Metrics Example¶

/**
 * SPDX-FileCopyrightText: 2026 Maximiliano Ramirez <maximiliano.ramirezbravo@gmail.com>
 *
 * SPDX-License-Identifier: MIT
 */

/**
 * ReactiveESP32 Example Overview:
 * - This example demonstrates the usage of the Node Metrics feature.
 * - A Signal and a Computed node are created, both named for easier identification.
 * - After setting the signal multiple times, the metrics for both nodes can be printed.
 *
 * - It's necessary to have RXESP32_ENABLE_NODE_METRICS enabled in the configuration.
 *
 * - The Serial interface is used to interact with the program:
 *   - 's': Set the signal to new random values multiple times.
 *   - 'g': Get the current value of the signal and computed.
 *   - 'i': Print general node statistics.
 *   - 'p': Print the metrics for the signal and computed nodes.
 *
 * - Pressing '0' restarts the ESP32.
 */

#include <ReactiveESP32.h>
using namespace RxESP32;

#if RXESP32_ENABLE_NODE_METRICS == 0
#error "This example requires RXESP32_ENABLE_NODE_METRICS to be enabled"
#else

/* ---------------------------------------------------------------------------------------------- */
// Define a simple signal
Signal<uint8_t> number(0, {.name = "Number Signal"});

// Define a computed value that doubles the signal
Computed<uint16_t> doubled(
  []() {
    uint16_t value = number.get() * 2;
    return value;
  },
  {.name = "Doubled Computed"});

// Read Serial input and process commands
void serialRead();
/* ---------------------------------------------------------------------------------------------- */

void setup() {
  Serial.begin(115200);
  delay(1000);

  Serial.println("===============================");
  Serial.println("ReactiveESP32 - Metrics Example");
  Serial.println("===============================");

  // Start the ReactiveESP32 dispatcher
  if (!Dispatcher::start()) {
    Serial.println("Failed to start ReactiveESP32 Dispatcher!");
    while (true) {
      delay(1000);
    }
  }
}

void loop() { serialRead(); }

void serialRead() {
  if (!Serial.available()) return;

  char c = Serial.read();

  if (c == '\r') return;
  if (c == '\n') c = ' ';
  Serial.printf("> %c\n", c);

  switch (c) {
    case '0':
    {
      // Restart the ESP32
      ESP.restart();
    } break;

    case 's':
    {
      // Set the signal to a random value between 0 and 100
      // 10 times with a 10ms delay between sets
      for (int i = 0; i < 10; i++) {
        uint8_t new_value = random(0, 101);
        Serial.printf("Setting 'number' signal to: %u\n", new_value);
        number.set(new_value);
        delay(10);
      }
    } break;

    case 'g':
    {
      // Get the current value of signal and computed
      uint8_t value_number   = number.get();
      uint16_t value_doubled = doubled.get();
      Serial.printf("Number - Doubled: %u - %u\n", value_number, value_doubled);
    } break;

    case 'i':
    {
      // Print node stats to Serial
      Utils::printNodeStats();
    } break;

    case 'p':
    {
      // Print metrics of signal and computed
      Utils::printNodeMetrics(number);
      Utils::printNodeMetrics(doubled);
    } break;
  }
}

#endif