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Thread: Adc info

  1. #1

    Adc info

    Hi everyone,
    Isn't one thing clear to me, all analog pins support 5V?
    Thank you

  2. #2
    Help please!!!

  3. #3
    Senior Member+ defragster's Avatar
    Join Date
    Feb 2015
    Generally No, Depends on what Teensy you are talking about. If Teensy #??? came with a card it will have some notes about 5V tolerance being prohibited on: all T_LC, T_3.6 pins and even T_3.5 analog only pins.

  4. #4
    Senior Member+ MichaelMeissner's Avatar
    Join Date
    Nov 2012
    Ayer Massachussetts
    And in addition to what defragster says, even on the Teensy 3.2/3.5 which does support 5v tolerance on the digital pins, any voltage above 3.3v (or the analog reference voltage if you use that) will be read as the maximum value. So for instance, if you have a Teensy 3.2, and you do an analogRead on pin A0, if the voltage is 3.3v it will read 1023. If the voltage is 5v, it will still read 1023.

  5. #5
    teensy use 3.2, what is important is that I can give 5v to the adc without burning.
    I do not use A10-11-12-13-14, but all others.

  6. #6
    Senior Member PaulStoffregen's Avatar
    Join Date
    Nov 2012
    Yes, all the other pins (the ones which also have digital I/O capability) are 5V tolerant, on Teensy 3.2 and Teensy 3.5.

    So you can indeed drive them with a signal that goes up to 5V without damage to the hardware.

    However, all voltages between 3.3V to 5V will read as the maximum value, which is 1023 with the default 10 bit resolution setting.

    Teensy LC, Teensy 3.6, and future Teensy models are NOT 5 volt tolerant. This only applies to Teensy 3.2 and Teensy 3.5.

  7. #7
    Hi, to read adc do you recommend the library or a normal analogread?

  8. #8
    Senior Member PaulStoffregen's Avatar
    Join Date
    Nov 2012
    If analogRead() meets your needs, use it. Simpler is better.

    If you need more advanced features, look into the ADC library. But it comes with quite a cost of complexity. Try the simple way first!

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