adc.h

Develop Zigbee network real-time Os

/*
 * Copyright (c) 2007 University of Copenhagen
 * All rights reserved.
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 * modification, are permitted provided that the following conditions
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 * - Redistributions in binary form must reproduce the above copyright
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 *   from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
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 */

/******************************************************************************
*******************             ADC macros/functions        *******************
*******************************************************************************

These functions/macros simplifies usage of the ADC.

******************************************************************************/
// Macro for setting up a single conversion. If ADCCON1.STSEL = 11, using this
// macro will also start the conversion.
#define ADC_SINGLE_CONVERSION(settings) \
   do{ ADCCON3 = settings; }while(0)

// Macro for setting up a single conversion
#define ADC_SEQUENCE_SETUP(settings) \
   do{ ADCCON2 = settings; }while(0)

// Where _settings_ are the following:
// Reference voltage:
#define ADC_REF_1_25_V      0x00     // Internal 1.25V reference
#define ADC_REF_P0_7        0x40     // External reference on AIN7 pin
#define ADC_REF_AVDD        0x80     // AVDD_SOC pin
#define ADC_REF_P0_6_P0_7   0xC0     // External reference on AIN6-AIN7 differential input

// Resolution (decimation rate):
#define ADC_8_BIT           0x00     //  64 decimation rate
#define ADC_10_BIT          0x10     // 128 decimation rate
#define ADC_12_BIT          0x20     // 256 decimation rate
#define ADC_14_BIT          0x30     // 512 decimation rate
// Input channel:
#define ADC_AIN0            0x00     // single ended P0_0
#define ADC_AIN1            0x01     // single ended P0_1
#define ADC_AIN2            0x02     // single ended P0_2
#define ADC_AIN3            0x03     // single ended P0_3
#define ADC_AIN4            0x04     // single ended P0_4
#define ADC_AIN5            0x05     // single ended P0_5
#define ADC_AIN6            0x06     // single ended P0_6
#define ADC_AIN7            0x07     // single ended P0_7

#define ADC_AIN0_AIN1       0x08     // differential input P0_0-P0_1
#define ADC_AIN2_AIN3       0x09     // differential input P0_2-P0_3
#define ADC_AIN4_AIN5       0x0A     // differential input P0_4-P0_5
#define ADC_AIN6_AIN7       0x0B     // differential input P0_6-P0_7

#define ADC_GND             0x0C     // Ground
#define ADC_PVR             0x0D     // Positive voltage reference
#define ADC_TEMP_SENS       0x0E     // on-chip temperature sensor
#define ADC_VDD_3           0x0F     // (vdd/3)


//-----------------------------------------------------------------------------
// Macro for starting the ADC in continuous conversion mode
#define ADC_SAMPLE_CONTINUOUS() \
   do { ADCCON1 &= ~0x30; ADCCON1 |= 0x10; } while (0)

// Macro for stopping the ADC in continuous mode (and setting the ADC to be
// started manually by ADC_SAMPLE_SINGLE() )
#define ADC_STOP() \
  do { ADCCON1 |= 0x30; } while (0)

// Macro for initiating a single sample in single-conversion mode (ADCCON1.STSEL = 11).
#define ADC_SAMPLE_SINGLE() \
  do { ADC_STOP(); ADCCON1 |= 0x40;  } while (0)

// Macro for configuring the ADC to be started from T1 channel 0. (T1 ch 0 must be in compare mode!!)
#define ADC_TRIGGER_FROM_TIMER1()  do { ADC_STOP(); ADCCON1 &= ~0x10;  } while (0)

// Expression indicating whether a conversion is finished or not.
#define ADC_SAMPLE_READY()  (ADCCON1 & 0x80)

// Macro for setting/clearing a channel as input of the ADC
#define ADC_ENABLE_CHANNEL(ch)   ADCCFG |=  (0x01<<ch)
#define ADC_DISABLE_CHANNEL(ch)  ADCCFG &= ~(0x01<<ch)