mirror of
https://github.com/arduino/Arduino.git
synced 2024-11-30 11:24:12 +01:00
94 lines
2.5 KiB
C
Executable File
94 lines
2.5 KiB
C
Executable File
/*! \file ads7828.c \brief TI ADS7828 12-bit 8ch A/D Converter Driver Library. */
|
|
//*****************************************************************************
|
|
//
|
|
// File Name : 'ads7828.c'
|
|
// Title : TI ADS7828 12-bit 8ch A/D Converter Driver Library
|
|
// Author : Pascal Stang - Copyright (C) 2004
|
|
// Created : 2004.02.10
|
|
// Revised : 2004.02.19
|
|
// Version : 0.1
|
|
// Target MCU : Atmel AVR Series
|
|
// Editor Tabs : 4
|
|
//
|
|
// NOTE: This code is currently below version 1.0, and therefore is considered
|
|
// to be lacking in some functionality or documentation, or may not be fully
|
|
// tested. Nonetheless, you can expect most functions to work.
|
|
//
|
|
// This code is distributed under the GNU Public License
|
|
// which can be found at http://www.gnu.org/licenses/gpl.txt
|
|
//
|
|
//*****************************************************************************
|
|
|
|
#include <avr/io.h>
|
|
#include <avr/signal.h>
|
|
#include <avr/interrupt.h>
|
|
|
|
#include "global.h"
|
|
#include "i2c.h"
|
|
#include "ads7828.h"
|
|
|
|
// global variables
|
|
u08 Ads7282RefMode;
|
|
|
|
// Functions
|
|
u08 ads7828Init(u08 i2cAddr)
|
|
{
|
|
u08 channel = 0x80;
|
|
|
|
// setup default A/D voltage reference
|
|
ads7828SetReference(0);
|
|
|
|
// issue a convserion to test chip presence
|
|
// return TRUE if chip detected
|
|
// return FALSE if chip does not respond
|
|
return (i2cMasterSendNI(i2cAddr, 1, &channel) == I2C_OK);
|
|
}
|
|
|
|
u16 ads7828Convert(u08 i2cAddr, u08 channel)
|
|
{
|
|
// re-order channel bits for
|
|
// logical single-ended channel selection
|
|
// channel bit0 -> C2
|
|
// channel bit1 -> C0
|
|
// channel bit2 -> C1
|
|
channel = (((channel>>1) | (channel&0x01)<<2)<<4) | ADS7828_CMD_SD;
|
|
// do conversion
|
|
return ads7828ConvertRaw(i2cAddr, channel);
|
|
}
|
|
|
|
u16 ads7828ConvertDiff(u08 i2cAddr, u08 channel)
|
|
{
|
|
// clear single-ended channel bit
|
|
channel = (channel&0x07)<<4;
|
|
// do conversion
|
|
return ads7828ConvertRaw(i2cAddr, channel);
|
|
}
|
|
|
|
u16 ads7828ConvertRaw(u08 i2cAddr, u08 channel)
|
|
{
|
|
u08 buffer[2];
|
|
// combine raw channel and reference bits
|
|
channel &= 0xF0;
|
|
channel |= Ads7282RefMode;
|
|
// start conversion on requested channel
|
|
i2cMasterSendNI(i2cAddr, 1, &channel);
|
|
// retrieve conversion result
|
|
i2cMasterReceiveNI(i2cAddr, 2, buffer);
|
|
// pack bytes and return result
|
|
return ((buffer[0]<<8) | buffer[1]);
|
|
}
|
|
|
|
void ads7828SetReference(u08 ref)
|
|
{
|
|
if(ref)
|
|
{
|
|
// use internal reference
|
|
Ads7282RefMode = ADS7828_CMD_PDMODE2;
|
|
}
|
|
else
|
|
{
|
|
// use external reference
|
|
Ads7282RefMode = ADS7828_CMD_PDMODE0;
|
|
}
|
|
}
|