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Home › Forums › The libraries hosted on the site › PCF8574 i2c digital I/O expander › PCF8574-transistor base switch
Tagged: Arduino, npn, pcf8574, transistor
Hi @xreef,
Thank you for this great library and all the effort you did.
I am having difficulties to drive a transistor using the PCF8574 GPIO as a basic switch. My objective is to turn on and off audio lines using the bjt driven by the expender.
I would like to request for sample/example schematic or circuit you use to connect a transistor to the expander.
Thank you in advance
Hi tsctrl,
here a schema with a simple npn transistor to light a led.
Bye Renzo
Hi, this works fine with an LED but I’m having trouble driving a 12V motor using the npn as a switch to complete the ground. Any idea why this would happen?
Hi Celeb10,
I think the transistor isn’t sufficient to control a 12v motor, you need more ampere, try to use a MOSFET.
Bye Renzo
thanks Bye Renzo
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