Soil Humidity

🎮 Display the Raw Moisture Reading

Goal

Read the soil moisture sensor and display its raw analog value on the PC.

Concepts

Analog Input · ADC · Moisture · Loop · Serial Output

import machine  # Controls the board hardware
import time     # Controls pauses and timing

# Sets up GPIO2 as an analog input for the moisture sensor
# GPIO2 corresponds to A0 on the Sensor Shield V5.0
adc2 = machine.ADC(machine.Pin(2))

adc2.atten(machine.ADC.ATTN_11DB)  # Sets the analog input range

while True:  # Repeats forever

    moisture = adc2.read_u16()  # Reads the moisture value

    print(moisture)  # Sends the raw value to the PC

    time.sleep(0.5)  # Waits before reading again

🎮 Dry, Moist or Wet

Goal

Classify the soil reading as Dry, Moist, or Wet.

Concepts

Analog Input · Thresholds · If/Elif/Else · Classification · Serial Output

import machine  # Controls the board hardware
import time     # Controls pauses and timing

# Sets up GPIO2 as an analog input for the moisture sensor
# GPIO2 corresponds to A0 on the Sensor Shield V5.0
adc2 = machine.ADC(machine.Pin(2))

adc2.atten(machine.ADC.ATTN_11DB)  # Sets the analog input range

while True:  # Repeats forever

    moisture = adc2.read_u16()  # Reads the moisture value

    if moisture > 45000:  # Checks the dry range
        print('Dry')  # Reports dry soil

    elif moisture > 25000:  # Checks the moist range
        print('Moist')  # Reports moist soil

    else:  # Runs for the wet range
        print('Wet')  # Reports wet soil

    time.sleep(0.5)  # Waits before reading again

🎮 Detect Changes Between Moisture Ranges

Goal

Report when the soil changes between Dry, Moist, and Wet.

Concepts

Analog Input · Thresholds · Variables · State Change · Serial Output

import machine  # Controls the board hardware
import time     # Controls pauses and timing

# Sets up GPIO2 as an analog input for the moisture sensor
# GPIO2 corresponds to A0 on the Sensor Shield V5.0
adc2 = machine.ADC(machine.Pin(2))

adc2.atten(machine.ADC.ATTN_11DB)  # Sets the analog input range

last_state = ''  # Stores the previous moisture state

while True:  # Repeats forever

    moisture = adc2.read_u16()  # Reads the moisture value

    if moisture > 45000:  # Checks the dry range
        state = 'Dry'  # Saves the dry state

    elif moisture > 25000:  # Checks the moist range
        state = 'Moist'  # Saves the moist state

    else:  # Runs for the wet range
        state = 'Wet'  # Saves the wet state

    if state != last_state:  # Checks if the state changed

        print('Changed to:', state)  # Reports the new state

        last_state = state  # Saves the new state

    time.sleep(0.5)  # Waits before reading again

🎮 Track Moisture Changes Over Time

Goal

Compare each moisture reading with the previous reading and show whether the value increased, decreased, or stayed nearly the same.

Concepts

Analog Input · Variables · Comparison · Change Over Time · Serial Output

import machine  # Controls the board hardware
import time     # Controls pauses and timing

# Sets up GPIO2 as an analog input for the moisture sensor
# GPIO2 corresponds to A0 on the Sensor Shield V5.0
adc2 = machine.ADC(machine.Pin(2))

adc2.atten(machine.ADC.ATTN_11DB)  # Sets the analog input range

last_value = adc2.read_u16()  # Saves the first reading

while True:  # Repeats forever

    moisture = adc2.read_u16()  # Reads the current value

    change = moisture - last_value  # Calculates the change

    print('Reading:', moisture)  # Shows the current reading

    print('Change:', change)  # Shows the amount of change

    if change > 500:  # Checks for a clear increase
        print('Value increased')  # Reports the increase

    elif change < -500:  # Checks for a clear decrease
        print('Value decreased')  # Reports the decrease

    else:  # Runs when the change is small
        print('Almost no change')  # Reports a stable reading

    last_value = moisture  # Saves the current reading

    time.sleep(1)  # Waits before reading again

🎮 Soil Monitoring Report

Goal

Create a soil monitor that displays the current reading, moisture classification, change from the previous reading, and time spent in the current condition.

Concepts

Analog Input · Thresholds · Variables · Timing · State Change · Serial Output

import machine  # Controls the board hardware
import time     # Controls pauses and timing

# Sets up GPIO2 as an analog input for the moisture sensor
# GPIO2 corresponds to A0 on the Sensor Shield V5.0
adc2 = machine.ADC(machine.Pin(2))

adc2.atten(machine.ADC.ATTN_11DB)  # Sets the analog input range

last_value = adc2.read_u16()  # Saves the first reading

last_state = ''  # Stores the previous moisture state

start_time = time.ticks_ms()  # Saves the starting time

while True:  # Repeats forever

    moisture = adc2.read_u16()  # Reads the moisture value

    change = moisture - last_value  # Calculates the reading change

    if moisture > 45000:  # Checks the dry range
        state = 'Dry'  # Saves the dry state

    elif moisture > 25000:  # Checks the moist range
        state = 'Moist'  # Saves the moist state

    else:  # Runs for the wet range
        state = 'Wet'  # Saves the wet state

    if state != last_state:  # Checks if the condition changed

        start_time = time.ticks_ms()  # Starts timing the new condition

        last_state = state  # Saves the new condition

    time_in_state = time.ticks_diff(time.ticks_ms(), start_time)  # Gets time in this condition

    print('Reading:', moisture)  # Shows the current reading

    print('Condition:', state)  # Shows Dry, Moist or Wet

    print('Change:', change)  # Shows the reading change

    print('Time:', time_in_state, 'ms')  # Shows time in this condition

    print('---')  # Separates each report

    last_value = moisture  # Saves the current reading

    time.sleep(1)  # Waits before reading again