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Thread: 3.1 Breakout Board and Extra Pins

  1. #1

    3.1 Breakout Board and Extra Pins

    Hi,

    This is proably very basic for someone? Im using my teensy 3.1 with a Breakout board to access all pins!
    Ive checked continuity and everything is OK!? But if i use Arduino ide to say turn on and off A10 for 2000ms delay it dosen't work?

    If i use any of the pins that are normaly connected to the standard pins of 3.1 it works?

    Is another Bootloader or something needed to access all pins?

    Kind regards Baggey

  2. #2
    Senior Member+ MichaelMeissner's Avatar
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    There are several pins that can be used only for analogRead calls on the 3.1/3.2 (one pin can also be used for analogWrite). These are pins that the card does not list a decimal number for. In addition, these pins are not protected against 5v, so you must keep the input to under 3.3v:

    On the Teensy 3.1/3.2, the following pins are not available for digitalRead or digitalWrite:
    • Pins A10 and A11 that on on the inside as through hole pins;
    • Pins A12 and A13 that are solder pads underneath the Teensy;
    • Pin A14, which is a through hole pin on the back (this pin is the digital->analog converter that can be used with analogWrite -- it alters the voltage, rather than turning the pin on/off like the other PWM pins do to simulate a lower voltage).

  3. #3

    Cool

    Okay then ill try pin 28 or A17:


    int pin = A17;
    void setup()

    {



    pinMode(pin, OUTPUT); // sets the pin as output

    }

    void loop()

    {
    digitalWrite(pin, HIGH);
    delay(2000);
    digitalWrite(pin, LOW);
    delay(2000);


    }


    This is the code im using still dosen't work?
    Im sure or i hope your going to point out the obvious?

  4. #4
    Junior Member
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    Oct 2016
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    Quote Originally Posted by Baggey View Post
    Okay then ill try pin 28 or A17:


    int pin = A17;
    void setup()

    {



    pinMode(pin, OUTPUT); // sets the pin as output

    }

    void loop()

    {
    digitalWrite(pin, HIGH);
    delay(2000);
    digitalWrite(pin, LOW);
    delay(2000);


    }


    This is the code im using still dosen't work?
    Im sure or i hope your going to point out the obvious?
    Why not using 28? A17 is for analog, 28 for digital

  5. #5
    Senior Member+ KurtE's Avatar
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    Looks like it should work. Assuming that it compiles. That is the line Okay then ill .... won't compile is not a comment line...

    How do you know it is not working? If you verify that it compiles and downloads, then is should work...

    One way I experiment is to use pin 13's LED to help me test... That is I do something like:
    Code:
    nt pin = A17;
    void setup()
    
    {
        pinMode(pin, OUTPUT); // sets the pin as output
        pinMode(13, INPUT); // use it to see state of other pins...
    }
    
    void loop()
    
    {
      digitalWrite(pin, HIGH);
      delay(2000);
      digitalWrite(pin, LOW);
      delay(2000);
    }
    Then run a jumper from your pin A17 to pin 13 and the LED should reflect the current state of pin A17...

  6. #6
    Quote Originally Posted by KurtE View Post
    Looks like it should work. Assuming that it compiles. That is the line Okay then ill .... won't compile is not a comment line...

    How do you know it is not working? If you verify that it compiles and downloads, then is should work...

    One way I experiment is to use pin 13's LED to help me test... That is I do something like:
    Code:
    nt pin = A17;
    void setup()
    
    {
        pinMode(pin, OUTPUT); // sets the pin as output
        pinMode(13, INPUT); // use it to see state of other pins...
    }
    
    void loop()
    
    {
      digitalWrite(pin, HIGH);
      delay(2000);
      digitalWrite(pin, LOW);
      delay(2000);
    }
    Then run a jumper from your pin A17 to pin 13 and the LED should reflect the current state of pin A17...
    OKay. Been testing some more this morning.
    All pins are working now. I had a dry solder joint on pin 28 or A17.

    The outputs are only giving me 3.3V i need 5V?

    So technically we have only 33 Digital pins on the 3.2 with a breakout board as A10 - A14 are not usable for digital?

  7. #7
    Senior Member+ Frank B's Avatar
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    Baggey, the teensy works with 3.3Volt. It can not output 5V. You need additional HW if you need 5V.

  8. #8
    My first thought is using transistors switching 5v with a current limiting resistor. Am i in the write area or is there another IC i can use.

    I want to read an old ZX81 D2364C and create a dump of it. I know the ROM is available for down load but theres no fun in that.

    Kind regards Baggey

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