MatterRainSensor
About
The MatterRainSensor class provides a rain sensor endpoint for Matter networks. This endpoint implements the Matter rain sensing standard for detecting rain presence (detected/not detected states).
Features: * Rain detection state reporting (detected/not detected) * Simple boolean state * Read-only sensor (no control functionality) * Automatic state updates * Integration with Apple HomeKit, Amazon Alexa, and Google Home * Matter standard compliance
Use Cases: * Weather monitoring systems * Irrigation control systems * Outdoor sensor networks * Smart home automation triggers * Rain detection for automated systems
API Reference
Constructor
MatterRainSensor
Creates a new Matter rain sensor endpoint.
MatterRainSensor();
Initialization
begin
Initializes the Matter rain sensor endpoint with an initial rain detection state.
bool begin(bool _rainState = false);
_rainState- Initial rain detection state (true= detected,false= not detected, default:false)
This function will return true if successful, false otherwise.
end
Stops processing Matter rain sensor events.
void end();
Rain Detection State Control
setRain
Sets the rain detection state.
bool setRain(bool _rainState);
_rainState- Rain detection state (true= detected,false= not detected)
This function will return true if successful, false otherwise.
getRain
Gets the current rain detection state.
bool getRain();
This function will return true if rain is detected, false if not detected.
Operators
bool operator
Returns the current rain detection state.
operator bool();
Example:
if (mySensor) {
Serial.println("Rain is detected");
} else {
Serial.println("Rain is not detected");
}
Assignment operator
Sets the rain detection state.
void operator=(bool _rainState);
Example:
mySensor = true; // Set rain detection to detected
mySensor = false; // Set rain detection to not detected
Example
Rain Sensor
// Copyright 2025 Espressif Systems (Shanghai) PTE LTD
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
/*
* This example is an example code that will create a Matter Device which can be
* commissioned and controlled from a Matter Environment APP.
* Additionally the ESP32 will send debug messages indicating the Matter activity.
* Turning DEBUG Level ON may be useful to following Matter Accessory and Controller messages.
*
* The example will create a Matter Rain Sensor Device.
* The Rain Sensor state can be toggled by pressing the onboard button.
* The Rain Sensor state will be indicated by the onboard LED.
* The Rain Sensor state will be simulated to change every 20 seconds.
*
* The onboard button can be kept pressed for 5 seconds to decommission the Matter Node.
* The example will also show the manual commissioning code and QR code to be used in the Matter environment.
*
*/
// Matter Manager
#include <Matter.h>
#if !CONFIG_ENABLE_CHIPOBLE
// if the device can be commissioned using BLE, WiFi is not used - save flash space
#include <WiFi.h>
#endif
// List of Matter Endpoints for this Node
// Matter Rain Sensor Endpoint
MatterRainSensor RainSensor;
// CONFIG_ENABLE_CHIPOBLE is enabled when BLE is used to commission the Matter Network
#if !CONFIG_ENABLE_CHIPOBLE
// WiFi is manually set and started
const char *ssid = "your-ssid"; // Change this to your WiFi SSID
const char *password = "your-password"; // Change this to your WiFi password
#endif
// LED will be used to indicate the Rain Sensor state
// set your board RGB LED pin here
#ifdef RGB_BUILTIN
const uint8_t ledPin = RGB_BUILTIN;
#else
const uint8_t ledPin = 2; // Set your pin here if your board has not defined LED_BUILTIN
#warning "Do not forget to set the RGB LED pin"
#endif
// set your board USER BUTTON pin here - decommissioning and Manual Rain Sensor toggle button
const uint8_t buttonPin = BOOT_PIN; // Set your pin here. Using BOOT Button.
// Button control
uint32_t button_time_stamp = 0; // debouncing control
bool button_state = false; // false = released | true = pressed
const uint32_t debouceTime = 250; // button debouncing time (ms)
const uint32_t decommissioningTimeout = 5000; // keep the button pressed for 5s, or longer, to decommission
void setup() {
// Initialize the USER BUTTON (Boot button) that will be used to decommission the Matter Node
// The button will also be used to manually toggle the Rain Sensor state
pinMode(buttonPin, INPUT_PULLUP);
// Initialize the LED (light) GPIO and Matter End Point
pinMode(ledPin, OUTPUT);
Serial.begin(115200);
// CONFIG_ENABLE_CHIPOBLE is enabled when BLE is used to commission the Matter Network
#if !CONFIG_ENABLE_CHIPOBLE
// Manually connect to WiFi
WiFi.begin(ssid, password);
// Wait for connection
while (WiFi.status() != WL_CONNECTED) {
delay(500);
Serial.print(".");
}
Serial.println();
#endif
// set initial rain sensor state as false (default)
RainSensor.begin();
digitalWrite(ledPin, LOW); // LED OFF
// Matter beginning - Last step, after all EndPoints are initialized
Matter.begin();
// Check Matter Accessory Commissioning state, which may change during execution of loop()
if (!Matter.isDeviceCommissioned()) {
Serial.println("");
Serial.println("Matter Node is not commissioned yet.");
Serial.println("Initiate the device discovery in your Matter environment.");
Serial.println("Commission it to your Matter hub with the manual pairing code or QR code");
Serial.printf("Manual pairing code: %s\r\n", Matter.getManualPairingCode().c_str());
Serial.printf("QR code URL: %s\r\n", Matter.getOnboardingQRCodeUrl().c_str());
// waits for Matter Rain Sensor Commissioning.
uint32_t timeCount = 0;
while (!Matter.isDeviceCommissioned()) {
delay(100);
if ((timeCount++ % 50) == 0) { // 50*100ms = 5 sec
Serial.println("Matter Node not commissioned yet. Waiting for commissioning.");
}
}
Serial.println("Matter Node is commissioned and connected to the network. Ready for use.");
}
}
bool simulatedHWRainSensor() {
// Simulated Rain Sensor
static bool rainState = false;
static uint32_t lastTime = 0;
// Simulate a Rain Sensor state change every 20 seconds
if (millis() - lastTime > 20000) {
rainState = !rainState;
lastTime = millis();
}
return rainState;
}
void loop() {
// Check if the button has been pressed
if (digitalRead(buttonPin) == LOW && !button_state) {
// deals with button debouncing
button_time_stamp = millis(); // record the time while the button is pressed.
button_state = true; // pressed.
}
uint32_t time_diff = millis() - button_time_stamp;
if (button_state && time_diff > debouceTime && digitalRead(buttonPin) == HIGH) {
button_state = false; // released
// button is released - toggle Rain State (Not Detected/Detected)
RainSensor.setRain(!RainSensor.getRain()); // same as RainSensor = !RainSensor;
Serial.printf("User button released. Setting the Rain Sensor to %s.\r\n", RainSensor ? "Detected" : "Not Detected");
// LED will indicate the Rain Sensor state
if (RainSensor) {
digitalWrite(ledPin, HIGH); // LED ON
} else {
digitalWrite(ledPin, LOW); // LED OFF
}
}
// Onboard User Button is kept pressed for longer than 5 seconds in order to decommission matter node
if (button_state && time_diff > decommissioningTimeout) {
Serial.println("Decommissioning Rain Sensor Matter Accessory. It shall be commissioned again.");
Matter.decommission();
button_time_stamp = millis(); // avoid running decommissining again, reboot takes a second or so
}
// Simulated Rain Sensor
RainSensor.setRain(simulatedHWRainSensor());
delay(50);
}