Add PWM class as wrapper.

Author: yuuu

mrbgem.rake

@@ -3,4 +3,5 @@ MRuby::Gem::Specification.new('mruby-esp32-ledc') do |spec|
   spec.authors = 'vickash'
 
   spec.cc.include_paths << "#{build.root}/src"
+  spec.add_dependency('mruby-rational', :core => 'mruby-rational')
 end

mrblib/pwm.rb

@@ -0,0 +1,41 @@
+class PWM
+  attr_accessor :group, :channel, :timer, :resolution, :f, :d
+
+  def initialize(pin = nil, **kwargs)
+    self.group = kwargs[:group] || ESP32::LEDC_LOW_SPEED_MODE
+    self.channel = kwargs[:channel] || ESP32::LEDC_CHANNEL_0
+    self.timer = kwargs[:timer] || ESP32::LEDC_TIMER_0
+    self.resolution = kwargs[resolution] || ESP32::LEDC_TIMER_14_BIT
+
+    f = kwargs[:freq] || kwargs[:frequency] || 1000
+    d = kwargs[:duty] || 0
+
+    puts("group=#{group}, channel=#{channel}, timer=#{timer}, resolution=#{resolution}, f=#{f}, d=#{d}")
+
+    ESP32::LEDC.timer_config(group, timer, resolution, f)
+    ESP32::LEDC.channel_config(pin, group, timer, channel)
+
+    self.frequency(f)
+    self.duty(d)
+  end
+
+  def frequency(freq)
+    self.f = freq
+    print(self.f)
+    ESP32::LEDC.set_freq(self.group, self.timer, self.f)
+  end
+
+  def period_us(micro_sec)
+    frequency(Rational(1, Rational(micro_sec, 1_000_000)))
+  end
+
+  def duty(percent)
+    self.d = Rational(percent, 100).to_i
+    ESP32::LEDC.set_duty(self.group, self.channel, self.d)
+  end
+
+  def pulse_width_us(micro_sec)
+    us_per_bit = Rational(1_000_000, self.f) / (2 ** self.resolution)
+    duty((Rational(micro_sec, us_per_bit) * 100).to_i)
+  end
+end