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/*
* Author: Jon Trulson <jtrulson@ics.com>
* Copyright (c) 2015 Intel Corporation.
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
* LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
* OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
* WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
#pragma once
#include <string>
#include <stdint.h>
#include <sys/time.h>
#include <mraa/gpio.hpp>
namespace upm {
/**
* @brief DFRobot Wheel Encoder library
* @defgroup wheelencoder libupm-wheelencoder
* @ingroup dfrobot gpio other
*/
/**
* @library wheelencoder
* @sensor wheelencoder
* @comname DFRobot Wheel Encoder
* @type other
* @man dfrobot
* @web http://www.dfrobot.com/index.php?route=product/product&product_id=98
* @con gpio
* @brief API for the DFRobot Wheel Encoder
*
* 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.
*
* @image html wheelencoder.jpg
* @snippet wheelencoder.cxx Interesting
*/
class WheelEncoder {
public:
/**
* DFRobot Wheel Encoder sensor constructor
*
* @param pin Digital pin to use
*/
WheelEncoder(int pin);
/**
* WheelEncoder destructor
*/
~WheelEncoder();
/**
* Returns the number of milliseconds elapsed since initClock()
* was last called.
*
* @return Elapsed milliseconds
*/
uint32_t getMillis();
/**
* Resets the clock
*
*/
void initClock();
/**
* Resets the counter to 0. The counter should be
* stopped via stopCounter() prior to calling this function.
*
*/
void clearCounter() { m_counter = 0; };
/**
* Starts the counter. This function will also clear the current
* count and reset the clock.
*
*/
void startCounter();
/**
* Stops the counter
*
*/
void stopCounter();
/**
* Gets the current counter value
*
* @return counter value
*/
uint32_t counter() { return m_counter; };
protected:
mraa::Gpio m_gpio;
static void wheelISR(void *ctx);
private:
volatile uint32_t m_counter;
struct timeval m_startTime;
bool m_isrInstalled;
};
}
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