/* * Author: Brendan Le Foll * Copyright (c) 2014 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 "pwm.h" #include "types.hpp" #include namespace mraa { /** * @brief API to Pulse Width Modulation * * This file defines the PWM interface for libmraa * * @snippet Pwm3-cycle.cpp Interesting */ class Pwm { public: /** * instanciates a PWM object on a pin * * @param pin the pin number used on your board * @param owner if you are the owner of the pin the destructor will * unexport the pin from sysfs, default behaviour is you are the owner * if the pinmapper exported it * @param chipid the pwmchip to use, use only in raw mode */ Pwm(int pin, bool owner = true, int chipid = -1) { if (chipid == -1) { m_pwm = mraa_pwm_init(pin); } else { m_pwm = mraa_pwm_init_raw(chipid, pin); } if (m_pwm == NULL) { throw std::invalid_argument("Error initialising PWM on pin"); } if (!owner) { mraa_pwm_owner(m_pwm, 0); } } /** * Pwm constructor, takes a pointer to the PWM context and * initialises the class * * @param pwm_context void * to a PWM context */ Pwm(void* pwm_context) { m_pwm = (mraa_pwm_context) pwm_context; if (m_pwm == NULL) { throw std::invalid_argument("Invalid PWM context"); } } /** * Pwm destructor */ ~Pwm() { mraa_pwm_close(m_pwm); } /** * Set the output duty-cycle percentage, as a float * * @param percentage A floating-point value representing percentage of * output. The value should lie between 0.0f (representing 0%) and * 1.0f Values above or below this range will be set at either 0.0f or * 1.0f * @return Result of operation */ Result write(float percentage) { return (Result) mraa_pwm_write(m_pwm, percentage); } /** * Read the output duty-cycle percentage, as a float * * @return A floating-point value representing percentage of * output. The value should lie between 0.0f (representing 0%) and * 1.0f Values above or below this range will be set at either 0.0f or * 1.0f */ float read() { return mraa_pwm_read(m_pwm); } /** * Set the PWM period as seconds represented in a float * * @param period Period represented as a float in seconds * @return Result of operation */ Result period(float period) { return (Result) mraa_pwm_period(m_pwm, period); } /** * Set period, milliseconds * * @param ms milliseconds for period * @return Result of operation */ Result period_ms(int ms) { return (Result) mraa_pwm_period_ms(m_pwm, ms); } /** * Set period, microseconds * * @param us microseconds as period * @return Result of operation */ Result period_us(int us) { return (Result) mraa_pwm_period_us(m_pwm, us); } /** * Set pulsewidth, as represented by seconds in a float * * @param seconds The duration of a pulse * @return Result of operation */ Result pulsewidth(float seconds) { return (Result) mraa_pwm_pulsewidth(m_pwm, seconds); } /** * Set pulsewidth, milliseconds * * @param ms milliseconds for pulsewidth * @return Result of operation */ Result pulsewidth_ms(int ms) { return (Result) mraa_pwm_pulsewidth_ms(m_pwm, ms); } /** * The pulsewidth, microseconds * * @param us microseconds for pulsewidth * @return Result of operation */ Result pulsewidth_us(int us) { return (Result) mraa_pwm_pulsewidth_us(m_pwm, us); } /** * Set the enable status of the PWM pin. None zero will assume on with * output being driven and 0 will disable the output * * @param enable enable status of pin * @return Result of operation */ Result enable(bool enable) { return (Result) mraa_pwm_enable(m_pwm, enable); } /** * Get the maximum PWM period in us * * @return max PWM period in us */ int max_period() { return mraa_pwm_get_max_period(m_pwm); } /** * Get the minimum PWM period in us * * @return min PWM period in us */ int min_period() { return mraa_pwm_get_min_period(m_pwm); } private: mraa_pwm_context m_pwm; }; }