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  1. Oops, sorry you are correct, as far as I know the...

    Oops, sorry you are correct, as far as I know the ADC lib has not yet been ported to T4.
  2. Very cool! Microcontrollers are not what they...

    Very cool! Microcontrollers are not what they used to be.
  3. I assume the same code would work on T4 but...

    I assume the same code would work on T4 but remember there are a few differences. The T4 does not have an external Vref input (the internal 3.3V is the only option) and also it uses a 12-bit ADC (but...
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    Here is my code (modified library + sample...

    Here is my code (modified library + sample dual-ADC application) which has now run 8 hours sampling two ADC chips, each one at 500 Hz, without any obvious error: ...
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    Just in case of interest, I did modify the...

    Just in case of interest, I did modify the Flydroid library to allow using two different ADS1256 devices on one Teensy. It "usually" works, not yet 100% confident it always does.

    Separate from...
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    You are thinking of them as numbers, but I'll bet...

    You are thinking of them as numbers, but I'll bet something on the OS side is thinking of them as ASCII control characters.
    Decimal 17 and 19 are DC1 and DC3, aka Control-Q and Control-S, often...
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    It appears that this library...

    It appears that this library https://github.com/Flydroid/ADS12xx-Library may allow for more than one ADC instance, each with separate control pins, so I'll try that.
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    I'm using the ADS1256 code from Matt Bilsky at...

    I'm using the ADS1256 code from Matt Bilsky at https://github.com/mbilsky/TeensyADS1256 on a Teensy 4 and it is working well at the moment. In the past I used a different hardware setup, using T3.2...
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    The most convincing way to decide would be if...

    The most convincing way to decide would be if there was an industry-accepted "class compliance test suite" that could test a device or host for every officially defined feature, and say yes or no. I...
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    In the past I used JeeNode...

    In the past I used JeeNode and Moteino devices, for very low power, low baud rate communications. They worked pretty well, although not as standard (or power-hungry) as BT or wifi.
    For very...
  11. During the first T4 Beta round (1052 device), I...

    During the first T4 Beta round (1052 device), I noted that the "keeper" mode on the ADC input pins was set by the default initialization, which reduces idle power consumption, but also causes a small...
  12. Thanks for that correction defragster, I did...

    Thanks for that correction defragster, I did misinterpret the problem. I would correct or delete my earlier post but the forum no longer seems to allow that.
  13. Your setup code includes:...

    Your setup code includes: "Serial.println("Starting ...");" which uses the Teensy USB-serial device. Currently on T4 I believe if you send any characters to the USB-Serial device (using Serial.X...
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    Thanks for this update. From your experience,...

    Thanks for this update. From your experience, some of my mine, and this post https://forum.pjrc.com/threads/57415-Teensy-4-0-Speeduino-compile-fail?p=214119&viewfull=1#post214119 among others, I...
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    Even though in theory the Teensy can still work...

    Even though in theory the Teensy can still work with it, 4.17 V is not at all within the USB spec, so I would say that is a poor quality cable. 4.79 V with no cable is also a bit lower than I expect...
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    The original code not compiling seems like a clue...

    The original code not compiling seems like a clue that the code running on the OP's T4 is not what is listed; possibly it is still the original blink sketch?
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    Looking forward to your results; I am interested...

    Looking forward to your results; I am interested in doing the same thing.
  18. I haven't measured this but most digital chips of...

    I haven't measured this but most digital chips of any kind have ESD protection diodes to clamp the pins to the power rail. So a brief pulse above Vcc gets clamped to Vcc + 1 diode drop, for example...
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    I don't know enough to say but just as a guess,...

    I don't know enough to say but just as a guess, if this is full-duplex, eg sending 7 bits and receiving 7 bits at the same time, I suspect the FPGA is a safer bet at this point. Maybe even if it's...
  20. Thread: Teensy 4 dead

    by JBeale
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    The Adafruit display used 10k pullups to +5V. If...

    The Adafruit display used 10k pullups to +5V. If you connected that display to a chip clamping inputs to +3.3 V + some diode drop, you might only have around 0.1 mA flowing into the pin. I'm not sure...
  21. The linked datasheet does not say what the output...

    The linked datasheet does not say what the output voltage is. At any rate you must not exceed the voltage tolerance of the specific pins you are using on your Teensy 3.2.

    "All digital pins are 5...
  22. The manufacturer's datasheet and programming...

    The manufacturer's datasheet and programming manuals for the various chips used in the different Teensy versions are here:
    https://www.pjrc.com/teensy/datasheets.html

    There is a lot of detail and...
  23. I gather you want to use someone else's...

    I gather you want to use someone else's libraries, not Teensy/Arduino. The main selling point of the Teensy boards is (for me) that they're easy to use because of Arduino-style libraries. The PJRC...
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    I suspect it's possible to kill a single pin with...

    I suspect it's possible to kill a single pin with the rest of the chip still OK, by destroying that pin's output buffer, for example by a large enough ESD hit.

    EDIT: You can also get the same...
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    Isn't it possible to use any GPIO pin as a chip...

    Isn't it possible to use any GPIO pin as a chip select? That's assuming you bit-bang it with separate code, which is slower, but if you are sharing the bus presumably you don't need the 2nd-Nth...
  26. PJRC indicates the T3.2 board is in stock for...

    PJRC indicates the T3.2 board is in stock for now: https://www.pjrc.com/store/teensy32.html and the CPU it uses is in stock at the large distributors. I would expect Paul to have many months, if not...
  27. Thread: Teensy 4 dead

    by JBeale
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    Without implying anything about your setup which...

    Without implying anything about your setup which I know nothing of, I notice the Adafruit version of their ILI9341-based touchscreen...
  28. I think the quick answer is, you can do anything...

    I think the quick answer is, you can do anything the hardware can do. There are a few choices: you can use any of various existing Arduino type libraries, which make interfacing pretty easy, or you...
  29. There are many different clocks used on the...

    There are many different clocks used on the Teensy. Yes it has a 600 MHz instruction clock internally, but for interfacing with the outside world, input signals have to be synchronized to prevent...
  30. Thanks for the reply Paul. Indeed it was the...

    Thanks for the reply Paul. Indeed it was the age-old problem that somehow I had not seen before on this machine. I did have /etc/udev/rules.d/49-teensy.rules in place but that wasn't good enough....
  31. My workaround for now is to just use a real...

    My workaround for now is to just use a real serial UART instead of serial-over-USB. The Teensy's real UART serial communication works fine.
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    In a word, yes. I'm seeing even worse serial...

    In a word, yes. I'm seeing even worse serial issues than you, I have USB-Serial dropouts even sending as slow as 30 characters per second (!) but there must be something wrong with my system as it's...
  33. "...when it hears the request from Arduino....

    "...when it hears the request from Arduino. Without the chip present, that code will crash, if it is ever run."

    I read this to mean: IF you leave the code in, and IF an Arduino host on USB...
  34. I also have Arduino 1.8.8 / Teensyduino...

    I also have Arduino 1.8.8 / Teensyduino 1.46-beta9 installed on the Linux Mint box, and the same problem appears there as well.
  35. Arduino 1.8.9 + Teensy 1.47 : T3.2 USB Serial monitor drops lines?

    My host PC is a "fitlet2" Linux Mint MiniPC, and 'uname -a' says
    4.15.0-55-generic #60-Ubuntu SMP Tue Jul 2 18:22:20 UTC 2019 x86_64 x86_64 x86_64 GNU/Linux

    I am running Arduino 1.8.9 +...
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    Does the radio also use SPI? Is there any chance...

    Does the radio also use SPI? Is there any chance of a SPI bus conflict between the custom radio receiver unit and the SD card?
    EDIT: nevermind, assuming you are using the built-in SD card socket on...
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    Yes, I used tempmonGetTemp() to produce this...

    Yes, I used tempmonGetTemp() to produce this graph from which I estimated my T4's 24MHz osc tempco at -0.24 ppm/C near room temp. My board's tempco also rolls off to near zero when the ambient was...
  38. If you're using any external entropy source, like...

    If you're using any external entropy source, like a diode, might also want some kind of statistical check to make sure it didn't accidentally or on purpose get stuck on all 0's or 1's.
  39. One of the companies I worked for made a consumer...

    One of the companies I worked for made a consumer product involving crytographic authentication, using a dedicated chip doing a secure exchange between the device and a consumable pay-as-you-go token...
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    With a few slight changes to TelephoneBill's...

    With a few slight changes to TelephoneBill's code, I have a precision pulse generator with an adjustable period. I can tweak it with 'u' or 'd' serial commands (a manual-feedback PLL) to keep the...
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    thank you TelephoneBill!

    Outstandingly useful, thank you very much! With your code, merely by substituting in a timer constant of (74999999-611) I was able to achieve a 1 PPS output on my particular T4 that stayed within 4...
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    @TelephoneBill - thank you very much, I see...

    @TelephoneBill - thank you very much, I see https://forum.pjrc.com/threads/54711-Teensy-4-0-First-Beta-Test?p=209786&viewfull=1#post209786 looks very encouraging. Is your 150 MHz clock testing code...
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    PWM, clocks, prescalers and timing resolution

    Thanks, I will search for it. When I do this:

    analogWriteFrequency(4, 20);
    analogWrite(4, 128);
    I get an output from pin 4 which is fairly close to 20 Hz, and it is stable over time, but it...
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    T4: jitter-free low frequency output pulse?

    I'm looking for an accurately-settable, low frequency, jitter-free output pulse from Teensy 4. The Frequency Timer 2 library allows setting the period in microseconds, but is not yet ported to T4....
  45. I don't know the general answer to your question...

    I don't know the general answer to your question but I do know on Teensy 4 the FreqMeasure input is pin 22, hopefully the FreqMeasure page gets updated soon given that each Teensy model is different.
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    In case of interest, here's a quick test of the...

    In case of interest, here's a quick test of the clock frequency vs. temperature on the newly released Teensy 4 model. Mine has a tempco around -0.24 ppm / C near room temperature, but it was...
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    frequency vs temperature

    With my office ambient temperature around 23 C, my T4 running a simple FreqMeasure test reports itself at T= 56 C after some time to equilibrate, and its clock runs 9 ppm slow relative to my 1-PPS...
  48. Sticky: Teensy 4: DMAMEM keyword needed to access other...

    Teensy 4: DMAMEM keyword needed to access other half of RAM, if 512 KB isn't enough:...
  49. "1024K RAM (512K is tightly coupled)" from...

    "1024K RAM (512K is tightly coupled)" from https://www.pjrc.com/store/teensy40.html
    Given apparently two different blocks of RAM which are connected to the CPU in different ways, are they also...
  50. Sticky: Teensy 4: FreqMeasure input is pin 22 (various...

    Teensy 4:
    FreqMeasure input is pin 22 (various Teensy models use various pins). https://www.pjrc.com/teensy/td_libs_FreqMeasure.html
    tempmonGetTemp() returns the internal CPU temperature for T4...
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