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Diffstat (limited to 'peripheral/libupm/src/wheelencoder/wheelencoder.h')
-rw-r--r-- | peripheral/libupm/src/wheelencoder/wheelencoder.h | 132 |
1 files changed, 132 insertions, 0 deletions
diff --git a/peripheral/libupm/src/wheelencoder/wheelencoder.h b/peripheral/libupm/src/wheelencoder/wheelencoder.h new file mode 100644 index 0000000..17356e0 --- /dev/null +++ b/peripheral/libupm/src/wheelencoder/wheelencoder.h @@ -0,0 +1,132 @@ +/* + * 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; + }; +} + + |