#!/usr/bin/env python3
# For controlling a RUN display based on Stranger Things
#  (c) 2018 Bradley Knockel


# Using a motion detector (PIR sensor) is optional.
# Detects infrared, so is not fooled by shadows,
# but it does not work through windows.
# I'm using an HC-SR501.
# With the HC-SR501 facing away from you,
# and the 3 pins at the bottom...
#   left pin   --> 5V
#   middle pin --> GPIO 25
#   right pin  --> GND
# HC-SR501 requires nearly a minute to initialize.
# During this period, it can and often will output
# false detection signals.


# Perhaps using a photocell (LDR) is better?
# Sees through glass, so you can have a sign having
# people put their finger over the LDR as if it were
# a button that works through glass!
# Use a resistor and LDR to create a "potentiometer"...
#   Photocell              -> 3.3V
#   Photocell and resistor -> ADC pin1 (channel 0)
#   resistor               -> GND
# Using a larger fixed resistor uses less
# power and is necessary if very dark,
# but it gives less resolution for
# measuring bright things.
# Using a smaller fixed resistor gives less
# resolution for measuring dark things, but
# is needed for very bright situations.
# 10,000 ohms is reasonable.
# For safety, do not use less than 220 ohms.
# In a very dark room, use at least 100,000 ohms.
# My LDR is model KLS6-3537.
#
# If using a photocell, here are the ADC (MCP3008) pins...
#   VDD (16) to 3.3V
#   VREF (15) to 3.3V
#   AGND (14) to GND
#   CLK (13) to GPIO 11  (sclk) (must be at least 10 kHz)
#   DOUT (12) to GPIO 9  (miso)
#   DIN (11) to GPIO 10  (mosi)
#   CS/SHDN (10) to GPIO 8  (ce0) (must be pulled HIGH/off between conversions)
#   DGND (9) to GND
#
# If using hardware SPI, make sure you've enabled SPI using
#   sudo raspi-config    (in Interface Options)
# Then reboot the Pi.
#
# To install the Adafruit modules for ADC...
#   sudo apt-get install python3-pip
#   sudo pip3 install adafruit-mcp3008



# Are you using a motion detector?
motionDetector = False
pirPin = 25


# Are you using a light detector?
# This will override motionDetector if True.
lightDetector = True
# seconds between sampling brightness
waitTime = 0.4
# higher is harder to activate, but lower is susceptible to electrical noise
thresholdFraction = 0.2



# set pins
pinR = 21
pinU = 20
pinN = 16
pinRemaining = 12





import time
import random
random.seed()


import RPi.GPIO as IO
IO.setmode(IO.BCM)
IO.setup(pinR, IO.OUT)
IO.setup(pinU, IO.OUT)
IO.setup(pinN, IO.OUT)
IO.setup(pinRemaining, IO.OUT)



if lightDetector:
  motionDetector = False

  import Adafruit_MCP3008

  ## Software SPI configuration:
  #CLK  = 11
  #MISO = 9
  #MOSI = 10
  #CS   = 8
  #mcp = Adafruit_MCP3008.MCP3008(clk=CLK, cs=CS, miso=MISO, mosi=MOSI)
     
  ## Hardware SPI configuration:
  import Adafruit_GPIO.SPI as SPI   # Adafruit's spidev module
  mcp = Adafruit_MCP3008.MCP3008(spi=SPI.SpiDev(0,0))

  def getBrightness():
    val = mcp.read_adc(0)
    print(val)
    # add 0.5 to prevent getting 0
    voltsR = (val+0.5)/1024.0    # ratio of (volts / 3.3V) across fixed resistor
    return voltsR/(1-voltsR)

if motionDetector:
  IO.setup(pirPin, IO.IN)




def turnOff():
  IO.output(pinR, 0)
  IO.output(pinU, 0)
  IO.output(pinN, 0)
  IO.output(pinRemaining, 0)

def turnOn():
  IO.output(pinR, 1)
  IO.output(pinU, 1)
  IO.output(pinN, 1)
  IO.output(pinRemaining, 1)

turnOff()




def getAttention():
  turnOn()
  time.sleep(0.1)
  turnOff()
  time.sleep(0.1)
  turnOn()
  time.sleep(0.1)
  turnOff()




def go():

  IO.output(pinR, 1)
  time.sleep(1.5)
  IO.output(pinR, 0)
  time.sleep(0.5)

  IO.output(pinU, 1)
  time.sleep(2)
  IO.output(pinU, 0)
  time.sleep(0.5)

  IO.output(pinN, 1)
  time.sleep(3)
  IO.output(pinN, 0)
  time.sleep(0.5)

  # flicker all the lights
  t = time.time()
  while time.time() < t + 5.0:
    if random.randrange(2) == 1: turnOff()
    else: turnOn()
    time.sleep(0.04)
  turnOff()






justWent = False

try:


  while 1:

    if motionDetector:

      if IO.input(pirPin):
        if not justWent:
          getAttention()
          time.sleep(1)
        justWent = True
        go()
        time.sleep(1)
      else:
        justWent = False




    elif lightDetector:

      val1 = getBrightness()
      time.sleep(waitTime)
      val2 = getBrightness()
      #print(val1*100000, val2*100000)
      if  abs(val1-val2)*2/(val1+val2) > thresholdFraction:
        if not justWent:
          getAttention()
          time.sleep(1)
        justWent = True
        go()
        time.sleep( max(1.0 - waitTime, 0.01) )
      else:
        justWent = False




    else:
      go()
      time.sleep(5)




except:
  pass

# cleanup
turnOff()
IO.cleanup()