Run the Demonstration (AD738x) - ArrowElectronics/data-storm-daq GitHub Wiki

Run the Demonstration

Signal source
Run the demonstration locally
Run the demonstration via ethernet

Signal Source

The AD738x requires a Differential signal from a signal source. AD738x accepts input voltage from GND to VCC centered around VCM=(GND-Vref)/2, and differential input full voltage swing equal to Vref, above which ADC conversion will saturate. The AD738x, in its default configuration, is setup with Vcc equal to +3.3V. Vref can be set to +2.5V / +3.3v from onboard supply(jumper LK4) or through internal Vref. Here Vref set to +3.3V external so AD738x requires the input signal to be centered around VCM equal to (Vref/2 i.e +3.3V/2) which can be externally given through VCM input on EVAL-AD738x-FMCZ. Connect the Differential signal source to AinA+ and AinA- input of AD738x. Give external noise free variable VCM supply to VCM input & adjust it in range 1V to 2V for better output in FFT plot. A single ended signal generator with 2 outputs can be used to generate the differential signals driving the AD738x inputs by setting second output to track first output in inverted mode on a signal generator.

Run the demonstration standalone

Power up the unit using this hardware configuration. Wait approximately 60 seconds for the unit to be fully functional.

IIO Oscilloscope will be automatically launched on the system desktop. No configuration is required.

Note: The snapshot demo image are based on AD7380, But similarly it can be applicable for other AD738x platforms.

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 ad7380 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.

Shutting down the demo

Power down the target. Launch a Root Terminal. Type the following
```
  $ poweroff  
```
Wait 30 seconds and then you can safely power down the DataStorm DAQ

Run the demonstration via ethernet

Define the host PC IP address

A wired ethernet point-to-point connection between the host PC and the embedded target is required. Use this link for instructions on how to assign a static IP address to the host Ethernet adapter. Set the following values

IP address : 192.168.0.1
Subnet mask : 255.255.255.0
No entries required for the other fields

Connect to the target terminal

A wired Micro USB serial port connection between the host PC and the embedded target is required
Launch a linux terminal (like Tera Term VT or Putty) and connect using serial port
Select 115200 baud
Select the appropriate target COM port

Define the target IP address

Type the following at the terminal prompt to set the target IP address

$ ifconfig eth0 192.168.0.2 up

Launch IIO Oscilloscope

Note: IIO Oscilloscope creates a .osc_profile.ini file in the Users/UserName/Appdata/Local directory. The next time IIO Oscilloscope is opened, the existence of this file delays connection to the target. It is recommended to delete the .osc_profile.ini (if it exists) prior to launching IIO Oscilloscope.