I recently acquired one of the new Arrow SoCKits, which are development boards for Altera's Cyclone V ARM processor / FPGA SoCs. This repository contains a simple example of an FPGA hardware description that flashes the LEDs back and forth, as well as a C program that controls the speed of the flashing. A detailed explanation of the implementation and use of this system can be found in parts I-IV of my Cyclone V Tutorial.
Open the project file "sockit_test.qpf" in Quartus II. Then open the "soc_system.qsys" file in Qsys. Generate the Qsys system and then compile the project in Quartus. You can then program the "sockit_test.sof" file to the Cyclone V FPGA.
With the .sof file programmed, the lights will begin to sweep back and forth. You can control the speed using the FPGA keys. KEY0 will reduce the speed, KEY1 will increase the speed, KEY2 will pause/resume, and KEY3 will reset.
Make sure you have the Linaro "arm-linux-gnueabihf" toolchain installed and run "make" inside the "software/blinker_us" directory. Copy the "blinker" binary over to the Linux partition on your SD card. Boot from the SD card, program the .sof file to the FPGA, and then enable the lightweight HPS-to-FPGA bridge
echo 1 > /sys/class/fpga-bridge/lwhps2fpga/enable
Now you can set the speed of the blinking by running
./blinker delay
The delays range from 1 to 15, inclusive, with 1 corresponding to the fastest speed and 15 to the slowest.