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AD7980 - Microcontroller No-OS Driver
Supported Devices
Evaluation Boards
Overview
The AD7980 is a 16-bit, successive approximation, analog-to-digital converter (ADC) that operates from a single power supply, VDD. It contains a low power, high speed, 16-bit sampling ADC and a versatile serial interface port. On the CNV rising edge, it samples an analog input IN+ between 0 V to REF with respect to a ground sense IN−. The reference voltage, REF, is applied externally and can be set independent of the supply voltage, VDD. Its power scales linearly with throughput.
The goal of this project (Microcontroller No-OS) is to be able to provide reference projects for lower end processors, which can't run Linux, or aren't running a specific operating system, to help those customers using microcontrollers with ADI parts. Here you can find a generic driver which can be used as a base for any microcontroller platform and also specific drivers for Renesas platforms.
HW Platform(s):
Driver Description
The driver contains two parts:
The Communication Driver has a standard interface, so the AD7980 driver can be used exactly as it is provided.
There are three functions which are called by the AD7980 driver:
SPI_Init() – initializes the communication peripheral.
SPI_Write() – writes data to the device.
SPI_Read() – reads data from the device.
The following functions are implemented in this version of AD7980 driver:
Function | Description |
unsigned char AD7980_Init(void) | Initializes the communication peripheral. |
unsigned short AD7980_Conversion(void) | Initiates conversion and reads data. |
This version of AD7980 driver uses the CS Mode 4-Wire, without Busy Indicator mode; the device has to be connected to an SPI-compatible digital host as following:
The AD7980 CNV signal (C2 on the oscilloscope) has to be connected to the
SPI MOSI signal.
The AD7980 SDI signal (C1 on the oscilloscope) has to be connected to the
SPI CS signal (Chip Select has to be controlled manually).
The AD7980 SCK signal (C4 on the oscilloscope) has to be connected to the
SPI SCK signal.
The AD7980 SDO signal (C3 on the oscilloscope) has to be connected to the
SPI MISO signal.
Signals generated by the driver on the SPI port
Downloads
Renesas RL78G13 Quick Start Guide
This section contains a description of the steps required to run the AD7980 demonstration project on a Renesas RL78G13 platform.
Required Hardware
Required Software
Hardware Setup
A PmodAD4 has to be connected to the PMOD1 connector.
Software Setup
With the Applilet3 for RL78G13 tool the following peripherals have to be configured:
CSI10 (Clocked Serial Interface 10) – For the AD7980 part and the ST7579 LCD
Choose to generate the Transmit/receive function for the CSI10 and configure the interface with the following settings:
Transfer mode setting: Single transfer mode
Data length setting : 8 bits
Transfer direction setting:
MSB
Specification of data timing: Type 3
Transfer rate setting – Clock mode: Internal clock (master)
Transfer rate setting – Baudrate: 1000000 (bps)
Interrupt setting – Transfer interrupt priority (INTCSI10): Low
Uncheck the callback functions.
TM00 (Timer 00) – For the DelayMs() function
Configure TM00 as an interval timer:
Interval timer setting - Interval value(16 bits):
1 ms
Interval timer setting - Uncheck Generates INTM00 when counting is started
Interrupt setting - Uncheck End of timer channel 0 count, generate an interrupt (INTM00)
Watchdog Timer
Disable the watchdog timer:
Reference Project Overview
The reference project initiates conversions and reads the captured data from the AD7980.
Software Project Tutorial
This section presents the steps for developing a software application that will run on the Renesas Demo Kit for RL78G13 for controlling and monitoring the operation of the ADI part.
Two software applications have to be used: Applilet3 for RL78G13 (a tool that automatically generates device drivers for MCU peripheral functions) and IAR Embedded Workbench for Renesas RL78 (the integrated development environment).
Step 1 - Applilet3 for RL78G13
Now the desired peripherals can be configured and the code can be generated. For example, if the clocked serial interface 10 (CSI10) has to be configured, select the Serial peripheral, choose for the Channel 2 of Serial Array Unit 0 (SAU0) the CSI10 interface, Transmit/receive function option and then go to CSI10 tab.
To configure the
CSI10 interface for serial transmissions of 8 bits, with
MSB first, with the data captured on clock's rising edge, with a frequency of the clock of 1
MHz and the idle state high, the settings from the following image have to be made.
Step 2 - IAR Embedded Workbench for Renesas RL78
Renesas RX62N Quick Start Guide
This section contains a description of the steps required to run the AD7980 demonstration project on a Renesas RX62N platform.
Required Hardware
Required Software
Hardware Setup
A PmodAD4 has to be interfaced with the Renesas Demonstration Kit (RDK) for RX62N:
PmodAD4 Pin 1 (CS) → YRDKRX62N J8 connector Pin 15
PmodAD4 Pin 2 (MOSI) → YRDKRX62N J8 connector Pin 19
PmodAD4 Pin 3 (MISO) → YRDKRX62N J8 connector Pin 22
PmodAD4 Pin 4 (CLK) → YRDKRX62N J8 connector Pin 20
PmodAD4 Pin 5 (GND) → YRDKRX62N J8 connector Pin 4
PmodAD4 Pin 6 (VCC) → YRDKRX62N J8 connector Pin 3
Reference Project Overview
The reference project initiates conversions and reads the captured data from the AD7980.
Software Project Setup
This section presents the steps for developing a software application that will run on the Renesas Demo Kit for RX62N for controlling and monitoring the operation of the ADI part.
Run the High-performance Embedded Workshop integrated development environment.
A window will appear asking to create or open project workspace. Choose “Create a new project workspace” option and press OK.
From “Project Types” option select “Application”, name the Workspace and the Project “ADIEvalBoard”, select the “RX” CPU family and “Renesas RX Standard” tool chain. Press OK.
The RPDL (Renesas Peripheral Driver Library) has to integrated in the project. Unzip the RPDL files (double-click on the file “RPDL_RX62N.exe”). Navigate to where the RPDL files were unpacked and double-click on the “Copy_RPDL_RX62N.bat” to start the copy process. Choose the LQFP package, type the full path where the project was created and after the files were copied, press any key to close the window.
The new source files have to be included in the project. Use the key sequence Alt, P, A to open the “Add files to project ‘ADIEvalBoard’” window. Double click on the RPDL folder. From the “Files of type” drop-down list, select “C source file (*.C)”. Select all of the files and press Add.
To avoid conflicts with standard project files remove the files “intprg.c” and “vecttbl.c” which are included in the project. Use the key sequence Alt, P, R to open the “Remove Project Files” window. Select the files, click on Remove and press OK.
Next the new directory has to be included in the project. Use the key sequence Alt, B, R to open the “RX Standard Toolchain” window. Select the C/C++ tab, select “Show entries for: Include file directories” and press Add. Select “Relative to: Project directory”, type “RPDL” as sub-directory and press OK.
The library file path has to be added in the project. Select the Link/Library tab, select “Show entries for: Library files” and press Add. Select “Relative to: Project directory”, type “RPDL\RX62N_library” as file path and press OK.
Because the “intprg.c” file was removed the “PIntPrg” specified in option “start” has to be removed. Change “Category” to “Section”. Press “Edit”, select “PIntPRG” and press “Remove”. From this window the address of each section can be also modified. After all the changes are made press OK two times.
Now, the files have to be included in the project. Use the key sequence
Alt, P, A to open the “
Add files to project ‘ADIEvalBoard’” window. Navigate into
ADI folder. From the “
Files of type” drop-down list, select “
Project Files”. Select all the copied files and press
Add.
Now, the project is ready to be built. Press F7. The message after the Build Process is finished has to be “0 Errors, 0 Warnings”. To run the program on the board, you have to download the firmware into the microprocessor’s memory.
Digilent Cerebot MX3cK Quick Start Guide
This section contains a description of the steps required to run the AD7980 demonstration project on a Digilent Cerebot MX3cK platform.
Required Hardware
Required Software
Hardware Setup
A PmodAD4 has to be connected to the JE connector of Cerebot MX3cK development board.
Reference Project Overview
Following commands were implemented in this version of AD7980 reference project for Cerebot MX3cK board.
Command | Description |
help? | Displays all available commands. |
voltage? | Initiates a conversion and displays the captured voltage. |
register? | Initiates a conversion and displays the raw data in decimal format. |
Commands can be executed using a serial terminal connected to the UART1 peripheral of PIC32MX320F128H.
The following image shows a list of commands in a serial terminal connected to processor’s UART peripheral.
Software Project Setup
This section presents the steps for developing a software application that will run on the Digilent Cerebot MX3cK development board for controlling and monitoring the operation of the ADI part.
Run the MPLAB X integrated development environment.
Choose to create a new project.
In the Choose Project window select Microchip Embedded category, Standalone Project and press Next.
Digilent Cerebot MC7 Quick Start Guide
This section contains a description of the steps required to run the AD7980 demonstration project on a Digilent Cerebot MC7 platform.
Required Hardware
Required Software
Hardware Setup
A PmodAD4 has to be connected to the JB connector of Cerebot MC7 development board.
Reference Project Overview
Following commands were implemented in this version of AD7980 reference project for Cerebot MC7 board.
Command | Description |
help? | Displays all available commands. |
voltage? | Initiates a conversion and displays the captured voltage. |
register? | Initiates a conversion and displays the raw data in decimal format. |
Commands can be executed using a serial terminal connected to the UART1 peripheral of dsPIC33FJ128MC706A.
The following image shows a list of commands in a serial terminal connected to processor’s UART peripheral.
Software Project Setup
This section presents the steps for developing a software application that will run on the Digilent Cerebot MC7 development board for controlling and monitoring the operation of the ADI part.
Run the MPLAB X integrated development environment.
Choose to create a new project.
In the Choose Project window select Microchip Embedded category, Standalone Project and press Next.
Digilent Cerebot MX3cK Quick Start Guide - Arduino
This section contains a description of the steps required to run the AD7980 Arduino demonstration project on a Digilent Cerebot MX3cK platform.
Required Hardware
Required Software
Hardware Setup
A PmodAD4 has to be connected to the JE connector of Cerebot MX3cK development board.
Reference Project Overview
Following commands were implemented in this version of AD7980 Arduino reference project for Cerebot MX3cK board.
Command | Description |
help? | Displays all available commands. |
voltage? | Initiates a conversion and displays the captured voltage. |
register? | Initiates a conversion and displays the raw data in decimal format. |
Commands can be executed using the serial monitor.
Carriage return has to be selected as a line ending character. The required baud rate is 9600 baud.
The following image shows a list of commands in the serial monitor.
Software Project Setup
This section presents the steps for developing a chipKIT application that will run on the Digilent Cerebot MX3cK development board for controlling and monitoring the operation of the ADI part.
Under your Sketchbook directory create a folder called “Libraries”; this folder may already exist.
Unzip the downloaded file in the libraries folder.
Run the MPIDE environment.
You should see the new library under Sketch→Import Library, under Contributed.
Select the Cerebot MX3cK board from Tools→Board.
Select the corresponding Serial Communication Port from Tools→Serial Port
The project is ready to be uploaded on the development board.