API for the ADC121C021 I2C Analog-to-Digital Converter. More...

Detailed Description

ID: adc121c021
Name: I2C 12-bit Analog to Digital Converter with Alert Pin
Other Names: Grove I2C ADC
Category: electric
Manufacturer: seeed
Link: http://www.seeedstudio.com/depot/Grove-I2C-ADC-p-1580.html
Connection: i2c

UPM module for the ADC121C021 12-bit analog-to-digital converter (ADC). By constantly providing a reference voltage, this sensor helps increase the accuracy of a value collected from an analog sensor.

    // Instantiate an ADC121C021 on I2C bus 0
    upm::ADC121C021 adc(ADC121C021_I2C_BUS, ADC121C021_DEFAULT_I2C_ADDR);
    // An analog sensor, such as a Grove light sensor,
    // must be attached to the adc
    // Prints the value and corresponding voltage every 50 milliseconds
    while (shouldRun) {
        uint16_t val = adc.value();
        cout << "ADC value: " << val << " Volts = " << adc.valueToVolts(val) << endl;
        upm_delay_us(50000);
    }

Public Member Functions
	ADC121C021 (int bus, uint8_t address=ADC121C021_DEFAULT_I2C_ADDR, float vref=ADC121C021_DEFAULT_VREF)

	~ADC121C021 ()

mraa_result_t	writeByte (uint8_t reg, uint8_t byte)

mraa_result_t	writeWord (uint8_t reg, uint16_t word)

uint8_t	readByte (uint8_t reg)

uint16_t	readWord (uint8_t reg)

uint16_t	value ()

float	valueToVolts (uint16_t val)

bool	getAlertStatus ()

bool	alertLowTriggered ()

bool	alertHighTriggered ()

void	clearAlertStatus ()

void	enableAlertFlag (bool enable)

void	enableAlertPin (bool enable)

void	enableAlertHold (bool enable)

void	enableAlertPinPolarityHigh (bool enable)

void	setAutomaticConversion (ADC121C021_CYCLE_TIME_T cycleTime)

mraa_result_t	setAlertLowLimit (uint16_t limit)

mraa_result_t	setAlertHighLimit (uint16_t limit)

mraa_result_t	setHysteresis (uint16_t limit)

uint16_t	getHighestConversion ()

uint16_t	getLowestConversion ()

mraa_result_t	clearHighestConversion ()

mraa_result_t	clearLowestConversion ()

Constructor & Destructor Documentation

ADC121C021	(	int	bus,
		uint8_t	address = `ADC121C021_DEFAULT_I2C_ADDR`,
		float	vref = `ADC121C021_DEFAULT_VREF`
	)

ADC121C021 ADC constructor

Parameters

bus	I2C bus to use
address	Address for this sensor; default is 0x55
vref	Reference voltage for this sensor; default is 3.0v

~ADC121C021 ( )

ADC121C021 destructor

Member Function Documentation

mraa_result_t writeByte	(	uint8_t	reg,
		uint8_t	byte
	)

Writes a byte value into the register

Parameters

reg	Register location to write into
byte	Byte to write

Returns: 0 (MRAA_SUCCESS) if successful; non-zero otherwise

mraa_result_t writeWord	(	uint8_t	reg,
		uint16_t	word
	)

Writes a word value into the register

Parameters

reg	Register location to write into
word	Word to write

Returns: 0 (MRAA_SUCCESS) if successful; non-zero otherwise

uint8_t readByte ( uint8_t reg )

Reads the byte value from the register

Parameters

reg	Register location to read from

Returns: Value in the specified register

uint16_t readWord ( uint8_t reg )

Reads the word value from the register

Parameters

reg	Register location to read from

Returns: Value in the specified register

uint16_t value ( )

Reads the current value of conversion

Returns: Current value of conversion

float valueToVolts ( uint16_t val )

Converts a supplied value to voltage based on the set vref

Parameters

val	Value of conversion (from value())

Returns: Value of conversion in volts

bool getAlertStatus ( )

Reads the current status of the alert flag. If the flag is set, the low or high alert indicators are set as appropriate, and you can access these values with alertLowTriggered() or alertHighTriggered().

Returns: True if the alert flag is set

bool alertLowTriggered ( )

inline

Returns the current value of m_alertLow. You must call getAlertStatus() to update this value.

Returns: Current status of the alert low flag

bool alertHighTriggered ( )

inline

Returns the current value of m_alertHigh. You must call getAlertStatus() to update this value.

Returns: Current status of the alert high flag

Here is the call graph for this function:

void clearAlertStatus ( )

Clears the alert low and alert high flags. This also clears the last stored alert values.

Here is the caller graph for this function:

void enableAlertFlag ( bool enable )

Enables or disables the alert flag functionality. If enabled, when the measured value exceeds the low or high limits configured, the alert flag is set. Use getAlertStatus() to access these values.

Parameters

enable If true, enables the alert flag; otherwise, disables the alert flag

Here is the caller graph for this function:

void enableAlertPin ( bool enable )

Enables or disables the alert pin functionality.

Parameters

enable If true, enables the alert pin; otherwise, disables the alert pin

Here is the caller graph for this function:

void enableAlertHold ( bool enable )

Enables or disables the alert hold functionality. When the alert hold is enabled, the alert status remains until manually cleared via clearAlertStatus(). Otherwise, the alert self-clears when the value moves into the defined limits if alerts are enabled via enableAlertFlag().

Parameters

enable If true, enables the alert hold; otherwise, disables the alert hold

Here is the caller graph for this function:

void enableAlertPinPolarityHigh ( bool enable )

If the alert pin is enabled, defines the active polarity of the pin in an alert condition. Enabling this sets the pin to active high in an alert condition; otherwise, active low is used.

Parameters

enable If true, the alert pin is active high; otherwise, active low

Here is the caller graph for this function:

void setAutomaticConversion ( ADC121C021_CYCLE_TIME_T cycleTime )

Enables or disables the automatic conversion mode. When enabled, the ADC samples and updates the conversion value independently. It is disabled by default, so conversion is only done by calling value().

Parameters

cycleTime Sets the cycle time for automatic conversion

Here is the caller graph for this function:

mraa_result_t setAlertLowLimit ( uint16_t limit )

Sets the alert low limit. If alerts are enabled and the measured conversion value is lower than the low limit, an alert is triggered.

Parameters

limit Alert low limit

Returns: 0 (MRAA_SUCCESS) if successful; non-zero otherwise

Here is the caller graph for this function:

mraa_result_t setAlertHighLimit ( uint16_t limit )

Sets the alert high limit. If alerts are enabled and the measured conversion value is higher than the high limit, an alert is triggered.

Parameters

limit Alert high limit

Returns: 0 (MRAA_SUCCESS) if successful; non-zero otherwise

Here is the caller graph for this function:

mraa_result_t setHysteresis ( uint16_t limit )

Sets the hysteresis value. If a high or low alert condition is triggered, the conversion result must move within the high or low limit by more than this value to clear the alert condition. If the alert hold is set, the alert doesn't self-clear regardless of this value.

Parameters

limit Hysteresis limit