pwm_output.h

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#ifndef SENSESP_SYSTEM_PWM_OUTPUT_H
#define SENSESP_SYSTEM_PWM_OUTPUT_H
 
#include <Arduino.h>
#include <map>
 
#include "esp_arduino_version.h"
#include "valueconsumer.h"
 
namespace sensesp {

class PWMOutput : public ValueConsumer<float> {
 public:
  PWMOutput(int pin = -1, int pwm_channel = -1, int channel_frequency = 5000,
            int channel_resolution = 13) __attribute__((deprecated))
      : ValueConsumer<float>(),
        pwm_channel_{static_cast<uint8_t>(pwm_channel)},
        channel_frequency_{channel_frequency},
        channel_resolution_{channel_resolution},
        pwmrange_{static_cast<int>((1 << channel_resolution) - 1)} {
    if (pin >= 0) {
      pwm_channel_ = assign_channel(pin, pwm_channel);
    }
  }

  virtual void set(const float& new_value) override { set_pwm(new_value); }
 
 protected:
  int channel_frequency_;
  int channel_resolution_;
  int pwmrange_;
 
  static std::map<uint8_t, int8_t>& channel_map() {
    static std::map<uint8_t, int8_t> channel_to_pin_;
    return channel_to_pin_;
  }
 
  uint8_t pwm_channel_{};

  int assign_channel(int pin, int pwm_channel = -1) {
    if (pwm_channel == -1) {
      // Do a search for the next available channel
      std::map<uint8_t, int8_t>::iterator it;
      pwm_channel = 0;
      do {
        pwm_channel++;
        it = channel_map().find(pwm_channel);
      } while (it != channel_map().end());
    }
 
    channel_map()[pwm_channel] = pin;
 
    ESP_LOGD(__FILENAME__, "PWM channel %d assigned to pin %d", pwm_channel,
             pin);
 
    pinMode(pin, OUTPUT);
#if ESP_ARDUINO_VERSION_MAJOR > 2
    ledcAttachChannel(pin, channel_frequency_, channel_resolution_,
                      pwm_channel);
#else
    ledcSetup(pwm_channel, channel_frequency_, channel_resolution_);
    ledcAttachPin(pin, pwm_channel);
#endif
 
    return pwm_channel;
  }

  void set_pwm(float value) {
    std::map<uint8_t, int8_t>::iterator it;
    it = channel_map().find(pwm_channel_);
    if (it != channel_map().end()) {
      int pin = it->second;
      int const output_val = value * pwmrange_;
      // ESP_LOGD(__FILENAME__, "Setting PWM channel %d to %d", pwm_channel_,
      //          output_val);
#if ESP_ARDUINO_VERSION_MAJOR > 2
      ledcWriteChannel(pwm_channel_, output_val);
#else
      ledcWrite(pwm_channel_, output_val);
#endif
    } else {
      ESP_LOGW(__FILENAME__,
               "No pin assigned to channel %d. Ignoring set_pwm()",
               pwm_channel_);
    }
  }
};
 
}  // namespace sensesp
 
#endif