adc_driver.c File Reference

XMEGA ADC driver source file. More...

#include "adc_driver.h"

Go to the source code of this file.

Functions
void	ADC_CalibrationValues_Load (ADC_t *adc)
	This function get the calibration data from the production calibration.
uint16_t	ADC_ResultCh_GetWord_Unsigned (ADC_CH_t *adc_ch, uint16_t offset)
	This function clears the interrupt flag and returns the unsigned coversion result.
int16_t	ADC_ResultCh_GetWord_Signed (ADC_CH_t *adc_ch, int16_t signedOffset)
	This function clears the interrupt flag and returns the signed coversion result.
uint16_t	ADC_ResultCh_GetWord (ADC_CH_t *adc_ch)
	This function clears the interrupt flag and returns the coversion result without compensating for offset.
uint8_t	ADC_ResultCh_GetLowByte (ADC_CH_t *adc_ch)
	This function clears the interrupt flag and returns the low byte of the coversion result.
uint8_t	ADC_ResultCh_GetHighByte (ADC_CH_t *adc_ch)
	This function clears the interrupt flag and returns the high byte of the coversion result.
void	ADC_Wait_8MHz (ADC_t *adc)
	This function waits until the adc common mode is settled.
void	ADC_Wait_32MHz (ADC_t *adc)
	This function waits until the adc common mode is settled.
uint16_t	ADC_Offset_Get_Unsigned (ADC_t *adc, ADC_CH_t *ch, bool oversampling)
	This function gets the offset of the ADC when it is configured in unsigned mode.
int16_t	ADC_Offset_Get_Signed (ADC_t *adc, ADC_CH_t *ch, bool oversampling)
	This function gets the offset of the ADC when it is configured in signed mode.

Detailed Description

XMEGA ADC driver source file.

 This file contains the function implementations the XMEGA ADC driver.

 The driver is not intended for size and/or speed critical code, since
 most functions are just a few lines of code, and the function call
 overhead would decrease code performance. The driver is intended for
 rapid prototyping and documentation purposes for getting started with
 the XMEGA ADC module.

 For size and/or speed critical code, it is recommended to copy the
 function contents directly into your application instead of making
 a function call.

 Several functions use the following construct:
     "some_register = ... | (some_parameter ? SOME_BIT_bm : 0) | ..."
 Although the use of the ternary operator ( if ? then : else ) is discouraged,
 in some occasions the operator makes it possible to write pretty clean and
 neat code. In this driver, the construct is used to set or not set a
 configuration bit based on a boolean input parameter, such as
 the "some_parameter" in the example above.

Application note:

AVR1300: Using the XMEGA ADC

Documentation

For comprehensive code documentation, supported compilers, compiler settings and supported devices see readme.html

Author

Atmel Corporation: http://www.atmel.com
Support email: avr@a.nosp@m.tmel.nosp@m..com

Revision:

2793

Date:

2009-09-21 11:12:00 +0200 (ma, 21 sep 2009)

Copyright (c) 2008, Atmel Corporation All rights reserved.

Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:

1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.

1. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.

1. The name of ATMEL may not be used to endorse or promote products derived from this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE EXPRESSLY AND SPECIFICALLY DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

Definition in file adc_driver.c.

Function Documentation

void ADC_CalibrationValues_Load

(

ADC_t *

adc

)

This function get the calibration data from the production calibration.

The calibration data is loaded from flash and stored in the calibration register. The calibration data reduces the non-linearity error in the adc.

Parameters

adc	Pointer to ADC module register section.

Definition at line 77 of file adc_driver.c.

int16_t ADC_Offset_Get_Signed	(	ADC_t *	adc,
		ADC_CH_t *	ch,
		bool	oversampling
	)

This function gets the offset of the ADC when it is configured in signed mode.

This function does one or several measurements to determine the offset of the ADC.

Note

The ADC must be configured and enabled before this function is run.

This function only return the low byte of the 12-bit convertion, because the offset should never be more than +-8 LSB off.

Parameters

adc	Pointer to the ADC to calculate offset from.
ch	Pointer to the ADC channel to measure on.
oversampling	false for one measurement. true for averaging several measurements.

Returns

Offset on the selected ADC

Definition at line 320 of file adc_driver.c.

uint16_t ADC_Offset_Get_Unsigned	(	ADC_t *	adc,
		ADC_CH_t *	ch,
		bool	oversampling
	)

This function gets the offset of the ADC when it is configured in unsigned mode.

This function does one or several measurements to determine the offset of the ADC.

Note

The ADC must be configured and enabled before this function is run.

This function only return the low byte of the 12-bit convertion, because the offset should never be more than +-8 LSB off.

Parameters

adc	Pointer to the ADC to calculate offset from.
ch	Pointer to the ADC channel to measure on.
oversampling	false for one measurement. true for averaging several measurements.

Returns

Offset on the selected ADC

Definition at line 273 of file adc_driver.c.

uint8_t ADC_ResultCh_GetHighByte

(

ADC_CH_t *

adc_ch

)

This function clears the interrupt flag and returns the high byte of the coversion result.

 This funtion should be used together with the ADC_ResultCh_ConversionComplete.
When the conversion result is ready this function reads out the result.

Note

If this function is used with 12-bit right adjusted results, it returns the 8 LSB only. Offset is not compensated.

Parameters

adc_ch

Pointer to ADC channel register section.

Returns

High byte of conversion result.

Definition at line 188 of file adc_driver.c.

uint8_t ADC_ResultCh_GetLowByte

(

ADC_CH_t *

adc_ch

)

This function clears the interrupt flag and returns the low byte of the coversion result.

 This funtion should be used together with the ADC_Ch_Conversion_Complete.
When the conversion result is ready this funciton reads out the result.

Note

If this function is used with 12-bit right adjusted results, it returns the 8 LSB only. Offset is not compensated.

Parameters

adc_ch

Pointer to ADC channel register section.

Returns

Low byte of conversion result.

Definition at line 168 of file adc_driver.c.

uint16_t ADC_ResultCh_GetWord

(

ADC_CH_t *

adc_ch

)

This function clears the interrupt flag and returns the coversion result without compensating for offset.

 This function should be used together with the ADC_Ch_Conversion_Complete.
When the conversion result is ready this funciton reads out the result.

Parameters

adc_ch

Pointer to ADC channel register section.

Returns

Signed conversion result.

Definition at line 146 of file adc_driver.c.

int16_t ADC_ResultCh_GetWord_Signed	(	ADC_CH_t *	adc_ch,
		int16_t	signedOffset
	)

This function clears the interrupt flag and returns the signed coversion result.

 This function should be used together with the ADC_Ch_Conversion_Complete.
When the conversion result is ready this funciton reads out the result.

Parameters

adc_ch	Pointer to ADC channel register section.
signedOffset	Offset value to subtract.

Returns

The signed Conversion result with the offset substracted.

Definition at line 125 of file adc_driver.c.

uint16_t ADC_ResultCh_GetWord_Unsigned	(	ADC_CH_t *	adc_ch,
		uint16_t	offset
	)

This function clears the interrupt flag and returns the unsigned coversion result.

 This function should be used together with the ADC_Ch_Conversion_Complete.
When the conversion result is ready this funciton reads out the result.

Parameters

adc_ch	Pointer to ADC channel register section.
offset	Unsigned offset value to subtract.

Returns

The unsigned Conversion result with the offset substracted.

Definition at line 102 of file adc_driver.c.

void ADC_Wait_32MHz

(

ADC_t *

adc

)

This function waits until the adc common mode is settled.

After the ADC clock has been turned on, the common mode voltage in the ADC need some time to settle. The time it takes equals one dummy conversion. Instead of doing a dummy conversion this function waits until the common mode is settled.

Note

The function sets the prescaler to the minimum value possible when the clock speed is larger than 8 MHz to minimize the time it takes the common mode to settle.

The ADC clock is turned off every time the ADC i disabled or the device goes into sleep (not Idle sleep mode).

Parameters

adc	Pointer to ADC module register section.

Definition at line 242 of file adc_driver.c.

void ADC_Wait_8MHz

(

ADC_t *

adc

)

This function waits until the adc common mode is settled.

After the ADC clock has been turned on, the common mode voltage in the ADC need some time to settle. The time it takes equals one dummy conversion. Instead of doing a dummy conversion this function waits until the common mode is settled.

Note

The function sets the prescaler to the minimum value to minimize the time it takes the common mode to settle. If the clock speed is higher than 8 MHz use the ADC_wait_32MHz function.

Parameters

adc	Pointer to ADC module register section.

Definition at line 210 of file adc_driver.c.