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Thread: Teensey 4.0 i2c burning

  1. #1
    Junior Member
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    Teensey 4.0 i2c burning

    hey,
    i tried comunicating with two teensey 4.0 , making one master reader and one slave sender, using the simple wire library example.
    i conneted them using an electric board i made, and for some reason one of them burned out.
    i attached a photo with the connection i did , and the wire example code.
    would appreciate any advice or something to look for as i am clueless of what could be the problem.

    thanks in advance

    master:
    Click image for larger version. 

Name:	צילום מסך 2022-05-18 160515.jpeg 
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    slave:
    Click image for larger version. 

Name:	צילום מסך 2022-05-18 160542.jpeg 
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    wire diagram:
    Click image for larger version. 

Name:	צילום מסך 2022-05-18 160244.jpeg 
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ID:	28410

  2. #2
    Senior Member+ KurtE's Avatar
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    Might help to know additional information like: Burned out - Are you saying, that the board had some magic smoke, or just stopped working or...

    Power connection from PC. Are we saying USB power with voltage about 5v?

    If so looks like you are feeding it to the encoders? Are any of the IO pins connected up to the encoder like GPIO pins 3, 7, 8 being fed voltages > 3.3v? Again the Teensy pins are not 5v tolerant.

  3. #3
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    usb power voltage 5v indeed, by burned out i mean stopped working( even simple blink code), and yes we are feeding it to encoders to read their data, and they are fed 3.3 . the thing is that when i tried reading from the encoders using one board everything worked just fine, the problem was when i tried using both of them.

  4. #4
    Senior Member
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    The etch shows 5 volts going directly to pin 3, does it not? It doesn't even matter if the encoders were not plugged in, pin 3 will still see 5 volts.

  5. #5
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    i see what you are saying, it is just confusing in the diagram tho, pin 3 hav 3.3V and there is no connection there to the 5V as it seems in the picture. i checked it with a voltage-meter.

  6. #6
    Senior Member
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    I don't see how it can not be connected unless that etch run has burnt open. You could check that by checking for 5 volts over on pin 1 of Encoder1. (But it would be much better if you check for etch continuity using an ohm meter rather than volt meter.) I think you can salvage the boards you have made by just pulling pin 3 out of the Teensy's.

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