Hello FPGA lovers! Today’s post is an interesting one which helps us visualize the audio spectrum with the help of your FPGA and an LED strip. Using a VGA cable, the spectrum can be visualised in a computer monitor as well. The microphone on the FPGA used (you may need to adapt this to your own board) captures the surrounding sounds and uses the FPGA to convert it into a perceivable visual output. The author has explained the principle of working in step 2. The input audio signal is stored in 2 block RAMs. The 1st RAM consists of the time domain representation which is used for display in the VGA. The 2nd RAM consists of the Frequency domain representation using FFT which is displayed both in the VGA and the LED strip.
The Hardware required for this project is a FPGA board, USB A to B micro cable, VGA cable, 30 LED Strip, VGA display (PC monitor) and 3 male to male jumper wires. The author has used the PC monitor as the VGA display for this project. However you can use a dedicated LCD screen or any other VGA display if you choose to. The hardware connections are explained in step 3.
The code is available as a zip file in step 4. The author has dedicated steps 4 and 5 towards installing and generating the program for the board. The language used is VHDL and the code has been broken down into modules. The zip file consists of the source files, a readme file explaining the code, a .tcl file to automatically build the project and the .bit and .bin files for programming the FPGA.