Nexys Video Looper Demo
|8 user switches||X|
|8 user LEDs||X|
|128×32 monochrome OLED display||X|
|160-pin FMC LPC connector||X|
|Micro SD card connector||X|
|HDMI Sink and HDMI Source||X|
|Audio codec w/ four 3.5mm jacks||X|
|6 user push buttons||X|
|10/100/1000 Ethernet PHY||X|
|512MiB 800Mt/s DDR3 Memory||X|
|Four Pmod ports||X|
|Pmod for XADC signals||X|
|USB HID Host||X|
This project demonstrates the usage of the Nexys Video's audio codec and DDR3 memory. The behavior is as follows:
- The looper has 16 'banks' that can contain audio data. The user can record audio tracks to these banks and play them back simultaneously.
- Audio data is constantly sampled at 48 KHz through the Line In input jack and output through the Line out jack.
- When the record button is pressed, the timer on the 7-segment display is started, and the audio data is recorded into one bank.
- If the record button is pressed again, the length of the loop is saved and the audio data is read from beginning to end and mixed with the input signal.
- If the stop button is pressed while recording, the data is overwritten with a blank signal and the data is erased.
- While a bank is playing, the user can record additional tracks on other banks by pressing BTNL or BTNR to select another bank to record to. If the user presses play/record on a bank that is already playing, it will overwrite the audio on that bank.
- Holding the stop button on any specific bank for 1.5 seconds will delete it.
- The OLED shows the state of each bank as well as the current progress of the loop you are in.
- BTNU swaps which selection of banks you are using. SW0 selects which selection of banks you are editing. Leave this in the 'off' position for now. This will be described below.
|BTNL||Back one bank|
|BTNR||Forward one bank|
|SW0||Selects which track you are editing (described below)|
|X||Bank is empty|
|Circle||Bank is recording|
|Right arrow||Bank is playing|
|Square||Bank is stopped|
- Basic familiarity with Vivado
- This experience can be found by walking through our “Getting Started with Vivado” guide
- Nexys Video FPGA board
- Micro-USB cable
- Nexys Video Power Supply
- Headphones or Speakers
- Audio Input device (Aux-In, Guitar, etc.)
- Vivado Design Suite 2015.X
- Newer/older versions can be used, but the procedure may vary slightly
1.1)Plug in your input to the Line in jack on your Nexys Video. Plug your speakers/headphones into the Line out jack. Plug in your Nexys Video and power it on.
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
3.2) 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.
4.7) Canceling a recording
If, while recording, you want to cancel the recording, you can press the stop button and it will erase the bank.
4.8) Erasing an already recorded bank
Hold down the stop button for 1.5 seconds to erase the data on the corresponding bank.
4.9) Using the 'swap track' feature
After recording to several banks, you can quickly swap between two playing states by using BTNU. First, record a few tracks.
Flip SW0 to the up (on) position to see which banks will be playing on the other track. You can then go through and select which banks will play on this other track by scrolling through with BTNL and BTNR and playing or stopping the banks with BTNC and BTND. When your selections are made, switch SW0 back to the off position and press BTNU. A swap icon will show up, letting you know that the track will with switched at the end of the loop.
At the end of the loop, the track number will switch to '1', and the bank selections you made earlier will be played back.
4.10) Resetting the looper
Press the CPU_RESET button to return the device to its initial state.