrc.com/index.php )
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    Teensyduino 1.59 Released

    Okay nevermind. I did "copy link" from the link in the announcement post, and that actually is https://www.pjrc.com/teensy/td_156/package_teensy_index.json which is different to the text of the link
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    Teensyduino 1.59 Released

    I'm getting an update failure in Arduino IDE 2.3.0
  5. N

    freq measure multi on teensy 4.0

    From Github: Does that mean that each pin used for FreqMeasureMulti needs to use a different FlexPWM timer? Or just not share a timer with a different function, like PWM? I wasn't sure, reading the docs. (I have a project that needs two FreqMeasureMulti pins and six PWM outputs, so I was...
  6. N

    Full-range PWM for RGB LED control

    My current project needs two RGB LEDs as indicators. I'm using Adafruit Pirhana common-anode LEDs driven by PWM. https://www.adafruit.com/product/1451 I'm using at 146.48kHz to get 10 bit analogWrite resolution. I notice on a scope that the PWM duty cycles varies between 0.67% and 99.82% at...
  7. N

    Need advice on PCB manufacturers

    My first board was hugely wasteful of space, poorly routed, and I could do a lot better now. The important thing though was that I did it, and it worked, and I learned stuff. Autorouting tends to give poor results, KiCad makes manual routing simpler by guiding you. Running an electrical rules...
  8. N

    Miditransfer between USB-C port and Teensy

    Indeed, good point.
  9. N

    Did someone try a Teensy 4.1 MIDI with iOS?

    Are you sure that your iPad app is listening on channel 10?
  10. N

    Miditransfer between USB-C port and Teensy

    Why would it need a hub? This seems to just need a USB-C to USB-B cable, which is readily available, plus the USB host panel connector which has a USB-B socket.
  11. N

    T4.1 - USB Hosts – trouble getting started.

    You do need to use a standard 5-wire cable. The 5th wire is not just a shield; it is the 0V reference. Once you have done that, verify that =5V power is being supplied to the USB device. If not, you are likely missing the begin() command to enable power: USBHost myusb; void setup () {...
  12. N

    Teensy 4.0 DAC Function

    You would probably want to use an SPI DAC in that case. There are many options at various bit depths (from 12 to 18 bits) , both single and multi-channel. Most are surface-mount, but a few through-hole DAC chips still exist.
  13. N

    Question about MIDI modwheel & pitch bend control wiring

    No, because the Sustain pedal might be pressed (which delays acting on Note Off) and recently released keys may still be sounding due to the release phase of an ADSR envelope.
  14. N

    ornament & crime beta testing

    The bill of materials and build guide is online if you want to source yourself https://ornament-and-cri.me/build-it/ You could also try a kit, with all smd soldered already https://www.thonk.co.uk/shop/plum-audio-ocp/ If you plan on using the extra pins on a 4.1 then I would ask on the...
  15. N

    test thread

    UTF-8 test Το Teensy είναι μια εξαιρετική πλατφόρμα
  16. N

    Teensy 4.1 SPI SCK pin13 (LED) issue

    I have wondered whether an SD card extension cable like this could be butchered to bring out the SPI2 pins (SCK2, CS2, MOSI2, MISO2) without having to solder onto the QSPI memory pads. Anyone tried that?
  17. N

    Teensy 3.2 End Of Life

    This was a classic board, sad but understandable that is now at end of life.
  18. N

    MIDI 2.0 Support?

    MIDI 2.0 is still very new and there are zero commercial MIDI 2.0 controllers available. This thread may be helpful https://forum.pjrc.com/threads/55239-Midi-2-0?highlight=MIDI+2.0
  19. N

    MIDI 2.0 Support?

    MIDI 2.0 is still very new and there are zero commercial MIDI 2.0 controllers available. This thread may be helpful https://forum.pjrc.com/threads/55239-Midi-2-0?highlight=MIDI+2.0
  20. N

    How do I introduce real-time soft and hard clipping to an audio input?

    You might find these helpful: - Help with waveshaper effect - Adding harmonic distortion with Arduino Teensy - TeensyDist
  21. N

    16ch CV out project

    Oh and you should look at https://www.pjrc.com/better-spi-bus-design-in-3-steps/
  22. N

    16ch CV out project

    You would use a 5V supply (like V USB) to power the DAC and a level translator like 74AHCT125 to convert the 3V3 Teensy logic to 5V0. You would also need something like 4.7μF + 100nF supply bypass caps on AVdd. DAC8568C outputs up to 5V (2 * Vref) and has a zero-scale reset. Do you really need...
  23. N

    16ch CV out project

    For CV out you do need DC accuracy which means audio DACs are not a good choice. Have a look at something like the DAC8568 from Texas Instruments; it gives you eight reasonable quality 16-bit outputs (4LSB INL, 0.004% typical Initial Accuracy), has an internal voltage reference that is good...
  24. N

    Building a USB MIDI 2.0 Device

    Good to see the platforms (MacOS X, Linux, Android) building support, but there is still not a single MIDI 2.0 controller on the market (that includes the somewhat flawed Roland A-88Mk2 which maybe, maybe is hiding 16-bit velocity and 32-bit parameter support inside it's current, MIDI 1.0...
  25. N

    External ADC and DAC recommendations for T4.1

    By the way for people needing guidance on high precision DAC, this article from Analog.com on the 20-bit AD5791 is excellent, and broadly applicable to other DACs: The 20-Bit DAC Is the Easiest Part of a 1-ppm-Accurate Precision Voltage Source I'm (slowly, as ever) working on a project that...
  26. N

    External ADC and DAC recommendations for T4.1

    Audio components are optimized for audio applications (streaming data at a constant rate, low total harmonic distortion, etc). That particular codec especially (zero-crossing gain modification to eliminate clicks, high-gain microphone amp with microphone bias, etc). The datasheet may be entirely...
  27. N

    Using the SPI library for AD5686R DAC with Teensy 4.1

    Oh, I considered asking about that but forgot. The datasheet, section Layout Guidelines, says there should be 10μF plus 100nF at the power pins (digital and analog). Those would be a low-ESR electrolytic and a C0G ceramic, typically.
  28. N

    Using the SPI library for AD5686R DAC with Teensy 4.1

    SPI.transfer expects one byte (8 bits, uint8_t). To send a 16bit quantity you can send two bytes, MSB first. I don't have the particular DAC you are using but I looked at a couple of sketches using other DACS to see what I did: AD5542, and LT1658C. Try this: // Control AD5686R quad 16bit SPI...
  29. N

    Using the SPI library for AD5686R DAC with Teensy 4.1

    In terms of accuracy, it depends whether you got the A grade or the more expensive B grade. For A, the relative accuracy is ±2 LSB typical, ±8 LSB max. Assuming you have a gain stage that takes the 2V5 or 5V0 DAC output to 11V, then 1 LSB is 11 / 2^16 = 168μV = 0.2 cents (1200 cents to 1 volt)...
  30. N

    Using the SPI library for AD5686R DAC with Teensy 4.1

    Your setup does not work because you are sending command 0000 which is "No operation". You need 0001 which is "Write to input Register". So int setDacChannelLevel(int address, int value) { digitalWrite(slaveSelect, LOW); SPI.transfer(address + 16); SPI.transfer(value)...
  31. N

    MIDI all notes off

    Yes, it does. This has the feel of "great new idea, nice in theory", spoiled by backwards compatibility and divergent implementations in practice. Also the "not in OMNI mode" caveat at least has some justification.
  32. N

    MIDI all notes off

    From the MIDI 1.0 spec (my emphasis): So it is efficient if implemented but the safe and secure method, assuming you have a list of notes turned on, is (sadly) sending all the corresponding Note-Off messages. The specification wording is classic post-hoc standardization:
  33. N

    SPI Bus only first declared chip select board reads properly.

    The voltage divider on MISO is a test, not a solution. What voltage did you measure? If your SPI slave devices do not tristate correctly, you will need to add a tristate buffer such as SN74AHCT125. You can then drive the output enable pins to allow data to flow to the selected slave SPI device.
  34. N

    Mixed voltage sources

    > I have a bunch of TL074 quad op-amps around, so I would use one of them since it works with 5V just as well. No, it doesn't. TL072 and TL074 do not work well a couple of volts away from the rails, which is fine with a ±10V swing on ±12V or ±15V rails; not so great with ±5V rails. In...
  35. N

    cannot get FreqMeasure Library to work on Teensy 4.0

    Do you have any input conditioning, filtering, squaring circuitry such as this or is the signal generator connected directly to the pin?
  36. N

    filter cut off frequency and keyboard tracking

    You are doing calculations in the linear, frequency domain: converting MIDI note to a frequency then adding a scaled offset. That will not work because perception of pitch is logarithmic, not linear. Instead convert your example filter resonant frequency (here 1000 Hz) into a MIDI note and then...
  37. N

    different MIDI Channels Out via USB or 5 Pin

    Deleting a post is not helpful to others. Posting what solution you found, on the other hand, is. I assume you found that Teensy has many serial outputs and thus, sending some messages on channel 1 to one DIN MIDI and others on channel 2 to a different DIN MIDI is fairly easy?
  38. N

    Transition

    You could have a look here: https://github.com/TeensyUser/doc/wiki/Pins Could you add a short, complete program which works on 3.6 but not on 4.x? (see forum rule).
  39. N

    Porting a project from 3.6 to 4.1: what should I look out for?

    Hi Paul! Yes, I planned to use the ordinary SPI library, with transactions.
  40. N

    Porting a project from 3.6 to 4.1: what should I look out for?

    I'm about to resurrect a project I started on 3 or 4 years ago and abandoned (health issues, other priorities) a couple of years ago. Meanwhile, supply-chain issues mean that the original target, Teensy 3.6, seems unavailable so I am changing to 4.1 (no ethernet needed). I'm aware of some pin...
  41. N

    TEENSY41_NE problem with i2c (wire2)

    From https://github.com/Richard-Gemmell/teensy4_i2c
  42. N

    USB MIDI : how to connect Teensy sequencer + Teensy synth + ext Keyboard ?

    Connect your sequencer and your keyboard to a USB hub (I would use a powered hub, if you have one) then connect your hub to the MIDI host port on your Teensy synth.
  43. N

    Will USB MIDI handle MPE ?

    Bit of a late response, sorry, but a bit more detail: Yes, you can implement MPE on top of Teensy USB MIDI 1.0 just like you can implement the rest of MIDI 1.0 on top of Teensy USB MIDI. MPE just adds extra meaning to a particular arrangement of channels - channel 1 is the master channel which...
  44. N

    Planned Forum Migration

    Having seen many suboptimal forum migrations, I have one request. Please find out ahead of time what character encoding is currently in use (hopefully, UTF-8) and what character encodings are supported for import on the new platform (also, hopefully UTF-8) so that non-ASCII characters are...
  45. N

    Using Faust with Teensy

    Hmm, I'm getting an error with a fresh install of Arduino 1.8.12 and Teensyduino 1.5.1. I added the two faust-specific lines near the top of platform.txt: # http://www.pjrc.com/teensy/teensyduino.html name=Teensyduino version=1.8.5 rewriting=disabled ## Special Faust/Audio Compilation Flags...
  46. N

    Schematic reading help MIDI IN DIN

    (CA-033) MIDI 1.0 Electrical Specification Update [2014], available on MIDI.org (free, requires registration for download) has a lot more detail than the original and very sketchy MIDI 1.0 electrical "specification". In particular it adds details for changes to the MIDI out low voltage...
  47. N

    Web App to interact with a USB-Connected Teensy

    Yes, correct. This is not mandated by the Web MIDI specification but is something that Chrome changed in mid-2019, and Firefox will also require when their implementation ships (actually the Firefox implementation may ship at first with SYSEX disabled completely. This is originally motivated by...
  48. N

    What applications truly need both Teensy 3.5 / 3.6 built in DACs?

    I have never used both built-in DACs on 3.5/3.6. I have used the single DAC on LC or 3.2 to generate control voltages (CV) for analog modular synthesizers (Eurorack); unlike Theremingenieur I only used these for non-pitch CV (random walk generators, envelope generators for controlling VCAs and...
  49. N

    Book Recommendations for Audio Programming

    Perry Cook's book is clear and good. I have it. The older edition came with a CD-ROM but secondhand copies may lack this. The newer edition puts this material online, but the printed URL for supporting materials is out of date. Go to: https://www.cs.princeton.edu/~prc/AKPetersSoundExamples/...
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