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This version (24 Jul 2013 08:49) was approved by Dragos Bogdan.The Previously approved version (09 Oct 2012 09:14) is available.

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AD7303 - No-OS Driver for Microchip Microcontroller Platforms

Supported Devices

AD7303

Evaluation Boards

PmodDA1

Overview

The AD7303 is a dual, 8-bit voltage out DAC that operates from a single +2.7 V to +5.5 V supply. Its on-chip precision output buffers allow the DAC outputs to swing rail to rail. This device uses a versatile 3-wire serial interface that operates at clock rates up to 30 MHz, and is compatible with QSPI, SPI, microwire and digital signal processor interface standards. The serial input register is sixteen bits wide; 8 bits act as data bits for the DACs, and the remaining eight bits make up a control register.

The on-chip control register is used to address the relevant DAC, to power down the complete device or an individual DAC, to select internal or external reference and to provide a synchronous loading facility for simultaneous update of the DAC outputs with a software LDAC function.

The low power consumption of this part makes it ideally suited to portable battery operated equipment. The power consumption is 7.5 mW max at 3 V, reducing to less than 3 µW in full power-down mode.

The AD7303 is available in an 8-pin plastic dual in-line package, 8-lead SOIC and microSOIC packages.

28 Sep 2012 16:05 · 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 AD7303 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 AD7303 driver can be used exactly as it is provided.

There are three functions which are called by the AD7303 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 AD7303 driver:

Function	Description
char AD7303_Init(void)	Initializes the SPI communication peripheral.
void AD7303_Write(unsigned char controlReg, unsigned char dataReg)	Sends data to AD7303.

01 Oct 2012 15:11 · Dragos Bogdan

HW Platform(s):

Downloads

AD7303 DSPIC33 Driver
AD7303 chipKIT Driver
AD7303 Driver: https://github.com/analogdevicesinc/no-OS/tree/master/drivers/AD7303
PmodDA1 Demo for PIC32MX320F128H: https://github.com/analogdevicesinc/no-OS/tree/master/Microchip/PIC32MX320F128H/PmodDA1
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 AD7303 demonstration project on a Digilent Cerebot MX3cK platform.

Required Hardware

Required Software

MPLAB X Integrated Development Environment
MPLAB XC32 compiler
The AD7303 demonstration project for PIC32MX320F128H.

The AD7303 demonstration project for PIC32MX320F128H consists of three parts: the AD7303 Driver, the PmodDA1 Demo for PIC32MX320F128H and the PIC32MX320F128H Common Drivers.

All three parts have to be downloaded.

Hardware Setup

A PmodDA1 has to be connected to the JE connector of Cerebot MX3cK development board.

Reference Project Overview

The following commands were implemented in this version of AD7303 reference project for Cerebot MX3cK board.

Command	Description
help?	Displays all available commands.
power=	Powers off/on the selected channel. Accepted values: channel: 0 - Select channel A1. 1 - Select channel B1. power status: 0 - Power off. 1 - Power on.
power?	Displays the power status of the selected channel. Accepted values: 0 - Select channel A1. 1 - Select channel B1.
voltage=	Sets the output voltage of the selected channel. Accepted values: channel: 0 - Select channel A1. 1 - Select channel B1. output voltage: 0..3300 - Desired output voltage in milivolts.
voltage?	Displays last written voltage value to the DAC for selected channel. Accepted values: 0 - Select channel A1. 1 - Select channel B1.
register=	Writes to the DAC register of the selected channel. Accepted values: 0 - Select channel A1. 1 - Select channel B1. register value: 0..255 - Value written to the DAC.
register?	Displays last written value in the DAC register for selected channel. Accepted values: 0 - Select channel A1. 1 - Select channel B1.

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