#L8a - Program control sensor cu ultrasunete de tip
# HC-SR04 uilizat pentru generare sunete 
# Conexiuni:
# Vcc  - 5V
# trig - pin 24 (GP18)
# echo - pin 25 (GP19)
# GND  - GND
# Difuzor -pin 21 (Gp16)

from machine import Pin, PWM
import utime

trig=Pin(18, Pin.OUT)
echo=Pin(19, Pin.IN, machine.Pin.PULL_UP)
led=Pin(25, Pin.OUT)
sound=PWM(Pin(16))
trig.value(0)      # initializare
led.value(0)

do=440
re=494
mi=523
fa=587
sol=659
la=698
si=784

while 1:                   # bucla infinita
	trig.value(1)      # start trig
	utime.sleep(0.00001) # 10 microsecunde
	trig.value(0)        # porneste emisie US


	while echo()==0:
		start_t=utime.ticks_us() # in 1 iese cu ultima valoare
	while echo()==1:
		stop_t=utime.ticks_us() # in 0 iese cu ultima valoare
	durata=stop_t - start_t         # durata dus-intors ultrasunete
        dist= durata*342/2/10000      # in cm
	
        print("%.2f" % dist, "cm")    # afisare distanta
        if 2 < dist < 4 :
		sound.freq(do) # 
		sound.duty_u16(32000) # 50 %
		utime.sleep(0.3)
        if 4 < dist < 6 :
		sound.freq(re) # 
		sound.duty_u16(32000) # 50 %
		utime.sleep(0.3)

        if 6 < dist < 8 :
		sound.freq(mi) # 
		sound.duty_u16(32000) # 50 %
		utime.sleep(0.3)

        if 8 < dist < 10 :
		sound.freq(fa) # 
		sound.duty_u16(32000) # 50 %
		utime.sleep(0.3)

        if 10 < dist < 12 :
		sound.freq(sol) # 
		sound.duty_u16(32000) # 50 %
		utime.sleep(0.3)

        if 12 < dist < 14 :
		sound.freq(la) # 
		sound.duty_u16(32000) # 50 %
		utime.sleep(0.3)

        if 14 < dist < 16 :
		sound.freq(si) # 
		sound.duty_u16(32000) # 50 %
		utime.sleep(0.3)

        else:
		sound.deinit() # stop sunet
	utime.sleep(0.1)           # secunde