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Using common household items, we’ll build an RGB LED Matrix to display some data. Among the many DIY and hobby projects involving the Arduino, LED Matrix is a fan favorite. Many students and enthusiasts include building an RGB LED Matrix on their wish lists of Arduino projects.

For example, an LED matrix can be used to create a signboard with a scrolling message, to show an animation, to show the frequency spectrum of music in time with the visuals, and so on. Creating an RGB LED Matrix is a lot of fun because of all the steps involved, from designing the circuit to building the matrix to assembling the components to writing the code.

To create your own 86 RGB LED Matrix, all you need is an Arduino Nano, an HC-06 Bluetooth Module, and an Android phone running a special app. To that end, let’s dive right into constructing your very own RGB LED Matrix.

Please Take Notice that Alexandar AS5’s work served as the inspiration for this guide.

Circuit Diagram

The RGB LED Matrix project circuit is shown here. In the first picture, you can see the wiring for the shift registers, the Arduino Nano, the source transistors connected to the columns (with the assumption that they are controlling Common Anode RGB LEDs), and the sink transistors connected to the rows (Cathodes).

The second picture here illustrates how the RGB LEDs are laid out. Cathode terminals take up 8 rows, and anode terminals, 6 columns. Additionally, there are three cathode terminals for red, green, and blue LEDs in each row.

Components Required

• Arduino Nano
• Bluetooth module HC-06
• 48 X Common Anode RGB LEDs
• 6 X BD136 power PNP Transistors
• 30 X BC337 NPN Transistors
• 4 X 74HC595N Shift Register IC
• 36 X 10KΩ Resistors (¼ W)
• LM35 Temperature Sensor
• Power supply
• A lot of wires and materials like plywood and polystyrene sheet

74HC595N

The 74HC595N is a shift register with output latches that can take serial or parallel inputs and outputs. Four of these ICs are used to simulate a 32-bit shift register for this application. This integrated circuit’s job is to change serial data to parallel data so that more digital output pins can be obtained; these pins are then connected to transistors that power RGB LEDs.

Bluetooth Module HC-06

If you’re working on a cool Android-based project, this module is a must-have.

Since the logic is 3.3V and the circuit operates on 5V, a voltage divider made up of two resistors is recommended.

LED Strip

Below is an example of the RGB LED strip we used for this project; it has 30 individual LEDs and is 5 metres long. Each segment of the LED strip needs to be cut in half so that it can function as a single pixel. Using an LED strip will result in an extremely luminous display.

How to Build the RGB LED Matrix?

We’ll now examine the RGB LED Matrix’s assembly procedure in detail. Here, we’ll begin with the RGB LED Strip. Below is a diagram of where to cut the LED strip containing the three individual LEDs (one each of red, green, and blue).

Next, remove the tape, paste each pixel (consisting of three LEDs on the LED strip), and drill tiny holes through the R, G, B, and V+ metal contacts.

Connect the other side of the board by soldering contacts and using short wires, and then secure it with hot glue. Then, join every single row and column together.

Bulkheads of the same material, but painted white to reflect light, can be used to divide each individual pixel.

The connections between rows and columns have been moved to the other side and are displayed here.

Use paper to print the circuit, then trace it onto a PCB and make tiny holes at the indicated locations.

Install the parts on the PCB in the order shown.

Remember that the Arduino Nano has a +5V auto selector, so you don’t have to worry about damaging the controller.

Below is a final depiction of the interior. Take note that all of the necessary plugs, including those for power, Bluetooth, and USB, are conveniently located at the panel’s top.

As a final step, bring the polystyrene sheet to the front of the matrix and place it on the screen’s surface. This is roughly the final form of the RGB LED Matrix.

Create an APP for Android using MIT App Inventor 2

We need a specialized app developed so that the RGB LED Matrix can be managed from an Android device. We’ll be utilizing MIT’s App Inventor 2, a free, web-based app creation tool for Android devices, for this.

 Conclusion

I hope you find this Simple DIY RGB LED Matrix Project useful. MATHA ELECTRONICS will be back soon with more informative blogs soon.