library

/*! \file ads7870.h \brief TI ADS7870 12-bit 8ch A/D Converter Driver Library. */
//*****************************************************************************
//
// File Name    : 'ads7870.h'
// Title                : TI ADS7870 12-bit 8ch A/D Converter Driver Library
// Author               : Pascal Stang - Copyright (C) 2005
// Created              : 2005.07.19
// Revised              : 2005.07.21
// 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
//
///     \ingroup driver_hw
/// \defgroup ads7870 TI ADS7870 SPI A/D Converter Driver (ads7870.c)
/// \code #include "ads7870.h" \endcode
/// \par Overview
///             This library provides high-level functions for accessing the Texas
///             Instruments ADS7870 I2C A/D Converter.
///
///             The basic specs of the ADS7870 are:
///             - Fast SPI interface (up to 20MHz)
///             - 12-bit results
///             - 8 single-ended or 4 differential input channels
///             - Programmable gain stage (1,2,4,5,8,10,16,20x gains)
///             - Software or hardware triggered conversion
///             - 4-bit auxiliary digital I/O lines (controlled via serial interface)
///             - Up to 50KHz conversion rate
///             - External reference or internal 2.5V, 2.048V, 1.15V reference
///             - NOTE: use pin-compatible ADS7871 for 14-bit results
//
//*****************************************************************************
//@{

#ifndef ADS7870_H
#define ADS7870_H

#include "global.h"

// constants/macros/typdefs
#define ADS7870_CS_PORT                 PORTB
#define ADS7870_CS_DDR                  DDRB
#define ADS7870_CS_PIN                  PB0

// instruction bit defines
#define ADS7870_CONVERT                 0x80

#define ADS7870_REG_READ                0x40
#define ADS7870_REG_WRITE               0x00
#define ADS7870_REG_16BIT               0x20

// register addresses
#define ADS7870_RESULTLO                0x00
#define ADS7870_RESULTHI                0x01
#define ADS7870_PGAVALID                0x02
#define ADS7870_ADCTRL                  0x03
#define ADS7870_GAINMUX                 0x04
#define ADS7870_DIGIOSTATE              0x05
#define ADS7870_DIGIOCTRL               0x06
#define ADS7870_REFOSC                  0x07
#define ADS7870_SERIFCTRL               0x18
#define ADS7870_ID                              0x1F

// register bit defines
#define ADS7870_RESULTLO_OVR    0x01

#define ADS7870_ADCTRL_BIN              0x20
#define ADS7870_ADCTRL_RMB1             0x08
#define ADS7870_ADCTRL_RMB0             0x04
#define ADS7870_ADCTRL_CFD1             0x02
#define ADS7870_ADCTRL_CFD0             0x01

#define ADS7870_GAINMUX_CNVBSY  0x80

#define ADS7870_REFOSC_OSCR             0x20
#define ADS7870_REFOSC_OSCE             0x10
#define ADS7870_REFOSC_REFE             0x08
#define ADS7870_REFOSC_BUFE             0x04
#define ADS7870_REFOSC_R2V              0x02
#define ADS7870_REFOSC_RBG              0x01

#define ADS7870_SERIFCTRL_LSB   0x01
#define ADS7870_SERIFCTRL_2W3W  0x02
#define ADS7870_SERIFCTRL_8051  0x04

#define ADS7870_ID_VALUE                0x01

// gain defines
#define ADS7870_GAIN_1X                 0x00
#define ADS7870_GAIN_2X                 0x10
#define ADS7870_GAIN_4X                 0x20
#define ADS7870_GAIN_5X                 0x30
#define ADS7870_GAIN_8X                 0x40
#define ADS7870_GAIN_10X                0x50
#define ADS7870_GAIN_16X                0x60
#define ADS7870_GAIN_20X                0x70
// channel defines
#define ADS7870_CH_0_1_DIFF             0x00
#define ADS7870_CH_2_3_DIFF             0x01
#define ADS7870_CH_4_5_DIFF             0x02
#define ADS7870_CH_6_7_DIFF             0x03
#define ADS7870_CH_1_0_DIFF             0x04
#define ADS7870_CH_3_2_DIFF             0x05
#define ADS7870_CH_5_4_DIFF             0x06
#define ADS7870_CH_7_6_DIFF             0x07
#define ADS7870_CH_SINGLE_ENDED 0x08
#define ADS7870_CH_0                    0x08
#define ADS7870_CH_1                    0x09
#define ADS7870_CH_2                    0x0A
#define ADS7870_CH_3                    0x0B
#define ADS7870_CH_4                    0x0C
#define ADS7870_CH_5                    0x0D
#define ADS7870_CH_6                    0x0E
#define ADS7870_CH_7                    0x0F

// functions

//! Initialize the ADS7870 chip.
///     Returns:
///     TRUE if successful, 
///     FALSE if unsuccessful (chip not responding).
u08 ads7870Init(void);

//! Begin single-ended conversion on given logical channel#0-7, and return result.
/// \note Result is returned left-justified.
s16 ads7870Convert(u08 channel);

//! Begin differential conversion on given channel pair, and return result.
/// \note Result is returned left-justified.
s16 ads7870ConvertDiff(u08 channel);

//! Begin conversion on given raw channel#, and return result.
/// \note Result is returned left-justified.
s16 ads7870ConvertRaw(u08 channel);

//! Read value from ADS7870 register.
///
u08 ads7870ReadReg(u08 reg);

//! Write value into ADS7870 register.
///
void ads7870WriteReg(u08 reg, u08 value);



#endif
//@}