Here I have used the concept of Scrolling LED display to make the Valentine Gift beautiful. Different pattern can be display on the display by changing the code in the microcontroller
Step 1: Video for Easy Understanding
Step 2: List of Components
DC adaptar (5v 2 amp) × 1
DC socket × 1
P89V51RD2 controller IC × 1
40 pin IC base × 1
16 pin IC base × 3
Crystal 11.0592 Mhz × 1
Capacitor 33 pf × 1
Capacitor 1000 µF × 1
Capacitor 10 µF × 1
Tectile Switch (4 pin small) × 1
Resistance 10K ohm × 1
Resistance 100 ohm × 24
Connecting Wires × 10
General Purpose PCB (1 feet by 1/2 feet) × 1
5 mm LED: Red × 600
transistor BC547 × 47
IC 4017 × 3
Step 3: Circuit Diagram
As the circuit is complex so I made it in parts and in matrix as well as the circuit is just repeating so I have made continuation dots
Step 4: CODE
The coding is done in EMBEDDED C
Step 5: DISPLAY CONTENT
Using a microcontroller we can change the contents of the display like i have display heart and "I L U" on the LED matrix.
Step 6: DESIGNING LED MATRIX
LED matrix is designed by putting all the positive terminal to the row side and connecting it with the microcotroller by using transistor as switch. The transistor used here are BC547. All the negative terminals of the led are connected in the column and they are also connected with the transistor which is performing as a Switch.
Step 7: Working and Use of IC4017
The negative terminal of LED which were connected to the transistor for switching are switched using IC4017. Actually all the LED can be able to glow parallely. So LED of first column glows first by giving data through positive terminal and negative terminal is grounded by switching through IC4017. IC4017 is a shift register IC which will operate the column one by one and the switching is done so fast that it seems that all the LED are running parellely.
Step 8: Microcontroller and Power Supply
The power requirement is completed by using 5V DC power. This can be battery based to make the project a mobile unit or it can be designed be designed using transformer, diodes for rectifier, capacitor and regulator. Here i have directly used a 5V DC adaptar. The controller used here is P89V51RD2 (8051 microcontroller) which has crystal value of 11.0592 MHz and capacitor 33 pf. the reset section of microcontroller is designed using tectile switch, 10 uf capacitor and 10 k ohm resistance.