AD7124 Console Application

Supported Hardware

Supported Devices:

Supported Evaluation Boards:

Supported Carrier Boards:

Introduction

This page gives an overview of using the AD7124 Firmware Example with SDP-K1 EVAL board and AD7124 EVAL board. The firmware example comprises 3 layers of software (from top to bottom): Console Application Layer, Device No-OS Layer and Platform Drivers (Mbed-OS) layer.

The application layer uses the ADI Console Libraries to create console based User Interactive (UI). The middle layer of No-OS device library have device specific APIs to interface with AD7124 device. These APIs allows direct access to device register map in order to read/write device registers. The bottom layer of Platform Drivers is responsible for Low Level Interface. The platform drivers uses mbed-os libraries to access low level peripheral (like GPIOs, SPI, I2C, etc).

The Mbed Platform simplifies the overall software development process by providing the low level driver support. This reduces the hardware dependency as any Mbed enabled board can be used with same firmware with little modifications (precisely changing a pin mapping).

Interface Diagram

The AD7124-EVAL board is connected to SDP-K1 through 120-pin SDP Connector. The AD7124-EVAL board has external connector to connect up-to 8 analog inputs. The board needs to be powered-up through 9-12V external DC supply. The SDP-K1 is connected to PC through USB cable. The firmware can be loaded into SDP-K1 board through this USB interface from PC. The SDP-K1 acts as a Serial Device and firmware loaded into it interacts with any serial terminal (like Teraterm, Putty, Coolterm, etc) by configuring terminal for proper serial settings (COM Port, Baud Rate, etc).

Hardware Connections

Power Supply and USB Connection

A 7V to 9V DC supply (barrel jack, center pin positive) is required to power the EVAL-AD7124-8SDZ evaluation board. SDP-K1 is powered through USB connection to PC. SDP-K1 acts as a Serial device when connected to PC, which creates a COM Port to connect to Serial Terminals like Teraterm, Putty, etc. The COM port assigned to a device can be seen through the device manager for windows based OS.

Analog Inputs

The screw terminal connections to J6 and J11 can be used to connect appropriate analog input signals to provide test stimulus to the AD7124.

The AD7124 device can be software configured to interface with external devices (e.g. sensors). The AD7124 Firmware example provides such 2 configurations (selected through console UI) as described below:

Configuration A:

AIN0/AIN1 are used for channel 0, simple voltage measurement

Configuration B:

AIN2/AIN3 go to the A2 thermocouple connector on the evaluation board, and are captured on channel 0. This uses an internal reference and has a bias voltage enabled on AIN2. A suitable thermocouple should be connected to A2 for this measurement. AIN4/AIN5 are an RTD1000 measurement on channel 1. Excitation is provided from AIN1 for this. This requires an external RTD and reference resistor connected as show in the figure below.

Temperature sensing application using AD7124 can be found here

AD7124 Mbed Firmware

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.

The software execution sequence for the AD7124 Firmware Example is shown below. This is a blocking application as it waits for user input over serial interface (UART). The input is scanned and processed through ‘adi console libraries’. The menu functionality is executed from ad7124_conole_app.c file. The application layer talks with No-OS layer for device registers and data access. The No-OS layer interfaces with Platform Drivers layer for accessing low level peripherals. As name suggests, this layer is platform dependent. AD7124 firmware uses Mbed libraries within Platform Drivers layer. AD7124 Firmware Example is shown below.

Build Guide

Build Prerequisites

Prior to building a firmware project, it is required to set up an environment so that the build process may find the necessary tools (compiler, linker, SDK etc.). Use the following steps to prepare your environment for building firmware projects for respective platform.

  • Clone Precision Converters Firmware repository with the –recursive flag (not needed if building with web IDE for Mbed platform):

git clone --recursive https://github.com/analogdevicesinc/precision-converters-firmware

  • If however you’ve already cloned the repository without the –recursive flag, you may initialize all the submodules in an existing cloned repo with:

git submodule update --recursive --init

  • Install Make in the root of ‘C’ drive without any spaces in the installation path. The path must be C:\GnuWin32\…. Add this path into the system environmental path variable (as shown in below screenshot).

  • Install Git and add a path of C:\Program Files\Git\usr\bin\ directory into system environmental path variable (please verify your git installation path is correct).

  • Install Mbed CLI 1 as per guide here.

  • Install GNU Arm Embedded compiler (for the development, 9-2019-q4-major version is used) and add a path of GNU Arm Embedded Toolchain bin directory into the system environmental path variable (as shown in below screenshot).

  • Configure the compiler location with Mbed CLI. This can be carried out by running the mbed config -G GCC_ARM_PATH <path-to-your-gcc-compiler> in Command Prompt. For example you can run mbed config -G GCC_ARM_PATH “C:\Program Files (x86)\GNU Tools ARM Embedded\9 2019-q4-major\bin” in command prompt. It will set mentioned compiler path to all the Mbed Projects.

Building a project

Once the build enviornment is setup, follow the guide below to build your project and generate executable file (.bin/.hex)

  • Clone the Precision Converters Firmware repository into Keil Studio using “File->clone…” menu.

  • Once the project repository is imported, wait until all library dependencies are imported as shown in below screenshot. Now, open the ‘.medignore’ file present in the root directory of repository. Add comment syntax (two forward slashes) in front of the project name which you want to build. This will ignore all other projects and build only the comment syntax selected project.

  • Select the target device (default used for development is SDP-K1) and click on ‘Clean build’ option to build the project. After a successful build a binary will be downloaded to your computer- store this on your drive. Drag and drop this binary to the USB drive hosted by your controller board to flash the MCU.

Note

If you intend to build different project, then modify the .medignore file in the root directory as mentioned in step2 and clean build project as mentioned in step3

  • Open Git bash and change current directory to project directory (eg. precision-converters-firmware/projects/ad4130_iio directory) which you want to build.

  • Type make on the git bash command prompt to build a project.

  • After successful build, binary file will be created into the Project_Name/build directory.

  • If you want to clean build, type make reset on git bash command which deletes all generated build files for the given project.

Note

Default TARGET_BOARD is SDP_K1 and COMPILER is GCC_ARM. Current Make based build only support GCC_ARM Compiler.

  • By default project is built for “SDP_K1” Board and “GCC_ARM” Compiler. If you want to build for other Mbed Board, For example If you want to build the project for “DISCO_F769NI” Board then run make TARGET_BOARD=DISCO_F769NI command in git bash command prompt. If you want to clean build, run make reset TARGET_BOARD=DISCO_F769NI command to delete the generated build files for the given project.

  • Open the respective project directory by navigating into the “precision_converters_firmware/projects/” folder.

  • In the “STM32” folder present within the project directory, double click and open the .ioc file present within.

  • Click on the “Generate Code” option seen on the top right corner

  • Upon successful generation of drivers for the selected MCU, the autogenerated files would be seen in the same directory where the .ioc file was present. Double click and open the “.project” file seen in the list of files

  • After the project is loaded to the STM32CubeIDE, unfold the adxxxx_iio project seen in the project explorer, right click the “app” folder, select “Settings” under the “C/C++ Build” section on the left pane and un-check the “Exclude resources from build” checkbox. This would ensure that the project specific files are included by the build system

  • In order to choose STM32 platform in the firmware, select the “ACTIVE_PLATFORM” as “STM32_PLATFORM” in the app_config.h from the respective project. Alternately , add compiler flag “ACTIVE_PLATFORM=value of STM32_PLATFORM in app_config.h” for selecting stm32 platform.

  • Add compiler flags “-u _printf_float” to the project settings.

  • Program by clicking on the “Run adxxxx_iio” option seen or by performing a copy->paste option of the .hex file seen in the STM32/Debug folder

Running a project

Once the firmware build is successful and binary file is generated, copy the generated binary into USB drive hosted by your MCU board (e.g. USB drive hosted by SDP-K1 board on windows). This will flash the binary file into MCU present on the controller board. Programming might vary based on the tools used for building a project. The ‘Project Build’ section above talks about this exception at the end of all build steps.

Quick Start

If you have some familiarity with the Mbed platform, the following is a basic list of steps required to start running the code, see below for more detail:

  • Connect the AD7124 EVAL-board to the SDP-K1 controller board.

  • Connect the SDP-K1 controller board to your computer over USB.

  • Follow the steps mentioned in the Build Guide section above.

  • Start up a serial terminal emulator (e.g. Tera Term)

    • Find the com-port your controller board is connected on and select it.

    • Set the baud-rate for 230400

    • Reset the controller board and connect.

  • Use the menu provided over the terminal window to access the evaluation board.

Using the Firmware

The AD7124 firmware example is configured to have following serial settings:

Baud rate: 230400 Data bits: 8-bits Parity: None Stop bits: 1

Configure your serial terminal (Tera Term) for below settings:

The AD7124 Main menu looks like below (with Tera Term):

The firmware is designed to be intuitive to use, and requires little explanation, simply enter a number corresponding to the required command and follow the on-screen prompts.

The console menu application provides the following main features:

  • Enable/Disable individual ADC channel (0-15).

  • Connect analog input pins to individual channel.

  • Configure the device setup (0-7) and assign to individual channel (0-15).

  • Display device and channel setup.

  • Perform internal device calibration.

  • Read die temperature (using internal temperature sensor).

  • Read/Write device registers.

Support

Feel free to ask questions in the EngineerZone