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AD7193-適用于單片機平臺的無操作系統驅動程序

2512826 2021-05-22 | pdf | 1.88MB | 次下載 | 10積分

資料介紹

This version (22 Jul 2019 11:22) was approved by Andrei Drimbarean.The Previously approved version (24 Jul 2013 10:04) is available.

AD7193 - No-OS Driver for Microchip Microcontroller Platforms

Supported Devices

AD7193

Evaluation Boards

PmodAD5

Overview

The AD7193 is a low noise, complete analog front end for high precision measurement applications. It contains a low noise, 24-bit sigma-delta (Σ-Δ) analog-to-digital converter (ADC). The on-chip low noise gain stage means that signals of small amplitude can interface directly to the ADC.

The device can be configured to have four differential inputs or eight pseudo differential inputs. The on-chip channel sequencer allows several channels to be enabled simultaneously, and the AD7193 sequentially converts on each enabled channel, simplifying communication with the part. The on-chip 4.92 MHz clock can be used as the clock source to the ADC or, alternatively, an external clock or crystal can be used. The output data rate from the part can be varied from 4.7 Hz to 4.8 kHz.

The device has a very flexible digital filter, including a fast settling option. Variables such as output data rate and settling time are dependent on the option selected. The AD7193 also includes a zero latency option.

The part operates with a power supply from 3 V to 5.25 V. It consumes a current of 4.65 mA, and it is available in a 28-lead TSSOP package and a 32-lead LFCSP package.

Applications

PLC/DCS analog input modules
Data acquisition
Strain gage transducers
Pressure measurement
Temperature measurement
Flow measurement
Weigh scales
Chromatography
Medical and scientific instrumentation

01 Oct 2012 10:31 · Dragos Bogdan

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 different microcontroller platforms.

Driver Description

The driver contains two parts:

The driver for the AD7193 part, which may be used, without modifications, with any microcontroller.
The Communication Driver, where the specific communication functions for the desired type of processor and communication protocol have to be implemented. This driver implements the communication with the device and hides the actual details of the communication protocol to the ADI driver.

The Communication Driver has a standard interface, so the AD7193 driver can be used exactly as it is provided.

There are three functions which are called by the AD7193 driver:

SPI_Init() – initializes the communication peripheral.
SPI_Write() – writes data to the device.
SPI_Read() – reads data from the device.

SPI driver architecture

The following functions are implemented in this version of AD7193 driver:

Function	Description
char AD7193_Init(void)	Checks if the AD7139 part is present.
void AD7193_SetRegisterValue(unsigned char registerAddress, unsigned long registerValue, unsigned char bytesNumber, unsigned char modifyCS)	Writes data into a register.
unsigned long AD7193_GetRegisterValue(unsigned char registerAddress, unsigned char bytesNumber, unsigned char modifyCS)	Reads the value of a register.
void AD7193_Reset(void)	Resets the device.
void AD7193_SetPower(unsigned char pwrMode)	Set device to idle or power-down.
void AD7193_WaitRdyGoLow(void)	Waits for RDY pin to go low.
void AD7193_ChannelSelect(unsigned short channel)	Selects the channel to be enabled.
void AD7193_Calibrate(unsigned char mode, unsigned char channel)	Performs the given calibration to the specified channel.
void AD7193_RangeSetup(unsigned char polarity, unsigned char range)	Selects the polarity of the conversion and the ADC input range.
unsigned long AD7193_SingleConversion(void)	Returns the result of a single conversion.
unsigned long AD7193_ContinuousReadAvg(unsigned char sampleNumber)	Returns the average of several conversion results.
float AD7193_TemperatureRead(void)	Read data from temperature sensor and converts it to Celsius degrees.
float AD7193_ConvertToVolts(unsigned long rawData, float vRef)	Converts 24-bit raw data to volts.

01 Oct 2012 15:09 · Dragos Bogdan

HW Platform(s):

Digilent Cerebot MX3cK (Digilent)
Cerebot MC7 (Digilent)

Downloads

AD7193 DSPIC33 Driver
AD7193 chipKIT Driver
AD7193 Driver: https://github.com/analogdevicesinc/no-OS/tree/master/drivers/adc/ad7193
PmodAD5 Demo for PIC32MX320F128H: https://github.com/analogdevicesinc/no-OS/tree/master/Microchip/PIC32MX320F128H/PmodAD5
PIC32MX320F128H Common Drivers: https://github.com/analogdevicesinc/no-OS/tree/master/Microchip/PIC32MX320F128H/Common

Digilent Cerebot MX3cK Quick Start Guide

This section contains a description of the steps required to run the AD7193 demonstration project on a Digilent Cerebot MX3cK platform.

Required Software

MPLAB X Integrated Development Environment
MPLAB XC32 compiler
The AD7193 demonstration project for PIC32MX320F128H.

The AD7193 demonstration project for PIC32MX320F128H consists of three parts: the AD7193 Driver, the PmodAD5 Demo for PIC32MX320F128H and the PIC32MX320F128H Common Drivers.

All three parts have to be downloaded.

Hardware Setup

A PmodAD5 has to be connected to the JE connector of Cerebot MX3cK development board.

When using AVDD > DVDD (= 3.3V), JP1 on PmodAD5 must be removed. The range for AVDD is 3.0V ≤ AVDD ≤ 5.25V

Reference Project Overview

The following commands were implemented in this version of AD7193 reference project for Cerebot MX3cK board.

Command	Description
help?	Displays all available commands.
reset!	Resets the AD7193.
polarity?	Displays the polarity value.
polarity=	Sets the polarity value. Accepted values: 0 - Bipolar mode. 1 - Unipolar mode.
range?	Displays the range value.
range=	Sets the range value. Accepted values: 0 - Gain=1. (Input voltage range must be +/-2500mV) 3 - Gain=8. (Input voltage range must be +/-312.5mV) 4 - Gain=16. (Input voltage range must be +/-156.2mV) 5 - Gain=32. (Input voltage range must be +/-78.12mV) 6 - Gain=64. (Input voltage range must be +/-39.06mV) 7 - Gain=128.(Input voltage range must be +/-19.53mV)
pseudoBit?	Displays the Pseudo Bit value (AD7193_REG_CONF).
pseudoBit=	Sets the Pseudo Bit Value (AD7193_REG_CONF). Accepted values: 0 - Disables the pseudo differential measuring. 1 - Enables the pseudo differential measuring.
register?	Displays the value of the data register (AD7193_REG_DATA) for specified channel. Accepted values: 0..7 - selected channel.
voltage?	Displays the voltage applied to specified channel. Accepted values: 0..7 - selected channel.
temperature?	Displays the temperature.

Commands can be executed using a serial terminal connected to the UART1 peripheral of PIC32MX320F128H.

The following image shows a generic 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.

In the Select Device window choose PIC32MX320F128H device and press Next.

In the Select Tool window select the desired hardware tool and press Next.

In the Select Compiler window chose the XC32 compiler and press Next.

In the Select Project Name and Folder window choose a name and a location for the project.

After the project is created, all the downloaded source files have to be copied in the project folder and included in the project.

The project is ready to be built and downloaded on the development board.

05 Jul 2012 14:45