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Thread: Teensy 4.1 with 5V levels

  1. #1

    Teensy 4.1 with 5V levels

    Hi,

    I regularly reach the limits of the Arduino Mega Pro Mini, particularly in terms of RAM usage, so I look to a more powerful board (I don't need more power but mainly more RAM...).

    While the Teensy 3.5 is said as "5V tolerant" on this page: https://www.pjrc.com/teensy/
    the Teensy 4.1 said nothing about this...

    My peripherals are mainly 5V, so...

    Is it 5V tolerant ? and if not, how to you proceed to properly undertake 5V inputs and outputs ? do you use a 5V<->3.3V converter ?

    Thanks

    P.S.: the Teensy 3.5 would be fine for my usage but seems a bit difficult to find in Europe and its price is almost the same than the 4.1
    Last edited by nounours18200; 01-10-2022 at 04:53 PM.

  2. #2
    Senior Member+ defragster's Avatar
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    On this page it is made clear the Teensy 4.1 is 3.3V MAX : pjrc.com/store/teensy41.html
    > the same applies to T_3.6 and T_4.0

    It is printed on the card that is to come with every Teensy 4.1: pjrc.com/teensy/card11b_rev4_web.pdf

    Code:
    Digital Input Pins
    Digital pins may be used to receive signals. Teensy 4.1 pins default to INPUT most with a "keeper" resistor. Teensy 4.1 pins accept 0 to 3.3V signals. The pins are not 5V tolerant. Do not drive any digital pin higher than 3.3V.
    
    Analog Range
    The analog input range is fixed at 0 to 3.3V. On Teensy 4.1, the analogReference() function has no effect. The analog pins are not 5V tolerant. Do not drive any analog pin higher than 3.3 volts.
    Others may offer details on the 5V <> 3.3V conversion, but it will depend on the source and type of the device or input at hand so more details would be called for.

    Bummer the T_3.5 isn't easy and cost effective to get as it would likely solve the issues directly - and in the end might be more cost effective and cleaner solution.

  3. #3
    On this page it is made clear the Teensy 4.1 is 3.3V MAX
    agreed, I had seen that meantime, sorry for asking a so evident question...

    Others may offer details on the 5V <> 3.3V conversion, but it will depend on the source and type of the device or input at hand so more details would be called for.
    I understand, I will give more detail, probably in another thread

    Bummer the T_3.5 isn't easy and cost effective to get as it would likely solve the issues directly - and in the end might be more cost effective and cleaner solution.
    I am not sure to perfectly understand what you mean, but I also study the T-3.5 because it looks like a much simpler solution to my projects: I do not need the CPU power of the T-4.1....

  4. #4
    Senior Member+ defragster's Avatar
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    Quote Originally Posted by nounours18200 View Post
    ...
    I am not sure to perfectly understand what you mean, but I also study the T-3.5 because it looks like a much simpler solution to my projects: I do not need the CPU power of the T-4.1....
    That was in response to this note:
    P.S.: the Teensy 3.5 would be fine for my usage but seems a bit difficult to find in Europe and its price is almost the same than the 4.1
    It should safely work as needed withtou extra work that may save in the long run. If doing Analog readings from a 5V max that would be an issue. And while typically 3.3V is enough for 5V devices to recognize that as HIGH - it might not be the case with all devices.

  5. #5
    Senior Member BriComp's Avatar
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    P.S.: the Teensy 3.5 would be fine for my usage but seems a bit difficult to find in Europe and its price is almost the same than the 4.1
    I had no difficulty finding stock in Europe. The following have stock coolcomponents,Thepihut,Pimoroni

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  7. #7
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    Added those to the user wiki here: https://github.com/TeensyUser/doc/wiki/Vendors

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    Note, exp-tech is B2B only.

  9. #9
    Junior Member TomChiron's Avatar
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    Antratek is another one:

    https://www.antratek.com/boards/teensy

  10. #10
    Thank you very much to all of you !

  11. #11
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    Quote Originally Posted by nounours18200 View Post

    My peripherals are mainly 5V, so...
    ...it's time to update to more modern peripherals. You'll notice that they are better, too.

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