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Nexys Video GPIO
Overview
Features Used
| Not Used | Used | |
|---|---|---|
| 8 user switches | X | |
| 8 user LEDs | X | |
| 128×32 monochrome OLED display | X | |
| USB-UART Bridge | X | |
| 160-pin FMC LPC connector | X | |
| Micro SD card connector | X | |
| HDMI Sink and HDMI Source | X | |
| DisplayPort Source | X | |
| Audio codec w/ four 3.5mm jacks | X | |
| 6 user push buttons | X | |
| User EEPROM | X | |
| 10/100/1000 Ethernet PHY | X | |
| 512MiB 800Mt/s DDR3 Memory | X | |
| Serial Flash | X | |
| Four Pmod ports | X | |
| Pmod for XADC signals | X | |
| USB HID Host | X |
Description
The Basic User Demo project demonstrates a simple usage of the Nexys Video's GPIO and UART. The behavior is as follows:
- The 8 User LEDs are tied to the 8 User Switches. While the centerUser button is pressed, the LEDs are instead tied to GND
- An introduction message is sent across the UART when the device is finished being configured, and after the center User button is pressed.
- A message is sent over UART whenever BTNU, BTNL, BTND, or BTNR is pressed.
- The onboard OLED displays the alphabet then a screen saying “This is Digilent's Nexys Video”
All UART communication can be captured by attaching the UART port to a computer running a Terminal program with 9600 Baud Rate, 8 data bits, no parity, and 1 stop bit.
Prerequisites
Skills
- Basic familiarity with Vivado
- This experience can be found by walking through our “Getting Started with Vivado” guide
Hardware
- Nexys Video FPGA board
- Micro-USB cable
- Nexys Video Power Supply
Software
- Vivado Design Suite 2015.X
- Newer/older versions can be used, but the procedure may vary slightly
Downloads
How to...
1. Generate the Project
1.1) Download the repository linked in the download section and unzip it in the location of your choosing.
1.2) Generate the GPIO project in the Projects folder by following this guide before continuing: How to Generate a Project from Digilent's Github
2. Build the Project
2.1) Click Generate Bitstream on the left hand menu towards the bottom. Vivado will run through both Run Synthesis and Run Implementation before it generates the bitstream automatically.
Note: If you want, you can click each step by itself in the order of Run Synthesis, Run Implementation and then Generate Bitstream.
3. Program the Board
3.1) Once you have generated your bit file, Click on the hardware manager and connect to your board by choosing the local server option.
3.2) Click program to load the project onto your Nexys Video.
4. Run the Project
This portion will help you run the demo and observe all its features.
4.1) Using the Switches with Leds
For this section, all the switches are tied to their corresponding led. Every time a switch is toggled, the led directly above it will toggle with it.
4.2) UART Communication Using the Buttons
To see the UART communication channel, open a terminal program on your computer set to 9600 baud, 8 data bits, no parity bit and 1 stop bit. On startup, the Nexys Video will transmit “Nexys Video GPIO/UART DEMO!”. Whenever a button is pressed, the Nexys Video transmits “Button press detected!”.
4.3) OLED Display
On startup the onboard OLED will display the full alphabet and numbers 0-9. Then after about a second, the OLED will turn off for another second. After this, the OLED will display the message “This is Digilent's Nexys Video”. It may be required to cycle power on the board prior to programming for the OLED to initialize correctly.
