Run the Demonstration Standalone (AD7768) - ArrowElectronics/data-storm-daq GitHub Wiki

The DataStorm DAQ development kit can be run as a standalone desktop computer. This hardware configuration requires a keyboard, mouse, and HDMI monitor.

Configuration for standalone IIO Oscilloscope access

The AD7768 Evaluation Platform in this configuration is comprised of the following components:

Analog Devices EVAL-AD7768FMCZ (also Known As EVAL-AD7768) data converter board
DataStorm DAQ (Trenz Intel® Cyclone® V SoC TEI0022 Development Board) (includes 12VDC power supply)
Digilent Analog Discovery 2 Signal Generator with dual outputs
Digilent Discovery BNC adapter board
Two (2) BNC male to SMB Female Cables
Monitor with HDMI input
HDMI cable
Keyboard and Mouse with USB connectors
Separate Windows PC running Digilent WaveForms App

Configure BOOTSEL DIP Switches

Select the SD card as the boot source for the processor.

Configure FMC_VADJ DIP Switches

The FMC_VADJ power rails provide power to the EVAL-AD7768FMCZ via the FMC interface. This is an adjustable voltage. It must be set to 3.3V. Modify the VID_SW DIP switch settings to select 3.3V.

Assemble the Hardware

Follow the steps in the order shown below.

Insert the Micro SD card into the SD card slot
Insert the EVAL-AD7768FMCZ FMC connector into the FMC mating connector on the DataStorm DAQ board
Attach the monitor to the DataStorm DAQ using an HDMI cable
Attach the keyboard and mouse to the DataStorm DAQ using any of the 4 USB ports
Connect the Signal Generator to the EVAL-AD7768FMCZ SMA connectors
Ensure that Jumper LK1 is in position B and LK2 is in position A on the EVAL-AD7768 board, for it to be powered via the FMC connector
Ensure that Jumpers SLP1 and SLP2 are in positions A (default) on the EVAL-AD7768 board

Connect the power supply to the DataStorm DAQ
Plug the AC-DC adapter into an AC outlet

Signal Source

A signal generator with 2 outputs is used to generate the differential signals driving the AD7768 inputs. The AD7768 expects the input signals to swing between AVSS and AVDD1 (+5V on the EVAL-AD7768 board). This means that the user is expected to provide a true differential input centered at VCOM (AVDD1-AVSS)/2 (as in yellow tag #5 below).

Install (if not already done) the Digilent WaveForms App.

Open the WaveForms App and Click on Wavegen in the left margin which opens a waveform window

Click on Channels and select 2
Select Type as Sine
Select Frequency or Period
Set Amplitude to 2V
Set Offset (Common Mode Voltage) to 2.5V
For Channel 2, Match the Channel 1 settings
Select the Phase to 180 degrees for Inverse signal
Click on No synchronization and select Synchronized
Click Run All

Run the demonstration standalone

Power up the unit and wait approximately 60 seconds for the unit to be fully functional.

IIO Oscilloscope automatically launches during the Linux boot process. No further configuration is required, however the application also has a desktop icon in case the user needs to launch the application on demand.

Enable voltage0 ADC channel

Select a Plot Channel to be displayed in IIO Oscilloscope. Click on the check box in the Plot Channel window adjacent to voltage0. Right click on axi-ad7768-adc in the Plot Channels window. Select voltage0 and rising edge as the trigger parameters.

Capture Time Domain Signals

Select an appropriate number of Time Domain samples in the Plot Type window. Press the Capture / Stop button to begin the capture process.

Capture Frequency Domain Signals with Frequency Markers enabled

Change the capture mode to Frequency Domain. Select an FFT Size and Average. Press the Capture / Stop button to begin the capture process.

Right click in the IIO Oscilloscope plot area. Select Single Tone markers. Press the Capture / Stop button to begin the capture process with markers.

Note the information in the Marker window. This capture shows a signal source of 10 kHz with harmonic components.

Run the Example Applications

The LibIIO library API enables access to the converter data from C code, Python code, or MATLAB. A small sample of C and Python codes are provided for the reader and can be run natively on the DataStorm DAQ.

Review the Python source code

Open a Terminal Emulator. To do this, either double click on the 'Terminal Emulator' icon on the Desktop or type CTRL + T.
```
  $ cd examples/python-examples
  $ thunar
```

Review the Python source code

  - Double click on the file ad7768evb.py to review in the text editor
  - Select your preferred channel to obtain readings from that specific channel

Run the Python source code
```
  $ python3 ad7768evb.py
```

This capture shows a signal source of 10 kHz with harmonic components.

NOTE: The following image shows the output data from Channel 0 of the 8 available channels in AD7768. The outputs from other channels can be obtained in a similar method by defining the relevant channel number in the given source code.

Review the C source code

Open a Terminal Emulator. Double click on the 'Terminal Emulator' icon on the Desktop
```
  $ cd examples/c-examples
  $ thunar
```

Review the C source code

  - Double click on the file ad7768-iiostream.c to review in the text editor
  - Select your preferred channel in the CHANNEL_NUMBER constant to obtain readings from that specific channel

Compile the C source code (Use -liio flag to dynamically link the LibIIO libraries)
```
  $ gcc ad7768-iiostream.c -o ad7768-iiostream -liio
```

Run the C executable
```
  $ ./ad7768-iiostream
```

Shutting down the demo

Power down the target. Launch a Root Terminal by double clicking on the root terminal icon. Type the following
```
  $ poweroff  
```
Wait 30 seconds and then you can safely power down the DataStorm DAQ

Return to AD7768 Quick Start Guide