AVR Multimedia Board

When I was able to produce a beep tone using a microcontroller for the first time, I was very proud of myself. Later, I learned how to interface an LCD module to a microcontroller. Those were the days when I was just starting to step into the world of microcontrollers and the little accomplishments that I had always drove me to learn and do something better.

I love sound and graphics very much. I love it even better if I make them work with microcontrollers. That is why I said to myself that I want to build a microcontroller with a touchscreen TFT LCD module and an audio driver. That way, I would be able to do a lot of projects that involves sound and graphics. Hence, the AVR Multimedia Board was born.

The AVR Multimedia board is a microcontroller board based on a 40-pin AVR microcontroller with a TFT LCD module and an audio driver. For this board, I am using ATmega164P but it is also compatible with other 40-pin AVR devices like ATmega16, ATmega32, ATmega324, ATmega644, ATmega1284, etc.

The TFT LCD module includes a touchscreen panel and a SD card slot. It is driven by ILI9325 and it is configured to a 16-bit interface. I got the TFT LCD module with 16-bit interface from ebay. I also own a couple of similar TFT LCD modules with an 8-bit interface that I got from Iteadstudio.

The audio circuit consists of a 5th-order, low-pass Chebychev filter and a unary-gain amplifier. It is based on the circuit from the application note “AVR335: Digital Sound Recorder with AVR and DataFlash” .

This board won’t be complete if there is no demo firmware. I wrote a couple of demo firmware to test some of the features of the AVR Multimedia Board. You can see the video of my project in action below.