Description

ABSTRACT

Nowadays everything becomes autonomous, thus to turn watering system for plants in fields or home plants to autonomous this beginner Raspberry Pi project helps you to interface Soil moisture sensor and motor with the Raspberry Pi using MCP3008 and also by interfacing the water level sensor with Raspberry Pi, over flow of water can be prevented. When the system begins to run the program it will check for soil moisture using moisture sensor, if it doesn’t have any moisture in the soil, motor turned on and water get passed to the field. Then priority hands over to level sensor, if the water level reaches the threshold, motor get turned off. So this Raspberry Pi system makes watering system to be autonomous.

 

HARDWARE REQUIRED

• Raspberry Pi
• SD card
• Power supply
• VGA to HDMI converter (Optional)
• MCP3008 (ADC IC)
• Moisture sensor
• Level sensor
• Motor

 

SOFTWARE REQUIRED

• Raspbian Stretch OS      
• SD card Formatter
• Win32DiskImager (or) Etcher

PYTHON LIBRARIES USED

• RPi.GPIO as GPIO (To access the GPIO Pins of Raspberry Pi)
• Time library (For Time delay)

CODE

import RPi.GPIO as GPIO

GPIO.setmode(GPIO.BCM)

# read SPI data from MCP3008 chip, 8 possible adc's (0 thru 7)
def readadc(adcnum, clockpin, mosipin, misopin, cspin):
    if ((adcnum > 7) or (adcnum < 0)):
        return -1
    GPIO.output(cspin, True)

    GPIO.output(clockpin, False)  # start clock low
    GPIO.output(cspin, False)  # bring CS low

    commandout = adcnum
    commandout |= 0x18  # start bit + single-ended bit
    commandout <<= 3  # we only need to send 5 bits here
    for i in range(5):
        if (commandout & 0x80):
            GPIO.output(mosipin, True)
        else:
            GPIO.output(mosipin, False)
        commandout <<= 1
        GPIO.output(clockpin, True)
        GPIO.output(clockpin, False)

    adcout = 0
    # read in one empty bit, one null bit and 10 ADC bits
    for i in range(12):
        GPIO.output(clockpin, True)
        GPIO.output(clockpin, False)
        adcout <<= 1
        if (GPIO.input(misopin)):
            adcout |= 0x1

    GPIO.output(cspin, True)

    adcout >>= 1  # first bit is 'null' so drop it
    return adcout


# change these as desired - they're the pins connected from the
# SPI port on the ADC to the Cobbler
SPICLK = 18
SPIMISO = 23
SPIMOSI = 24
SPICS = 25
motor=21
# set up the SPI interface pins
GPIO.setup(SPIMOSI, GPIO.OUT)
GPIO.setup(SPIMISO, GPIO.IN)
GPIO.setup(SPICLK, GPIO.OUT)
GPIO.setup(SPICS, GPIO.OUT)
GPIO.setup(motor, GPIO.OUT)


while True:
    # read the analog pin
    Moisture_level = readadc(0, SPICLK, SPIMOSI, SPIMISO, SPICS)
    print("Moisture_level:", Moisture_level)
    Water_level = readadc(1, SPICLK, SPIMOSI, SPIMISO, SPICS)
    print("Water_level:", Water_level)
    if((Moisture_level>500)and(Water_level<500)):
        GPIO.output(motor, True)
    else:
        GPIO.output(motor, False)