Published November 10, 2025

Home Automation: Plant Health Notifier

Updates soil status of connected plant every morning, and notifies whenever soil moisture falls below a threshold via a Discord webhook.

BeginnerShowcase (no instructions)3 hours118

Things used in this project

Hardware components

Particle Photon 2

Breadboard (generic)

Micro-USB to USB Cable (Generic)

Jumper wires (generic)

Male/Female Jumper Wires

Tactile Switch, Top Actuated

DFRobot Gravity: Analog Capacitive Soil Moisture Sensor- Corrosion Resistant

Software apps and online services

Particle Build Web IDE

Discord

Story

As someone who often forgets to water my own plants, I designed this project to remind me to do so based on the moisture content of my plants to ensure that they stay healthy. As someone who utilizes Discord very often, choosing to notify myself on this specific platform would make this device effective in remind myself.

Additionally, seeing automated bots in the countless Discord servers I have interacted in made me want to learn about the Discord API and how these bots are made. I had always found creating one very daunting, but after the webhook exercises in my Physical Computing Lab class, I found it more approachable and with some research, I was able to design a functional Discord webhook that would also be beneficial towards my everyday life. I found the process very fulfilling and enlightening since I was able to achieve a goal that I have always wanted to pursue but never found the confidence to do so.

1 / 3 • Discord channel that webhook is connected to and where updates are sent.

Code

Home Automation: Plant Health Notifier

At a set time every day, the user is notified of the status of their plant. Using the analog value retrieved by a soil moisture sensor that is inserted in the soil of a plant, my code maps gets the percent value (out of 100) of the moisture in the plants' soil. After that, it determines the status of the plant soil by assigning a status (Overwatered, Healthy, Needs water soon, and Needs water now) to the plant based on the percent moisture.

Additionally, when the moisture level drops below a healthy range, the user is automatically notified and is told to water their plant.

Finally, the final section of code allows me to send the notifier messages into discord with the press of a button, allowing me to test changes in my code without having to wait for the schedules sending times or for the moisture to dip below a threshold.

#include <stdio.h>

int analogPin = A5; // potentiometer connected to analog pin A5
int val = 0; // value
int button = 5; // button digital pin
int count = 0; // for button tracking
int color = 0;
String status;
bool warningSent = false;
bool secondWarningSent = false;

void setup()
{
    pinMode(button, INPUT_PULLUP);
    Serial.begin(9600);
    Time.zone(-6);
    delay(1000);
    
}

void loop()
{
    // tell time
    int hour = Time.hour();
    int minute = Time.minute();
    
    //get moisture reading
	val = analogRead(analogPin);
	val = map(val, 0, 4095, 0, 100);
	
	// determine status
	// if moisture is 50-100 its overwatered
	// if moisture is 30-49 it's healthy
	// if moisture is 20-39 it needs water soon
	// if moisture is 0-19 it is wilting
	if (val >= 50)
	{
	    status = "Overwatered";
	    color = 5191211;
	} else if ( val >= 30)
	{
	    status = "Healthy";
	    color = 4518529;
	} else if ( val >= 20)
	{
	    status = "Needs water soon";
	    color = 14603927;
	} else
	{
	    status = "Needs water now";
	    color = 9846591;
	}

    String tooLowData = String::format("{\"val\":\"%d\",\"status\":\"%s\",\"color\":%d}",val, status.c_str(), color);
    
    // sending if needs water soon
    if (val < 30 && val >= 20)
    {
        if (!warningSent){
            Particle.publish("tooLow", tooLowData, PRIVATE);
            warningSent = true;
        }
    } else if (val < 20)
    {
        if(!secondWarningSent){
            Particle.publish("tooLow", tooLowData, PRIVATE);
            secondWarningSent = true;
        }
    } else if (val >= 30)
    {
        warningSent = false;
        secondWarningSent = false;
    }
    
    String statusData = String::format("{\"val\":%d,\"status\":\"%s\",\"color\":%d}", val, status.c_str(), color);
    
    // status code
    if ((hour == 18 && minute == 3))
    {
        Particle.publish("statusUpdate", statusData, PRIVATE);
        delay(61000);
    }
    
    // Testing webhooks with button
  	int btnState = digitalRead(button);
	if ( btnState == LOW && count == 0)
	{
        Particle.publish("statusUpdate", statusData, PRIVATE);
        delay(1000);
        count++;
	} else if ( btnState == LOW && count == 1 )
	{
        Particle.publish("tooLow", tooLowData, PRIVATE);
        delay(1000);
        count--;
	}
}

{
  "embeds": [
    {
      "title": "**⚠️ Moisture Threshold Triggered! 🌾**",
      "description": "Moisture Level: **{{val}}%**\nStatus: **{{status}}**",
      "color": {{color}},
      "footer": {
        "text": "Automatic Alert"
      },
      "timestamp": "{{PARTICLE_PUBLISHED_AT}}"
    }
  ]
}

{
  "embeds": [
    {
      "title": "**Daily Plant Health Status 🌞🌱**",
      "description": "Soil moisture: **{{val}}%**\nStatus: **{{status}}**",
      "color": {{color}},
      "image": {
        "url": "https://img.freepik.com/free-vector/plant-growing_78370-263.jpg"
      },
      "timestamp": "{{PARTICLE_PUBLISHED_AT}}"
    }
  ]
}