Arduino Bluetooth controled 8x32 LED matrix

Schematic ATmega328

We've seen the schematic for an Arduino UNO. But I want to use the ATmega328 chip directly on to a PCB. For taht we have to add the chip and all the extra components that make the microcontroller work such as the crystal oscilator and the oscilating capacitors. Also we have to add a 5V voltage regulator.



As voltage regulator I've used the AMS1117 5V voltage regulator with two capacitors to filter the noise. We add 6 female pins for the FTDI module. Add a 0.1uF cap between DTR and reset pin of the ATMEGA328. Connect the RX and TX pins for the bluetooth module as well. Add 4 female pins for this as well. Connect the Data, clk and load pins to the MAX7219 driver. Connect the first driver to the first 8x8 matrix and the Data out pin to the next driver and so on.

Programming the ATmega328

If you use the Arduino UNO or NANO just download the code below and upload it to the Arduino. Remember to disconnect the Tx and Rx pins from the bluetooth module while uploading the code.

If you use this same ATmega328 on a PCB you have to make sure that it already has a BOOTLOADER burned to it. If you want to see how to burn a bootloader to an ATmega chip just check my next video.



Now that the atmega chip has the bootloader we can upload the code using the FTDI module. Connect the FTDI as shown in the schematic above. Open Arduino IDE and open the next code:

The code:

You should also dwonload the LED control library from the next link:

To install open Arduino IDE, go to sketck, add library, add .zip library and open the downlaoded .zip file.