Week 12: UI

Can I make my plants less thirsty? Part 2

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This week, our assignment was to create a user interface to interact with one of our input or output devices. I decided to build off of last week’s assignment and make a web interface for the soil moisture sensor.

For this assignment, I used Google’s handy firebase to store the data that the Xiao ESP32-C6 read. Firebase also created an easy way to build a web interface to see the data being read.

import network
import urequests
import time
from machine import Pin, ADC
import random

# Wi-Fi credentials
WIFI_SSID = "MIT 2"
WIFI_PASSWORD = "***"

# Firebase credentials
API_KEY = "**"
DATABASE_URL = "***"  # Without "https://"

# Global variables
last_send_time = 0
count = 0

def connect_to_wifi():
    wlan = network.WLAN(network.STA_IF)
    wlan.active(True)
    wlan.connect(WIFI_SSID, WIFI_PASSWORD)
    print("Connecting to Wi-Fi", end="")
    while not wlan.isconnected():
        print(".", end="")
        time.sleep(0.3)
    print("\nConnected with IP:", wlan.ifconfig()[0])

def write_firebase_data(path, value):
    url = f"https://{DATABASE_URL}/{path}.json?auth={API_KEY}"
    try:
        response = urequests.put(url, json=value)
        if response.status_code == 200:
            print(f"PASSED: {path}")
        else:
            print(f"FAILED: {path} - {response.status_code}: {response.text}")
    except Exception as e:
        print(f"Error writing to Firebase: {str(e)}")

def main():
    global last_send_time, count
    soil_in = ADC(0)
    moisture = soil_in.read_u16() / 65535.0
    connect_to_wifi()

    while True:
        
        current_time = time.ticks_ms()
        if time.ticks_diff(current_time, last_send_time) > 15000:
            
            soil_in = ADC(0)
            moisture = soil_in.read_u16() / 65535.0
            last_send_time = current_time

            # Write an integer to the database path "test/int"
            write_firebase_data("test/int", count)
            count += 1

            # Write a float to the database path "test/float"
            float_value = round(0.01 + random.randint(0, 100), 2)
            write_firebase_data("test/float", moisture)
            write_firebase_data("test/float", float_value)

            print("---")

if __name__ == "__main__":
    main()

I then used raw HTML to create a simple user interface to read out the data from the moisture sensor, using the firebase authentication keys.