Module: UsbPdMatch::Negotiator

Defined in:
lib/usb_pd_match/negotiator.rb

Overview

Negotiates the optimal fixed-PDO contract between a charger and a device, mirroring how a real USB-C PD sink picks the highest mutually-supported voltage and the current both sides can sustain.

Class Method Summary collapse

Class Method Details

.full_power?(charger, device) ⇒ Boolean

True when the device will charge at its full rated power on this charger.

Returns:

  • (Boolean) 


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# File 'lib/usb_pd_match/negotiator.rb', line 58

def full_power?(charger, device)
  result = negotiate(charger, device)
  result ? result.full_power? : false
end

.negotiate(charger, device) ⇒ Object

Returns a Result, or nil if there is no mutually supported voltage.



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# File 'lib/usb_pd_match/negotiator.rb', line 36

def negotiate(charger, device)
  candidates = charger.pdos.select do |voltage, _charger_current|
    voltage <= device.max_voltage
  end
  return nil if candidates.empty?

  best = candidates.map do |voltage, charger_current|
    current = [charger_current, device.current_ceiling_at(voltage)].min
    [voltage, current, (voltage * current).round(2)]
  end.max_by { |voltage, _current, watts| [watts, voltage] } # tie → higher voltage (lower loss)

  Result.new(voltage: best[0], current: best[1], watts: best[2],
             charger: charger, device: device)
end

.watts(charger, device) ⇒ Object

Convenience: just the delivered wattage (0.0 if incompatible).



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# File 'lib/usb_pd_match/negotiator.rb', line 52

def watts(charger, device)
  result = negotiate(charger, device)
  result ? result.watts : 0.0
end