Introduction: Arduino LED Display With Bluetooth Control

In this instructable, we will be making 32X8 LED Matrix display that will have the functionality of changing the Text Message with our smartphone in real time and will make our own the app using MIT App Inventor.

So, friends lets get started with this cool and awesome project.

Step 1: Designing Our PCB on Fritzing

We have designed the PCB on Fritzing, which is an open-source hardware initiative that makes electronics accessible as a creative material for anyone.

It is a 2 layered PCB design where we have perfectly packed our required stuff very neatly.

Now it is time to export the Gerber file and order our PCBs.

Step 2: Order Our PCBs at Very Low Cost From JLCPCB

Once, you have created the zip folder of your PCB's Gerber file.Now, it is the time to upload the file to JLCPCB and make the requirements accordingly like selecting the masking as black, which i have did for my PCBs. If, you are looking for the best quality PCBs for your projects than JLCPCB is the best option to go for.

They are offering 10 PCBs for just 2$ with shipping extra and I find it as the best deal available.

So, Where to prototype 10 PCBs for $2 only:

Step 3: Components Required :

  • Arduino (NANO or UNO)
  • Bluetooth module HC-05
  • LEDs ( 32X8= 256 pcs)
  • MAX7219 LED matrix driver IC ( 4 Pcs)
  • 10uF capacitor ( 4 pcs)
  • 100nF capacitor ( 4 pcs)
  • 40K Resistor (4 pcs)
  • Connectors, solder, wires, tools, etc...

Step 4: Working

Here, we have created 4 matrices each of 8X8 LEDs. Each MAX7219 driver can handle a 64 LEDs matrix. The Arduino will send the data using a serial communication. So we have to connect the clock and load pins from the Arduino to all MAX7219 drivers. The data pin will be only connected to the first driver. From the "data out" pin of the first driver, we will connect a wire to the second "Data" of the second driver and so on. That's how we connect four 8x8 matrices in series. We should also connect the Bluetooth module to the Tx and Rx pins of the Arduino and supply 5V to it and to each of the MAX7219 drivers.First, let's take a look on how to connect each of the 8x8 matrices. Once we have our 4 matrices we can join them together with the "data out" "data in" pins.

Step 5: Connecting the Data Out ( Pin 24) to the Data Input (Pin 1 ) of Other IC

Step 6: Make the Connection of Clock and LOAD Accordingly

Step 7: Connect the Capacitor and Resistor As Shown in the Diagram

Step 8: Make the Connection of the Matrix Pins As Shown in the Diagrams

Step 9: Making the Case for Our LED Display

Once, you have made the above connection it is time to make a case for that I have used a scrap cardboard and have made a box out of it with a Plastic over the LEDs so that the brightness does not diffuse and give us a more soothing view.

Step 10: Link for the Code and App

Code : Download\

PCB Design : Download

App Files : Download

Step 11: