1 /* 2 * Author: Brendan Le Foll <brendan.le.foll (at) intel.com> 3 * Copyright (c) 2014 Intel Corporation. 4 * 5 * Permission is hereby granted, free of charge, to any person obtaining 6 * a copy of this software and associated documentation files (the 7 * "Software"), to deal in the Software without restriction, including 8 * without limitation the rights to use, copy, modify, merge, publish, 9 * distribute, sublicense, and/or sell copies of the Software, and to 10 * permit persons to whom the Software is furnished to do so, subject to 11 * the following conditions: 12 * 13 * The above copyright notice and this permission notice shall be 14 * included in all copies or substantial portions of the Software. 15 * 16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 17 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF 18 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 19 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE 20 * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION 21 * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION 22 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. 23 */ 24 25 #pragma once 26 27 #include "pwm.h" 28 #include "types.hpp" 29 #include <stdexcept> 30 31 namespace mraa 32 { 33 34 /** 35 * @brief API to Pulse Width Modulation 36 * 37 * This file defines the PWM interface for libmraa 38 * 39 * @snippet Pwm3-cycle.cpp Interesting 40 */ 41 class Pwm 42 { 43 public: 44 /** 45 * instanciates a PWM object on a pin 46 * 47 * @param pin the pin number used on your board 48 * @param owner if you are the owner of the pin the destructor will 49 * @param chipid the pwmchip to use, use only in raw mode 50 * unexport the pin from sysfs, default behaviour is you are the owner 51 * if the pinmapper exported it 52 */ 53 Pwm(int pin, bool owner = true, int chipid = -1) 54 { 55 if (chipid == -1) { 56 m_pwm = mraa_pwm_init(pin); 57 } else { 58 m_pwm = mraa_pwm_init_raw(chipid, pin); 59 } 60 61 if (m_pwm == NULL) { 62 throw std::invalid_argument("Error initialising PWM on pin"); 63 } 64 65 if (!owner) { 66 mraa_pwm_owner(m_pwm, 0); 67 } 68 } 69 /** 70 * Pwm destructor 71 */ 72 ~Pwm() 73 { 74 mraa_pwm_close(m_pwm); 75 } 76 /** 77 * Set the output duty-cycle percentage, as a float 78 * 79 * @param percentage A floating-point value representing percentage of 80 * output. The value should lie between 0.0f (representing on 0%) and 81 * 1.0f Values above or below this range will be set at either 0.0f or 82 * 1.0f 83 * @return Result of operation 84 */ 85 Result 86 write(float percentage) 87 { 88 return (Result) mraa_pwm_write(m_pwm, percentage); 89 } 90 /** 91 * Read the ouput duty-cycle percentage, as a float 92 * 93 * @return A floating-point value representing percentage of 94 * output. The value should lie between 0.0f (representing on 0%) and 95 * 1.0f Values above or below this range will be set at either 0.0f or 96 * 1.0f 97 */ 98 float 99 read() 100 { 101 return mraa_pwm_read(m_pwm); 102 } 103 /** 104 * Set the PWM period as seconds represented in a float 105 * 106 * @param period Period represented as a float in seconds 107 * @return Result of operation 108 */ 109 Result 110 period(float period) 111 { 112 return (Result) mraa_pwm_period(m_pwm, period); 113 } 114 /** 115 * Set period, milliseconds 116 * 117 * @param ms milliseconds for period 118 * @return Result of operation 119 */ 120 Result 121 period_ms(int ms) 122 { 123 return (Result) mraa_pwm_period_ms(m_pwm, ms); 124 } 125 /** 126 * Set period, microseconds 127 * 128 * @param us microseconds as period 129 * @return Result of operation 130 */ 131 Result 132 period_us(int us) 133 { 134 return (Result) mraa_pwm_period_us(m_pwm, us); 135 } 136 /** 137 * Set pulsewidth, As represnted by seconds in a (float) 138 * 139 * @param seconds The duration of a pulse 140 * @return Result of operation 141 */ 142 Result 143 pulsewidth(float seconds) 144 { 145 return (Result) mraa_pwm_pulsewidth(m_pwm, seconds); 146 } 147 /** 148 * Set pulsewidth, milliseconds 149 * 150 * @param ms milliseconds for pulsewidth 151 * @return Result of operation 152 */ 153 Result 154 pulsewidth_ms(int ms) 155 { 156 return (Result) mraa_pwm_pulsewidth_ms(m_pwm, ms); 157 } 158 /** 159 * The pulsewidth, microseconds 160 * 161 * @param us microseconds for pulsewidth 162 * @return Result of operation 163 */ 164 Result 165 pulsewidth_us(int us) 166 { 167 return (Result) mraa_pwm_pulsewidth_us(m_pwm, us); 168 } 169 /** 170 * Set the enable status of the PWM pin. None zero will assume on with 171 * output being driven and 0 will disable the output 172 * 173 * @param enable enable status of pin 174 * @return Result of operation 175 */ 176 Result 177 enable(bool enable) 178 { 179 if (enable) 180 return (Result) mraa_pwm_enable(m_pwm, 1); 181 else 182 return (Result) mraa_pwm_enable(m_pwm, 0); 183 } 184 /** 185 * Set the period and duty of a PWM object. 186 * 187 * @param period represented in ms. 188 * @param duty represnted in ms as float. 189 * @return Result of operation 190 */ 191 Result 192 config_ms(int period, float duty) 193 { 194 return (Result) mraa_pwm_config_ms(m_pwm, period, duty); 195 } 196 /** 197 * Set the period and duty (percent) of a PWM object. 198 * 199 * @param period as represented in ms. 200 * @param duty percentage i.e. 50% = 0.5f 201 * @return Result of operation 202 */ 203 Result 204 config_percent(int period, float duty) 205 { 206 return (Result) mraa_pwm_config_percent(m_pwm, period, duty); 207 } 208 /** 209 * Get the maximum pwm period in us 210 * 211 * @return max pwm in us 212 */ 213 int 214 max_period() 215 { 216 return mraa_pwm_get_max_period(); 217 } 218 /** 219 * Get the minimum pwm period in us 220 * 221 * @return min pwm in us 222 */ 223 int 224 min_period() 225 { 226 return mraa_pwm_get_min_period(); 227 } 228 229 private: 230 mraa_pwm_context m_pwm; 231 }; 232 } 233
