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NOTE: This project is currently under construction.
Nexys 4 XADC Demo
Overview
Features Used
| Not Used | Used | |
|---|---|---|
| 16 user switches | X | |
| 16 user LEDs | X | |
| Two tri-color LEDs | X | |
| 5 User Push Buttons | X | |
| Two 4-digit 7-segment displays | X | |
| 4 Pmod ports | X | |
| Pmod for XADC signals | X | |
| 12-bit VGA output | X | |
| USB-UART Bridge | X | |
| Serial Flash for Application Data | X | |
| USB HID Host With Mouse | X | |
| USB HID Host With Keyboard | X | |
| Micro SD card connector | X | |
| PWM audio output | X | |
| PDM microphone | X | |
| 3-axis accelerometer | X | |
| 16Mbyte CellularRAM | X | |
| Temperature sensor | X | |
| 10/100 Ethernet PHY | X |
Description
This simple XADC Demo project demonstrates a simple usage of the Nexys 4's XADC port capability. The behavior is as follows:
- The 16 User LEDs increment from right to left as the voltage difference on the selected XADC pins gets larger.
- The two seven segment displays show the voltage difference on the AD11 pins in volts.
- sw0 and sw1 select which channel to read from
Prerequisites
Hardware
- Nexys 4 FPGA board
- Micro-USB cable
- Wires and a voltage to measure
Software
- Vivado Design Suite 2016.4
- Newer versions can be used, but the procedure may vary slightly
- Nexys 4 Support Files
- These files will describe GPIO interfaces on your board and make it easier to select your FPGA board and add GPIO IP blocks.
- Follow the Wiki guide: Vivado Board Files for Digilent 7-Series FPGA Boards on how to install Board Support Files for
Downloads
How to Build and Program
You will need…
1. Vivado installed on your computer
2. Nexys4 board from digilent
3. Wires and a voltage to measure
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 XADC 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 Nexys 4
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.
After your board is connected, just click program to load the XADC demo onto your Nexys 4.
Running the Nexys 4 XADC Demo
This portion will help you run the demo and observe all its features.
4.1) Applying a voltage to the XADC port
For this demo, the AD11P and AD11N pins are used on the JXADC header. We hooked up a signal generator to our pins. All of the other pins were grounded to avoid coupling.
2. Seven Segment Display and LEDs
The 7-Segment display shows the current voltage across the selected xadc pins. The LEDs turn on from right to left as the input voltage increases.
4.3) Selecting a channel
To display a different channel on the display and LEDs, change sw0 and sw1 to the desired channel.