WheelEncoder Class Reference

API for the DFRobot Wheel Encoder. More...

Detailed Description

• ID: wheelencoder
• Name: Wheel Encoder
• Category: other
• Manufacturer: dfrobot
• Link: http://www.dfrobot.com/index.php?route=product/product&product_id=98
• Connection: gpio

This sensor was developed for the DFRobot Wheel Encoder, though it could be used for any counting time-based task.

When you instantiate a class of this type, the gpio pin specified is connected to an interrupt. Whenever a low to high transition occurs on the gpio pin, the internal counter is incremented by one.

This class also includes a millisecond counter, so that you can correlate the number of counts to a time period for calculating an RPM or other value as needed.

    // Instantiate a DFRobot Wheel Encoder on digital pin D2
    upm::WheelEncoder sensor(2);

    // set the counter to 0 and start counting
    sensor.clearCounter();
    sensor.startCounter();

    while (shouldRun) {
        // output milliseconds passed and current sensor count
        cout << "Millis: " << sensor.getMillis() << " Count: " << sensor.counter() << endl;

        upm_delay(1);
    }

    sensor.stopCounter();

Public Member Functions
	WheelEncoder (int pin)
	~WheelEncoder ()
uint32_t	getMillis ()
void	initClock ()
void	clearCounter ()
void	startCounter ()
void	stopCounter ()
uint32_t	counter ()

Static Protected Member Functions
static void	wheelISR (void *ctx)

Protected Attributes
mraa::Gpio	m_gpio

Constructor & Destructor Documentation

WheelEncoder

(

int

pin

)

DFRobot Wheel Encoder sensor constructor

Parameters

pin	Digital pin to use

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~WheelEncoder

(

)

WheelEncoder destructor

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Member Function Documentation

uint32_t getMillis

(

)

Returns the number of milliseconds elapsed since initClock() was last called.

Returns

Elapsed milliseconds

void initClock

(

)

Resets the clock

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void clearCounter ( )

inline

Resets the counter to 0. The counter should be stopped via stopCounter() prior to calling this function.

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void startCounter

(

)

Starts the counter. This function will also clear the current count and reset the clock.

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void stopCounter

(

)

Stops the counter

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uint32_t counter ( )

inline

Gets the current counter value

Returns

counter value

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

• src/wheelencoder/wheelencoder.hpp
• src/wheelencoder/wheelencoder.cxx