MEET
HI-FIVER-P. Our finger-counting LEDs kit is based on 10
bit counter. Using the push button switch as a clock
generator consequently increases the 10 bit counter by one,
therefore lighting the next LED. Since we wire pin 5 to the
counter RST (reset) pin (pin 15), when the counter reaches the fifth
position it automatically goes back to the first position when
next button is pressed. i.e. lights the
first-finger LED...
We use
a NPN transistor, together with an RC circuit, to de-bounce the push
button switch. This basic kit can work with many
conventional NPN transistors i.e. 2N3904, 2N4401, 2N2222, etc.
RLX
resistor determines the 5 LEDs brightness and limits the
current flow to about 10 to 15mA when running between 9V to 12
VDC.
The
HI-FIVER flash running rate is determined by the push button
press rate.
|