# This is a prop controller using a pico, an ultrasonic distance sensor, a dfplayer mp3 player and two LED
# placeholders representing relays to control other objects. Purpose is to trigger multiple events based on 
# distance rather than just motion detection with a PIR.
# PIR sensor input could be used forward of US sensor range as advanced notification to arm the system.
# Possibly use a remote button to arm system to prevent accidental activation.

from machine import Pin
import time
trig = Pin(27, Pin.OUT)
echo = Pin(26, Pin.IN, Pin.PULL_DOWN)
led_1 = Pin(16, Pin.OUT)
mp3 = Pin(14, Pin.OUT, value=0)
led_2 = Pin(6, Pin.OUT, value=0)
has_run = 0 # Bool variable to store whether mp3Play() has run or not so it won't loop.
prev_distance = 500 # Max range of the sensor is ~4 meters, 500 just gives the code a start value to run.

def mp3_Play():
     mp3.on()
     time.sleep(3)
     mp3.off()

while True:
     trig.value(0)
     time.sleep(0.1)
     trig.value(1)
     time.sleep_us(2)
     trig.value(0)
     while echo.value()==0:
          pulse_start = time.ticks_us()
     while echo.value()==1:
          pulse_end = time.ticks_us()
     pulse_duration = pulse_end - pulse_start
     distance = pulse_duration * 17165 / 1000000
     distance = round(distance, 0)
     print ('Distance:',"{:.0f}".format(distance),'cm')

# trigger prop only when distance is DECENDING.
     
     if prev_distance >= distance and distance <= 300 and distance >= 201:
          led_1.on()
     
     elif prev_distance >= distance and distance <= 200 and distance >= 101:
          # makes this function run only once.
          if has_run == 0:
              mp3_Play()
              has_run = 1
          #elif has_run == 1:
          #    pass

     elif prev_distance >= distance and distance <= 100 and distance >= 20:
          led_2.on()

     else: 
          mp3.off()
          led_1.off()
          led_2.off()
          has_run = 0

     time.sleep(1)
     '''
     if prev_distance > distance and if distance <= 300 and distance >= 201:
          led.on()
          #print("Distance is Less")
          #propTrigger()
     if prev_distance < distance:
          print("Distance is More")
     if prev_distance == distance:
          print("Same")
     '''
     prev_distance = distance # Assigns current distance value to prev_distance variable for use in next loop.