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Piface Digital - Relais

Former Member

Hallo zusammen,

 

erstmal zu meinem Setup:

- Raspberry Pi Mod. B

- Piface Digital 2.1

- Raspbian Wheezy 7.2

 

Ich habe dasProblem, wenn ich das erste relais (0) schließe, kann ich das zweite relais (1) nichtmehr ansteuern. Andersherum ist es aber kein Problem. Habe auch schon andere Pifaces getestet, allerdings das gleiche Problem. Hättet ihr da eine Idee?

 

Besten Dank im Voraus :-)

  • 0

    Can you please provide a wiring diagram and the code your using for this, I may then be able to help (Pictures too will help), also please refer to http://www.element14.com/community/community/raspberry-pi/blog/2014/03/07/raspberry-pi-usb-power-cables-crashing-and-other-problems?et=blogs.comment.created#comment-31786 as you may be experiencing a power issue depending on the quality of your supply to the PI. using Google translate for this response so please forgive it it is worded badly.

     

    Können Sie bitte ein Schaltbild und den Code Ihr mit für diese, kann ich dann in der Lage zu helfen (Fotos zu helfen), auch finden Sie unter http://www.element14.com/community/community/raspberry-pi/blog/2014/03/07/raspberry-pi-usb-power-cables-crashing-and-other-problems?et=blogs.comment.created#comment-31786 wie Sie vielleicht erleben eine Machtfrage abhängig von der Qualität der Versorgung des PI. übersetzt mit Google Trans für diese Antwort, so bitte vergib es ist schlecht formuliert.

  • 0 in reply to Robert Peter Oakes

    Hi Peter,

     

    thanks for your reply.

     

    The code looks like this:

    #Import piface library
import  pifacedigitalio

#create and initialise pfd object
pfd = pifacedigitalio.PiFaceDigital(init_board=False)

#Access relay
def access_gpio(pin, value):
         pfd.relays[pin].value = value

     

    And those are the installed packages

     

    ii  python-pifacecommon               4.0.0-1                            all      The PiFace common functions module.
    ii  python-pifacedigitalio            3.0.4-1                            all      The PiFace Digital I/O module.
    ii  python3-pifacecommon              4.0.0-1                            all      The PiFace common functions module.
    ii  python3-pifacedigital-emulator    2.0.2-1                            all      The PiFace Digital I/O emulator.
    ii  python3-pifacedigital-scratch-handler 2.0.5-1                            all      The PiFace Digital Scratch Handler.
    ii  python3-pifacedigitalio           3.0.4-1                            all      The PiFace Digital I/O module.

     

    Wiring:

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  • 0 in reply to Former Member

    I don't know too much about the piface digital, but from the code ( https://github.com/piface/pifacedigitalio/blob/master/pifacedigitalio/core.py ) looks like if you pass False to  init_board on the constructor the GPIO pins are not initiallized.

     

    Can you try this ?

     

    #Import piface library
import  pifacedigitalio


#create and initialise pfd object
pfd = pifacedigitalio.PiFaceDigital()

def access_gpio(pin, value):
         pfd.relays[pin].value = value

  • 0 in reply to iagorubio

    i don't initialise the board at this point because it already gets initialised when the pi boot. When i initialiase the board at this point. it will reset the states of the relays.

  • 0

    I would suggest then to take out the auto init at boot time and focus on the code above first, it would be a simple matter to re-establish the auto mode once the debugging is complete. this way you can easily drive the relays on and off manually in order to better understand what is happening

     

    Also did you measure the supply voltages between TP1 and TP2, or on the GPIO connector to see if your experiencing any issues there. I have not seen the schematics for the PI Face so don't know if it is powered from the PI or via a separate adapter. Relays when switching on and off can cause power spikes if suitable protection circuits are not in place, this is why assuming your code is correct, it could be the power issue. make some measurements and let us know

     

     

    thanks