Udoo Neo Full GPIO Electrical characteristics

Discussion in 'General Discussion' started by Deo Joseph, Mar 31, 2017.

  1. Deo Joseph

    Deo Joseph New Member

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    Hi..
    I am doing a project using Udoo neo full version. i need 48 digital outputs..one of the solution says i can use port expander but What is the maximum current that can be drawn from each GPIO pin?
    and what is the maximum total current that i should not cross when using 48 I/O pis?
     
  2. waltervl

    waltervl UDOOer

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    Hi, this information is unknown as freescale, the manufacturer of the CPU is not releasing this information. See the next discussion with more information: http://www.udoo.org/forum/index.php?threads/3295/

    I would be very conservative and only use a few milli amps per pin. Also the Neo is very sensitive for currents and is easily to stop booting when too much current is drawn from the power pins with 5V and 3.3V. So if you use a lot of pins use an external power source for external devices.
     
  3. Deo Joseph

    Deo Joseph New Member

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    Thank u for the quick reply..
    I need to drive 48 relays..what if i use IC TPL7407L which draws very less current, the data sheet says input current is 10uA (7 of such ICs (7*7=48 outputs)).
    so 48*10uA=480uA=0.48mA(Total current drawn from the board)
    Am i correct?
     
  4. Laura

    Laura Administrator

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    Shift registers are a good way of increasing outputs and inputs, with the 74HC595 commonly used for output (SIPO/serial in parallel out)

    Edited to add: This post was in reply to the opening post, not the relay one just posted.
     
  5. Deo Joseph

    Deo Joseph New Member

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    Thank you..
     
  6. waltervl

    waltervl UDOOer

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    You are talking about micro Amps, I about milli Amps.
    1 milli Amp = 1000 uA so a few milli Amps per pin = a few thousand micro Amps per pin. So your solution will work.

    I did not count the total GPIO of the Neo (M4/A9) combined but perhaps it is possible to get 48 digital outputs. As long as you connect low power relays/switch devices to the Neo you can manage. As long as the relay does not draw more then a few milli Amps.
    To get more IO on the M4 side: http://www.udoo.org/docs-neo/Arduino_M4_Processor/Use_more_digital_pins_on_M4.html
    If you switch off the M4 you can use the IO of the M4 on the A9 side: http://www.udoo.org/docs-neo/Hardware_&_Accessories/GPIO.html

    You could also buy or make something like this:http://microcontrollershop.com/product_info.php?products_id=5622
     
  7. Deo Joseph

    Deo Joseph New Member

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    Hi..
    i would like to control electrical appliances like fluorescent lamps (inductive load).
    Anyone please suggest me which relay should i use?
    Requirements:
    DC controlled relay(5-12V), AC switching(230VAC/20A)
    I need a industry standard highly reliable Electromagnetic relay..
     
  8. sirrab

    sirrab UDOOer

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    See your other post. Not a good idea to double post.
     
  9. jas-mx

    jas-mx Active Member

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    For AC/DC loads this type of board works fine with the neo (have tested), for the AC load you should also be able to use a solid state relay . Remember that the GPIO pins are high by default when the imx6sx is reset.
     
  10. jas-mx

    jas-mx Active Member

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    For 48 pins best to use a port expander, my opinion if you don't require interrupt handling then a port expander supporting i2c (ie MCP23017) is more convenient than shift registers. If you still want to use 48 pins then you might need to review the DSE (drive strengths) when IOMUX'ing the pins to lower the output current.
     

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