tom303 Posted September 24, 2002 Report Share Posted September 24, 2002 How can i add LED's for the 4 menu buttons?best regards,Thomas :-/ Quote Link to comment Share on other sites More sharing options...
LO Posted September 25, 2002 Report Share Posted September 25, 2002 What do you want them to do?? just flash once when you press the button? or ??What would be the point? :D Quote Link to comment Share on other sites More sharing options...
tom303 Posted September 25, 2002 Author Report Share Posted September 25, 2002 Sorry, they are the 4 additional buttons for shortcuts and yes they should flash once when pressed. ;) Quote Link to comment Share on other sites More sharing options...
ThomasT Posted September 30, 2002 Report Share Posted September 30, 2002 Are there any other basic conditions? E.g. all buttons switch to ground. Want to use the same PCB layout (button and LEDs) like the normal buttons with LED. (meas all buttons all LEDs on together on ground)Just build a little circuit where the output is 0V when button is pressed and a led lights. When button is not pressed 5V should be on the output. Is an digital input so not exactly 5V and 0V are requiered. That makes circuit design more easy. You need at least one transistor for inverting (LED is on when 0V is on output). Or you invert the menubuttons with software modification. (not easy...easy, but not easy to find where....) Quote Link to comment Share on other sites More sharing options...
Guest rebelrob Posted October 1, 2002 Report Share Posted October 1, 2002 Another way to have the output 0v when the button is pressed is to have somthing like this-5v__# 10k res#|__________Vout- | button-||___gnd Quote Link to comment Share on other sites More sharing options...
ThomasT Posted October 1, 2002 Report Share Posted October 1, 2002 Hi rebelrob!What you have drawn is the normal way to connect a button. But he wants that a LED lights when the button is pressed. I have done this while using analog inputs as button inputs. There are no LEDs too. So I have done this with some transistors and with some flipflops (74HC74, for toggle mode). Quote Link to comment Share on other sites More sharing options...
ThomasT Posted October 2, 2002 Report Share Posted October 2, 2002 The simples way would be (I did not test it!): I try to discripe it because ASCII-art works not so good with a propotional font. simply place the LED with a 220Ohm resistor on the place of the original 10k pull-up. That this works as a a pullup resistor you need to add a 10k parallel to the LED. When the button is closed the input is grounded and a current flows through the LED and it lights. Quote Link to comment Share on other sites More sharing options...
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