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arduino to controll LCD brightness on a screen that has buttons?

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  • arduino to controll LCD brightness on a screen that has buttons?

    hey. i know there is a simmilar thread, but my case is a bit diferent.
    In my car, i have a 15.6 lcd monitor (originated for desktop pc), that has its brightness controlled, via the buttons on its panel (like any other screen). the think is, its reather hard, having to press all the buttons all the time... anyone got any idea on this?? the buttons are conected to the lcd controller with 6 small cables..

  • #2
    There are many types of solutions available using an arduino. The hardest part would be accessing the contacts on the back of the necessary buttons to break out leads to attach to the arduino.
    You could use an IR sensor to make the controls accessible to a simple IR remote.
    Also you could use one of many types of light sensors to even automate dimming based on light level in the vehicle. The arduino would not be able to sense what state the monitor menu was in so you would have to experiment with timers in the code to handle the multiple external button presses to build sort of a "macro" for brightness up and down.


    • #3
      my case is fair simple. if the menu is not up, and you press a button, the brightness goes up. other button it goes down. accesing the leads is prety easy for me. the question is, from the 6 cables, one is for each button? and what about the led?
      Last edited by settra; 07-18-2013, 12:09 PM.


      • #4
        Can you get to the solder connections on the back of the buttons? The easiest way to remote a button is to solder a wire to each side of the button. It does not matter what goes in or out of the button. A button just supplies a connection between two contacts when pressed. You could use a transistor to make or break the connection for each button. It would be exactly the same as pressing the button. You could even use a couple of small relays if you are not comfortable with transistors. Then just use two digital outputs of the arduino to fire the transistors or close the relays. You could use an analog input to read a simple photocell to determine when the buttons need to be "pushed" with a delay to hold them long enough to make enough change in brightness. Get a sample from the photocell during a lighting condition where you would want to brighten or dim the display and use those values to trigger the buttons. You could also take note of the range of output of the photocell from high to low light and divide the range into steps. Then trigger a single button push up or down based on the direction of change to determine which button to press each time a different step value is reached. This would give you a wider range of automatic brightness adjustment.