fun buzz(delay: Float, times: Int)
	do
		assert times > 0
		assert delay > 0.0
		var delay_i = (delay*1000.0).to_i
		for i in [0..times[ do
			pin.write(true)
			delay_i.bcm2835_delay_micros
			pin.write(false)
			delay_i.bcm2835_delay_micros
		end
	end