Module: LittleWire::HardwarePWM

Included in:
LittleWire
Defined in:
lib/littlewire/hardware-pwm.rb

Constant Summary collapse

PWMPrescaleSettings =

:nodoc:

[1, 8, 64, 256, 1024]

Instance Attribute Summary collapse

Instance Method Summary collapse

Instance Attribute Details

#hardware_pwm_enabled ⇒ Object

initially :unknown, then a boolean



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# File 'lib/littlewire/hardware-pwm.rb', line 2

def hardware_pwm_enabled
  @hardware_pwm_enabled
end

Instance Method Details

#hardware_pwm ⇒ Object

Get an array of the current values in the Hardware PWM module



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# File 'lib/littlewire/hardware-pwm.rb', line 13

def hardware_pwm; @hardware_pwm.dup; end

#hardware_pwm=(values) ⇒ Object

Set Hardware PWM to an array of new values - array must be two items long



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# File 'lib/littlewire/hardware-pwm.rb', line 16

def hardware_pwm= values
  self.hardware_pwm_enabled = true
  @hardware_pwm[0] = values[0].to_i % 256
  @hardware_pwm[1] = values[1].to_i % 256
  control_transfer(function: :update_pwm_compare, wValue: @hardware_pwm[0].to_i, wIndex: @hardware_pwm[1].to_i)
end

#hardware_pwm_prescale=(division) ⇒ Object

Set division of the Hardware PWM Prescaler - default 1024. This setting controls how quickly LittleWire’s PWM channels oscillate between their ‘high’ and ‘low’ state. Lower prescaler values are often nicer for lighting, while higher values can be better for motor speed control and 1024 is required for servo position control

1024: roughly 63hz
256: roughly 252hz
64: roughly 1khz
8: roughly 8khz
1: roughly 64khz

No other values are accepted



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# File 'lib/littlewire/hardware-pwm.rb', line 45

def hardware_pwm_prescale= division
  raise "Unsupported Hardware PWM Prescale value, must be #{PWMPrescaleSettings.inspect}" unless PWMPrescaleSettings.include? division
  if @hardware_pwm_prescale != division
    @hardware_pwm_prescale = division
    control_transfer(function: :change_pwm_prescale, wValue: PWMPrescaleSettings.index(division))
  end
end

#hardware_pwm_read(channel) ⇒ Object

Get the current value of a Hardware PWM channel (stored in littlewire.rb library - not requested from device)



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# File 'lib/littlewire/hardware-pwm.rb', line 24

def hardware_pwm_read channel; hardware_pwm[get_pin(LittleWire::HardwarePWMPinMap, channel)]; end

#hardware_pwm_write(channel, value) ⇒ Object

Set an individual Hardware PWM channel to a new value in the range of 0-255



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# File 'lib/littlewire/hardware-pwm.rb', line 27

def hardware_pwm_write channel, value
  updated = self.hardware_pwm
  updated[get_pin(LittleWire::HardwarePWMPinMap, channel)] = value
  self.hardware_pwm = updated
end