This page gives an overview of using the ARM Mbed platform supported firmware example with Analog Devices EVAL-CN0540-ARDZ Evaluation board(s) that contains AD7768-1 and SDP-K1 controller board. This example code leverage the ADI developed IIO (Industrial Input Output) ecosystem to evaluate the AD77681 device by providing a device debug and data capture support.
The AD7768-1 is a low power, high performance, Σ-Δ analog-to-digital converter (ADC), with a Σ-Δ modulator and digital filter for precision conversion of both ac and dc signals. The AD7768-1 is a single-channel version of the AD7768, an 8-channel, simultaneously sampling, Σ-Δ ADC.
IIO oscilloscope is used as client application running on Windows-os, which is ADI developed GUI for ADC data visualization and device debug. The interface used for communicating client application with firmware application (IIO device) is UART (Note: SDP-K1 can also support high speed VirtualCOM port @1Mbps or higher speed for faster data transmission). The firmware application communicates with IIO device using ADI No-OS drivers and platform drivers low level software layers. SDP-K1 is used as controller board, on which IIO firmware application runs and using above software libraries, the IIO firmware communicates with IIO device.
For data transmission to IIO client, VirtualCOM Or UART serial communication is used. SDP-K1 by default uses the VCOM serial interface for higher speed data transmission.
SDP-K1 is powered through USB connections from the computer. SDP-K1 acts as a Serial device when connected to PC, which creates a COM Port to connect to IIO Oscilloscope GUI running on windows-os. The COM port assigned to a device can be seen through the device manager for windows-based OS.
SDP-K1 can support high speed VirtualCOM port USB interface, so by default VCOM is configured as default interface in the firmware. The interface can be set to UART by defining macro “USE_PHY_COM_PORT” in the app_config.h file.
*Note: Actual COM port number for your device may not be the same as shown above. Therefore, always check your SDP-K1 serial COM port number before connecting to IIO client.
This section briefs on the usage of MBED firmware. This also explains the steps to compile and build the application using mbed and make based build.
Source code is hosted here:
Build Guide for Precision Converters MBED firmware (Use below link):
This library provides an abstracted library interface to communicate IIO device and IIO client application (IIO Oscilloscope) without worrying about the low level hardware details. Download and install below Libiio windows installer in your computer.
Libiio installer for Windows (Use below link):
This is a GUI (Graphical User Interface) based IIO client application for data visualization and device configuration/debugging. The data from IIO devices (ADCs/DACs) is transmitted over Serial/Ethernet/USB link to IIO Oscilloscope client through the abstracted layer of “libiio”. Download and install below IIO Oscilloscope windows installer in your computer.
IIO Oscilloscope installer for Windows (Use below link):
This is a GUI (Graphical User Interface) based IIO client application for data visualization and device configuration/debugging. The data from IIO devices (ADCs/DACs) is transmitted over Serial/Ethernet/USB link to IIO Oscilloscope client through the abstracted layer of “libiio”. Download and install below IIO Oscilloscope windows installer in your computer.
IIO Oscilloscope installer for Windows (Use below link):
DMM tab can be used read the instantaneous voltage applied on analog input channels. Simply select the device and channels to read and press start button.
To capture the data from AD7768-1 IIO device, simply select the device and channels to read/capture data. The data is plotted as “ADC Raw Value” Vs “Number of Samples” and is just used for Visualization. The data is read as is from device without any processing. If user wants to process the data, it must be done externally by capturing data from the Serial link on controller board.
This file can be used to:
This file can be used to:
This file defines the user configurations for the AD7768-1, such as SPI parameters (frequency, mode, etc) and other init parameters used by No-OS drivers to initialize AD7768-1 device (e.g. Power Mode, Conversion mode, etc). These are the parameters loaded into device when device is powered-up or power-cycled.
This file defines getter/setter functions for all the device and channel specific attributes (related to AD7768-1 devices) to read/write the device parameters. The majority of device specific functionality is present in this module.
This file defines the data capture implementation of AD7768-1 for visualizing adc raw data on IIO oscilloscope.
The no-OS drivers provide the high level abstracted layer for digital interface of AD7768-1 devices. The complete digital interface (to access memory map and perform data read) is done in integration with platform drivers.
The functionality related with no-OS drivers is covered in below 2 files: