1 // Copyright 2013 Olivier Gillet. 2 // 3 // Author: Olivier Gillet (ol.gillet@gmail.com) 4 // 5 // Permission is hereby granted, free of charge, to any person obtaining a copy 6 // of this software and associated documentation files (the "Software"), to deal 7 // in the Software without restriction, including without limitation the rights 8 // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell 9 // copies of the Software, and to permit persons to whom the Software is 10 // furnished to do so, subject to the following conditions: 11 // 12 // The above copyright notice and this permission notice shall be included in 13 // all copies or substantial portions of the Software. 14 // 15 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 16 // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 17 // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 18 // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 19 // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 20 // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN 21 // THE SOFTWARE. 22 // 23 // See http://creativecommons.org/licenses/MIT/ for more information. 24 // 25 // ----------------------------------------------------------------------------- 26 // 27 // Driver for PWM (controlling VCF). 28 29 #ifndef STREAMS_DRIVERS_PWM_H_ 30 #define STREAMS_DRIVERS_PWM_H_ 31 32 #include "stmlib/stmlib.h" 33 34 #include <stm32f10x_conf.h> 35 36 namespace streams { 37 38 const uint16_t kPwmResolution = 10; // 10 bits -> 70kHz PWM. 39 40 class Pwm { 41 public: Pwm()42 Pwm() { } ~Pwm()43 ~Pwm() { } 44 45 void Init(); 46 Write(uint8_t channel,uint16_t value)47 void Write(uint8_t channel, uint16_t value) { 48 filtered_value_[channel] += (value - filtered_value_[channel]) >> 4; 49 uint16_t channel_value = filtered_value_[channel] >> (16 - kPwmResolution); 50 if (channel == 0) { 51 TIM1->CCR3 = channel_value; 52 } else { 53 TIM1->CCR4 = channel_value; 54 } 55 } 56 57 private: 58 uint16_t filtered_value_[2]; 59 DISALLOW_COPY_AND_ASSIGN(Pwm); 60 }; 61 62 } // namespace streams 63 64 #endif // STREAMS_DRIVERS_DAC_H_ 65