Plant Babysitter

# ------------------------------------------------------------------------
# Constants
# ------------------------------------------------------------------------
import time
# Peripheral path
GPIO_BASE_PATH               = "/sys/class/gpio" #sets up path to get to file
ADC_BASE_PATH                = "/sys/bus/iio/devices/iio:device0" #sets up path to get to file

# GPIO direction
IN                           = True #Gpio is receiving input (we don't have this)
OUT                          = False #Gpio is outputting (this is what we have)

# GPIO output state
LOW                          = "0" #basically off
HIGH                         = "1" #basically on

GPIO_VAL                     = (0, 5)  # gpio5 in tupple form

# Moisture Sensor ADC input
SensorReading                = "in_voltage6_raw" # AIN6   (this is the file name)
TempReading                  = "in_voltage5_raw" # AIN5

# ------------------------------------------------------------------------
# FUNCTIONS
# ------------------------------------------------------------------------
import os

def gpio_setup(gpio, direction, default_value=False):
    """Setup GPIO pin
    
      * Test if GPIO exists; if not create it
      * Set direction
      * Set default value
    """
    #This is borrowed from whac-a-mole code
    
    gpio_number = str((gpio[0] * 32) + gpio[1])
    path        = "{0}/gpio{1}".format(GPIO_BASE_PATH, gpio_number)
    
    if not os.path.exists(path):
        # "echo {gpio_number} > {GPIO_BASE_PATH}/export"
        print("Create GPIO: {0}".format(gpio_number))
        with open("{0}/export".format(GPIO_BASE_PATH), 'w') as f:
            f.write(gpio_number)
    
    if direction:
        # "echo in > {path}/direction"
        with open("{0}/direction".format(path), 'w') as f:
            f.write("in")
    else:
        # "echo out > {path}/direction"
        with open("{0}/direction".format(path), 'w') as f:
            f.write("out")
        
    if default_value:
        # "echo {default_value} > {path}/value"
        with open("{0}/value".format(path), 'w') as f:
            f.write(default_value)
# End def


def gpio_set(gpio, value):
    """Set GPIO ouptut value."""
    gpio_number = str((gpio[0] * 32) + gpio[1])
    path        = "{0}/gpio{1}".format(GPIO_BASE_PATH, gpio_number)
    
    # "echo {value} > {path}/value"
    with open("{0}/value".format(path), 'w') as f:
        f.write(value)
# End def


def adc_get(channel):
    """Get ADC input value.
    Returns:
        value (float):  Value will be between 0 (0V) and 1.0 (3.3V)."""
        #channel is the adc raw input that we defined as SensorReading
    with open("{0}/{1}".format(ADC_BASE_PATH, channel), 'r') as f:
        out = f.read()
    
    return float(float(out) / float(4096)) #returns the analog number in decimal form (between 0 and 1)
# End def


def turn_off_moisture_sensor():
    """Turn off the moisture sensor 
    """
    gpio_set(GPIO_VAL, LOW)
# End def


def turn_on_moisture_sensor():
    """Turn on the moisture sensor
    """
    gpio_set(GPIO_VAL, HIGH)
# End def


def setup_sensor():
    """Setup all the pins for the reading.
    """
    gpio_setup(GPIO_VAL, OUT, LOW)
#End def

# ------------------------------------------------------------------------
# SEMI-DRIVERS?
# ------------------------------------------------------------------------

def read_moisture():
    """ set up stuff and read moisture level"""
    setup_sensor()
    turn_on_moisture_sensor()
    moisture = adc_get(SensorReading)
    turn_off_moisture_sensor()
    return moisture

#End def

def water_plant():
    """activates the servo motor to water the plant
    """ 
    import Adafruit_BBIO.PWM as PWM
    import time
    
    servo_pin = "P2_3"
    duty_min = 3
    duty_max = 14.5
    duty_span = duty_max - duty_min

    PWM.start(servo_pin, (100-duty_min), 20.0)
    duty = 4
    PWM.set_duty_cycle(servo_pin, duty)
    time.sleep(1.0)
    
    PWM.stop(servo_pin)
    PWM.cleanup()
    time.sleep(2.0)
    
    PWM.start(servo_pin, (100-duty_min), 20.0)
    duty = 1.5
    PWM.set_duty_cycle(servo_pin, duty)
    time.sleep(1.0)

    PWM.stop(servo_pin)
    PWM.cleanup()


#End def

def setup():
    setup_sensor()
#End def


def read_temp2():
    tempAnalog = adc_get(TempReading)
    tempMV = tempAnalog * 3300
    temp_c = (tempMV - 500) / 10
    temp_f = (temp_c * 9/5) + 32
    temperature = ('C=%d F=%d' % (temp_c, temp_f))
    return temperature
    time.sleep(1)
    
    return temperature
#End def

# ------------------------------------------------------------------------
# MAIN DRIVER
# ------------------------------------------------------------------------
def main():
    setup()
    
    while (True):
        moisture = read_moisture()
        temperature = read_temp2()
        print("Temperature: {0}".format(temperature))
        print("Moisture Level = {0}".format(moisture))
        if (moisture < 0.5):
            print("Moisture low, watering plant")
            water_plant()
        else:
            print("All is well!")
        
        time.sleep(60.0) #sleeps for 1 minute
#End def


main()