RGB LED battery powered (rechargeable) Matrix Text Scroller
Teachers! Did you use this instructable in your classroom?
Add a Teacher Note to share how you incorporated it into your lesson.
Step 1: Crazy Idea
okay fine, I've seen a lot of scrollers around, none is RGB. due to boredom, i went and got some stuff to build it.
Step 2: Material
Shift register 74HC595 (x2)
Decade counter CD4017 (x1)
RGB led 4 pins common positive (x100)
Arduino Nano (x1)
1 KOhm resistors (x6)
NPN transistors 2N3904 (x6)
DIP Switch 9 modules (x2)
Hot glue gun
Rechargeable 7.4V 1500mah NiCd battery (any battery between 7V and 15V will do a good job)
Resin or Plastic or whatever you can get to hold LEDs (i cut mine using Laser and 3 mm plexi)
Huge coffee (x3) prefered black (no sugar, no milk, no nothing)
Step 3: Assemble the "Screen"
Using Super Glue, i glued LEDs into the plexi board I've got earlier.
Then, using cooper wires amd soldering iron, i connected positive poles in order to connect it later on to Shift register output.
Remember, Shift Register (positive) Decade Counter (Negative).
Now, Screen is ready.
Step 4: Circuit Preparation and Assembly
After soldering Positive poles vertically of the LED (longest), solder each color (other poles) horizontally, in order to connect it later on to the decade counter.
I used jumper wires to connect columns to the shift register and CAT 5 cables for rows connection to the decade counter.
Now, each output of the Decade counter is used 3 times. using the Fork theory ( 1 input, many output. in my case, 1 input, 3 outputs).
each output of the decade counter is connected to 3 ports of the DIP switch, and using jumper wires, i connected for example, pin 1 to pin 2 and pin 3 of the DIP switch. Switch will manually change color of each row.
Step 5: NPN Transistors and 1KOhm Trick
Since the breadboard I'm using has a limited pin number, i had to go for a soldering trick between NPN transistors and 1KOhm resistors, so i soldered the resistor to the Collector pin (Middle pin) of the NPN transistor, in order to save pins.
Clever, but time consuming.
Emittor pin to the DIP switch, Collector from the decade counter, Base to Negative.
Step 6: Last Assembly
using an old schematic and an old program that i already used to build a huge 150cm × 60cm scroller, i assembled it the same way.
The only tweak was in the DIP switch.
(I will post the code and schematic later)
Et Voilà, a RGB LED scroller is born.
(Happy dancing Happy dancing Happy dancing)
Wait !!! where is my COFFEE !!!
Step 7: A Color-Mix Preview Hehehe
And it is working !!! (ignore the cigarette holder up there hehehe)