water.py

# External module imp
import RPi.GPIO as GPIO
import datetime
import time

init = False

GPIO.setmode(GPIO.BOARD) # Broadcom pin-numbering scheme

def get_last_watered():
    try:
        f = open("last_watered.txt", "r")
        return f.readline()
    except:
        return "NEVER!"
      
def get_status(pin = 8):
    GPIO.setup(pin, GPIO.IN) 
    return GPIO.input(pin)

def init_output(pin):
    GPIO.setup(pin, GPIO.OUT)
    GPIO.output(pin, GPIO.LOW)
    GPIO.output(pin, GPIO.HIGH)
    
def auto_water(delay = 5, pump_pin = 7, water_sensor_pin = 8):
    consecutive_water_count = 0
    init_output(pump_pin)
    print("Here we go! Press CTRL+C to exit")
    try:
        while 1 and consecutive_water_count < 10:
            time.sleep(delay)
            wet = get_status(pin = water_sensor_pin) == 0
            if not wet:
                if consecutive_water_count < 5:
                    pump_on(pump_pin, 1)
                consecutive_water_count += 1
            else:
                consecutive_water_count = 0
    except KeyboardInterrupt: # If CTRL+C is pressed, exit cleanly:
        GPIO.cleanup() # cleanup all GPI

def pump_on(pump_pin = 7, delay = 1):
    init_output(pump_pin)
    f = open("last_watered.txt", "w")
    f.write("Last watered {}".format(datetime.datetime.now()))
    f.close()
    GPIO.output(pump_pin, GPIO.LOW)
    time.sleep(1)
    GPIO.output(pump_pin, GPIO.HIGH)
    

I've got this error:

File "water.py", line 50, in
GPIO.output(pump_pin, GPIO.HIGH)
NameError: name 'pump_pin' is not defined

You can see line 43 pump_pin is assigned a default value of 7. Can you confirm all lines 44-50 are indented properly so they're a part of "pump_on" ?

a brief explanation on how the code works would be nice

Traceback (most recent call last):
File "<pyshell#1>", line 1, in
import water
ImportError: No module named 'water'

what does this mean

Hi,
I have a problem with your schema. How can you use an Analog output from the moisture sensor? I always get 1 either in water or without water?

Do you use any trick?
Cheers
Luigi

def pump_on(pump_pin = 7, delay = 1): time.sleep(1)

I believe you intended to use "delay" as the input to time.sleep()

Nice and simple, I like it. I like the external power source for the water pump in the design. Great example of using a relay in a circuit especially if the circuit is expanded to more than one plant and pump.

Shouldn't you use a MCP3008 analog to digital converter for the water sensor? Plus allows multiple moisture sensors.

A little code cleanup needed:
Introduce constants for pumpOn = GPIO.HIGH and pumpOff = GPIO.LOW for clarity and to easily change if the relay is on low and off high.

Ln 
 6   init = false                          # variable init never used or changed 
43  def pump_on(pump_pin = 7, delay = 1):  # parameter delay is never used