Detailed Description

Analog to Digital Conversion (ADC) Input Driver.

Overview

The ADC driver allows you to manage an Analog to Digital peripheral via simple and portable APIs. This driver supports sampling and converting raw values into microvolts.

Usage

This documentation provides a basic usage summary and a set of examples in the form of commented code fragments. Detailed descriptions of the APIs are provided in subsequent sections.

Synopsis

// Import ADC Driver definitions
#include <ti/drivers/ADC.h>
// Define name for ADC channel index
#define THERMOCOUPLE_OUT  0
// One-time init of ADC driver
ADC_init();
// initialize optional ADC parameters
ADC_Params params;
ADC_Params_init(&params);
params.isProtected = true;
// Open ADC channels for usage
ADC_Handle adcHandle = ADC_open(THERMOCOUPLE_OUT, &params);
// Sample the analog output from the Thermocouple
ADC_convert(adcHandle, &result);
// Convert the sample to microvolts
resultUv = ADC_convertToMicroVolts(adcHandle, result);
ADC_close(adcHandle);

Examples

Opening an ADC instance

ADC_Handle adc;
ADC_Params params;
ADC_Params_init(&params);
adc = ADC_open(0, &params);
if (adc == NULL) {
    // ADC_open() failed
    while (1) {}
}

Taking an ADC sample

An ADC conversion with an ADC peripheral is started by calling ADC_convert(). The result value is returned by ADC_convert() once the conversion is finished.

int_fast16_t res;
uint_fast16_t adcValue;
res = ADC_convert(adc, &adcValue);
if (res == ADC_STATUS_SUCCESS)
{
    print(adcValue);
}

Converting a sample to microvolts

The result value returned by ADC_convert() is a raw value. The following uses ADC_convertToMicroVolts() to convert the raw value into microvolts.

int_fast16_t res;
uint_fast16_t adcValue;
uint32_t adcValueUv;
res = ADC_convert(adc, &adcValue);
if (res == ADC_STATUS_SUCCESS)
{
    adcValueUv = ADC_convertToMicroVolts(adc, adcValue);
}

Configuration

Refer to the Driver's Configuration section for driver configuration information.

#include <stdbool.h>
#include <stdint.h>

Include dependency graph for ADC.h:

This graph shows which files directly or indirectly include this file:

Go to the source code of this file.

Data Structures
struct	ADC_Params
	ADC Parameters used with ADC_open(). More...

struct	ADC_FxnTable
	The definition of an ADC function table that contains the required set of functions to control a specific ADC driver implementation. More...

struct	ADC_Config
	ADC driver's custom configuration structure. More...

Macros
#define	ADC_convertRawToMicroVolts ADC_convertToMicroVolts

#define	ADC_CMD_RESERVED

#define	ADC_STATUS_RESERVED


#define	ADC_STATUS_SUCCESS (0)
	Successful status code returned by ADC_control(). More...

#define	ADC_STATUS_ERROR (-1)
	Generic error status code returned by ADC_control(). More...

#define	ADC_STATUS_UNDEFINEDCMD (-2)
	An error status code returned by ADC_control() for undefined command codes. More...

Typedefs
typedef struct ADC_Config *	ADC_Handle
	A handle that is returned from an ADC_open() call. More...

typedef struct ADC_Config	ADC_Config
	ADC driver's custom configuration structure. More...

Functions
void	ADC_close (ADC_Handle handle)
	Function to close an ADC driver instance. More...

int_fast16_t	ADC_control (ADC_Handle handle, uint_fast16_t cmd, void *arg)
	Function performs implementation specific features on a driver instance. More...

int_fast16_t	ADC_convert (ADC_Handle handle, uint16_t *value)
	Function to perform an ADC conversion. More...

uint32_t	ADC_convertToMicroVolts (ADC_Handle handle, uint16_t adcValue)
	Function to convert a raw ADC sample into microvolts. More...

void	ADC_init (void)
	Function to initialize the ADC driver. More...

ADC_Handle	ADC_open (uint_least8_t index, ADC_Params *params)
	Function to initialize the ADC peripheral. More...

void	ADC_Params_init (ADC_Params *params)
	Initialize an ADC_Params structure to its default values. More...

Macro Definition Documentation

§ ADC_convertRawToMicroVolts

#define ADC_convertRawToMicroVolts ADC_convertToMicroVolts

Deprecated:: ADC_convertRawToMicroVolts() is succeeded by ADC_convertToMicroVolts().

Typedef Documentation

§ ADC_Handle

typedef struct ADC_Config* ADC_Handle

A handle that is returned from an ADC_open() call.

§ ADC_Config

typedef struct ADC_Config ADC_Config

ADC driver's custom configuration structure.

See also: ADC_init(); ADC_open()

Function Documentation

§ ADC_close()

void ADC_close ( ADC_Handle handle )

Function to close an ADC driver instance.

Precondition: ADC_open() has to be called first.

Parameters

[in] handle An ADC_Handle returned from ADC_open()

§ ADC_control()

int_fast16_t ADC_control	(	ADC_Handle	handle,
		uint_fast16_t	cmd,
		void *	arg
	)

Function performs implementation specific features on a driver instance.

Precondition: ADC_open() has to be called first.

Parameters

[in]	handle	An ADC_Handle returned from ADC_open()
[in]	cmd	A command value defined by the device specific implementation
[in]	arg	An optional R/W (read/write) argument that is accompanied with `cmd`

Returns: Implementation specific return codes. Negative values indicate unsuccessful operations.

Return values

ADC_STATUS_SUCCESS	The call was successful.
ADC_STATUS_UNDEFINEDCMD	The `cmd` value is not supported by the device specific implementation.

§ ADC_convert()

int_fast16_t ADC_convert	(	ADC_Handle	handle,
		uint16_t *	value
	)

Function to perform an ADC conversion.

Function to perform a single channel sample conversion.

Precondition: ADC_open() has been called

Parameters

[in]	handle	An ADC_Handle returned from ADC_open()
[in,out]	value	A pointer to a uint16_t to store the conversion result

Return values

ADC_STATUS_SUCCESS	The conversion was successful.
ADC_STATUS_ERROR	The conversion failed and `value` is invalid.

See also: ADC_convertToMicroVolts()

§ ADC_convertToMicroVolts()

uint32_t ADC_convertToMicroVolts	(	ADC_Handle	handle,
		uint16_t	adcValue
	)

Function to convert a raw ADC sample into microvolts.

Precondition: ADC_convert() has to be called first.

Parameters

[in]	handle	An ADC_Handle returned from ADC_open()
[in]	adcValue	A sampling result return from ADC_convert()

Returns: adcValue converted into microvolts

See also: ADC_convert()

§ ADC_init()

void ADC_init ( void )

Function to initialize the ADC driver.

This function must also be called before any other ADC driver APIs.

§ ADC_open()

ADC_Handle ADC_open	(	uint_least8_t	index,
		ADC_Params *	params
	)

Function to initialize the ADC peripheral.

Function to initialize the ADC peripheral specified by the particular index value.

Precondition: ADC_init() has been called

Parameters

[in]	index	Index in the `ADC_Config`[] array.
[in]	params	Pointer to an initialized ADC_Params structure. If NULL, the default ADC_Params values are used.

Returns: An ADC_Handle on success or NULL on error.

See also: ADC_init(); ADC_close()

§ ADC_Params_init()

void ADC_Params_init ( ADC_Params * params )

Initialize an ADC_Params structure to its default values.

Parameters

[in] params A pointer to an ADC_Params structure.

Default values are:

ADC_Params.custom = NULL
ADC_Params.isProtected = true

Detailed Description

Overview

Usage

Synopsis

Examples

Opening an ADC instance

Taking an ADC sample

Converting a sample to microvolts

Configuration

Data Structures

Macros

Typedefs

Functions

Macro Definition Documentation

§ ADC_convertRawToMicroVolts

Typedef Documentation

§ ADC_Handle

§ ADC_Config

Function Documentation

§ ADC_close()

§ ADC_control()

§ ADC_convert()

§ ADC_convertToMicroVolts()

§ ADC_init()

§ ADC_open()

§ ADC_Params_init()