MPR121 Class Reference

C++ API for the MPR121 I2C touch sensor. More...

Detailed Description

• ID: mpr121
• Name: mpr121 touch sensor
• Category: touch
• Manufacturer: seeed
• Link: http://www.seeedstudio.com/wiki/Grove_-_I2C_Touch_Sensor
• Connection: i2c

UPM module for the MPR121 touch sensor

  // Instantiate an MPR121 on I2C bus 0

  upm::MPR121 *touch = new upm::MPR121(MPR121_I2C_BUS, MPR121_DEFAULT_I2C_ADDR);

  // init according to AN3944 defaults
  touch->configAN3944();

  while (shouldRun)
    {
      touch->readButtons();
      printButtons(touch);
      sleep(1);
    }

Public Member Functions
	MPR121 (int bus, uint8_t address=MPR121_DEFAULT_I2C_ADDR)
	~MPR121 ()
bool	configAN3944 ()
void	readButtons ()
mraa_result_t	writeBytes (uint8_t reg, uint8_t *buffer, unsigned int len)
void	readBytes (uint8_t reg, uint8_t *buffer, unsigned int len)

Data Fields
uint16_t	m_buttonStates
bool	m_overCurrentFault

Constructor & Destructor Documentation

MPR121	(	int	bus,
		uint8_t	address = MPR121_DEFAULT_I2C_ADDR
	)

mpr121 touch sensor constructor

Parameters

bus	i2c bus to use

~MPR121

(

)

MPR121 Destructor

Member Function Documentation

bool configAN3944

(

)

Setup a default configuration, based on Application Note 3944 (AN3944): http://cache.freescale.com/files/sensors/doc/app_note/AN3944.pdf

After configuration, the sensor will be left in the Run State.

Returns

True if configuration succeeded

void readButtons

(

)

Read the button states into the m_buttonStates member variable. Also set the m_overCurrentFault variable if an over current is detected.

mraa_result_t writeBytes	(	uint8_t	reg,
		uint8_t *	buffer,
		unsigned int	len
	)

Write value(s) into registers

Parameters

reg	register location to start writing into
buffer	buffer for data storage
len	number of bytes to write

Returns

mraa_result_t

void readBytes	(	uint8_t	reg,
		uint8_t *	buffer,
		unsigned int	len
	)

Read value(s) from registers

Parameters

reg	register location to start reading from
buffer	buffer for data storage
len	number of bytes to read

Field Documentation

uint16_t m_buttonStates

button states

bool m_overCurrentFault

Over current fault detected

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The documentation for this class was generated from the following files:

• /var/lib/jenkins/workspace/upm-doc-stable/src/mpr121/mpr121.h
• /var/lib/jenkins/workspace/upm-doc-stable/src/mpr121/mpr121.cxx