WiPy 2.0 and DHT22


  • Pybytes Beta

    Hi folks,

    i have to connect a DHT22 to the WiPy 2.0.
    The WiPy is mounted on the Expansion Board v2.1A.

    I'm no hardware guy, just software.
    So i need help with the wiring of the sensor to the board. VDD and GND are a no-brainer,
    but which pin shall i use for the DATA signal?
    And which settings are required for the pin?

    I have seen that in some sketches a pullup resistor of 10k is used between VDD and DATA.
    Is this as well necessary for the WiPy 2.0?

    In addition: Has anybody already a working driver for the sensor?
    I know that there is some code for the pyboard but my latest news is that this does not
    work on the WiPy.
    With some help from a hardware guy i can support a port of the DHT11/22 module.

    Many thanks in advance,
    Marc



  • @Ralph
    especially this not exists in WiPy
    from pyb import ExtInt

    and

    ExtInt(data, ExtInt.IRQ_FALLING, Pin.PULL_UP, None)
    ExtInt(data, ExtInt.IRQ_FALLING, Pin.PULL_UP, edge)
    

    It is good startup but someone must have knowledge how to port.
    Maybe i will port this (or meybe someone done it already?) - i have DHT11(less accurate but the principle is the same)
    but i wait for new firmware and timers support


  • Pybytes Beta

    Hi Ralph,

    thanks for your fast answer.

    I already found the library you mentioned. But it is written for the pyboard and not for the WiPy.
    There i am in the need for help on the hardware side...

    For the pins i am no step further. Hardware is a sealed book for me, i have absolutely no knowledge
    and can't read schematics well. That why i asked for an explicit pin to use.
    I develop software for my living but the hardware side is not developed at all at the basic level.

    But thanks anyway,
    Marc



  • Hi,

    I don't have this sensor, but it seems like there is a micropython lib available here.

    For info about the pins, check the pinouts in the documentation. I think in this case you need to use pins without a pullup resistor. Also look at the expansionboard pinout over at the docs, and check which pins are in use for things like the button and led on the board.

    Does that get you any further?

    Regards, Ralph


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