TTP223 Class Reference

API for the TTP223 Touch Sensor. More...

Detailed Description

• ID: ttp223
• Name: Capacitive Touch Sensor
• Other Names: Grove Touch Sensor
• Category: touch
• Manufacturer: seeed
• Link: http://www.seeedstudio.com/depot/Grove-Touch-Sensor-p-747.html
• Connection: gpio

This touch sensor detects when a finger is near the metallic pad by the change in capacitance. It can replace a more traditional push button. The touch sensor can still function when placed under a non-metallic surface like glass or plastic.

    // Create the TTP223 touch sensor object using GPIO pin 0
    upm::TTP223 touch(0);

    // Check whether or not a finger is near the touch sensor and
    // print accordingly, waiting one second between readings
    while (1) {
        if (touch.isPressed()) {
            std::cout << touch.name() << " is pressed" << std::endl;
        } else {
            std::cout << touch.name() << " is not pressed" << std::endl;
        }
        upm_delay(1);
    }

    // Delete the touch sensor object

Public Member Functions
	TTP223 (unsigned int pin)
	~TTP223 ()
std::string	name ()
int	value ()
bool	isPressed ()
void	installISR (mraa::Edge level, void(*isr)(void *), void *arg)
void	uninstallISR ()

Protected Attributes
std::string	m_name
	name of this sensor
mraa_gpio_context	m_gpio
	GPIO pin.
bool	m_isrInstalled

Constructor & Destructor Documentation

TTP223

(

unsigned int

pin

)

TTP223 constructor

Parameters

pin	GPIO pin where the sensor is connected

~TTP223

(

)

TTP223 destructor

Member Function Documentation

std::string name

(

)

Returns the name of this sensor

Returns

Name of this sensor

int value

(

)

Gets the value from the GPIO pin

Returns

Value from the GPIO pin

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bool isPressed

(

)

Determines whether the touch sensor is being touched

Returns

True if touched, false otherwise

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void installISR	(	mraa::Edge	level,
		void(*)(void *)	isr,
		void *	arg
	)

Installs an interrupt service routine (ISR) to be called when the button is activated or deactivated.

Parameters

isr	Pointer to a function to be called on interrupt
arg	Pointer to an object to be supplied as an argument to the ISR.

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void uninstallISR

(

)

Uninstalls the previously installed ISR

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

• src/ttp223/ttp223.hpp
• src/ttp223/ttp223.cxx