By Koffi Selom Egbeto

amountdollElectronics - Devices

Nov 2, 2013 (4 years and 11 days ago)






This color changing scoreboard works just
like a normal scoreboard, to keep track of
scores during a game or games.

Only difference about this scoreboard is that,
it has to do with different colors changing
LEDs or lights in a scoreboard which makes it
fun and unique.

In this project, a 5 x 7 LED Matrix was used
with a HC08 QG8 series, a 74138 and a
74154 decoder, some resistors and PNP

First this idea came to mind while I left the
gym one day after practice and I kind of
added a little twist to it.

Thought it was going to be a fun and
entertaining project to have a scoreboard
with different colors going on as the scores
change, even though it is giving me a hard
time to work on it.

The way this scoreboard suppose to work is
that when the buttons are pressed, the score
changes, and according to the score, the
lights or LEDs on the Matrix will automatically
change colors due to how high, equal or low
the score is.

Concerning the scores, whenever the game is
going on, the higher score should light up in
“red”, the lower in “green” and if the score is
the same then it should light up “orange or

Here is some calculations used to figure out
some of the resistors. For the red LED I got
100 ohms for R.


(15mA) * R + 1.5v

R= 1.5v/15mA

100 ohms

For the green LED I got 33.33 ohms for R


(15mA) * R + 2.5v

R= 0.5v/15mA

33 ohms

High score= red

Low score= green

Score is tie, color
changes to orange
for both.

Purpose of transistors and more