More examples

Author: zekageri

CHANGELOG.md

@@ -3,7 +3,9 @@
 All notable changes to this project will be documented in this file.
 
 ## [Unreleased]
-- No changes yet.
+### Added
+- `examples/manual_sampling` shows manual `sampleNow()` usage without the esp_timer while keeping calibration/history stable.
+- `examples/json_export` streams newline-delimited JSON via `toJson()` + ArduinoJson for telemetry pipelines.
 
 ## [1.0.1] - 2025-12-03
 ### Fixed

README.md

@@ -16,6 +16,10 @@ ESPCpuMonitor is a tiny C++17 helper that estimates per-core CPU usage on ESP32
 - Optional ArduinoJson export helper to stream samples over HTTP/MQTT/WebSockets alongside the rest of ESPToolKit.
 
 ## Examples
+- `examples/basic_monitor` – timer-driven sampling with per-core logs and optional temperature readings.
+- `examples/manual_sampling` – drives `sampleNow()` manually (no esp_timer), shows how to log history depth and keep calibration/averaging stable during bursty work.
+- `examples/json_export` – streams newline-delimited JSON via `toJson()` + ArduinoJson for dashboards/MQTT/serial telemetry.
+
 Basic Arduino sketch that prints CPU usage once calibrated:
 
 ```cpp
@@ -89,7 +93,7 @@ If temperature is enabled, `getLastTemperature(current, average)` returns the la
 - C++17 required; tested with dual-core chips but handles `portNUM_PROCESSORS == 1`.
 
 ## Tests
-- Build and run `examples/basic_monitor` via PlatformIO CI or Arduino CLI for a quick smoke test on ESP32 dev boards.
+- Build and run `examples/basic_monitor`, `examples/manual_sampling`, and `examples/json_export` via PlatformIO CI or Arduino CLI for a quick smoke test on ESP32 dev boards.
 
 ## License
 MIT — see [LICENSE.md](LICENSE.md).

examples/json_export/json_export.ino

@@ -0,0 +1,48 @@
+#include <Arduino.h>
+#include <ESPCpuMonitor.h>
+
+#if !ESPCM_HAS_ARDUINOJSON
+#error "Install ArduinoJson to run this example."
+#endif
+
+#include <ArduinoJson.h>
+#include <cmath>
+
+static const uint32_t HISTORY_LOG_PERIOD_MS = 5000;
+
+void setup() {
+    Serial.begin(115200);
+
+    CpuMonitorConfig cfg;
+    cfg.sampleIntervalMs = 1000; // 1s cadence for telemetry
+    cfg.historySize = 12;        // keep a handful of points for charts/debug
+    cfg.enableTemperature = true;
+    cpuMonitor.init(cfg);
+
+    cpuMonitor.onSample([](const CpuUsageSample &sample) {
+        StaticJsonDocument<256> doc;
+        cpuMonitor.toJson(sample, doc);
+        doc["avgRounded"] = static_cast<int>(roundf(sample.average)); // handy for dashboards
+
+        serializeJson(doc, Serial);
+        Serial.println(); // newline-delimited JSON (NDJSON) stream
+    });
+}
+
+void loop() {
+    static uint32_t lastHistoryMs = 0;
+
+    if (cpuMonitor.isReady() && millis() - lastHistoryMs >= HISTORY_LOG_PERIOD_MS) {
+        lastHistoryMs = millis();
+        const auto hist = cpuMonitor.history();
+        if (!hist.empty()) {
+            const auto &latest = hist.back();
+            Serial.printf("[json_export] history_depth=%u last_avg=%.1f%% last_temp=%.1fC\n",
+                          static_cast<unsigned>(hist.size()),
+                          latest.average,
+                          std::isnan(latest.temperatureC) ? -1.0f : latest.temperatureC);
+        }
+    }
+
+    delay(50);
+}

examples/json_export/platformio.ini

@@ -0,0 +1,9 @@
+[env:esp32dev]
+platform = espressif32
+board = esp32dev
+framework = arduino
+monitor_speed = 115200
+
+lib_deps =
+    ArduinoJson @ ^7
+    ESPCpuMonitor

examples/manual_sampling/manual_sampling.ino

@@ -0,0 +1,57 @@
+#include <Arduino.h>
+#include <ESPCpuMonitor.h>
+#include <esp_log.h>
+
+static const uint32_t SAMPLE_PERIOD_MS = 500;
+
+// Simple spin to create a small CPU bump for the manual sampler.
+static void spinWork(uint32_t durationMicros) {
+    const uint32_t start = micros();
+    while ((uint32_t)(micros() - start) < durationMicros) {
+        asm volatile("nop");
+    }
+}
+
+void setup() {
+    Serial.begin(115200);
+
+    CpuMonitorConfig cfg;
+    cfg.sampleIntervalMs = 0;      // manual sampling only
+    cfg.calibrationSamples = 8;    // give the idle baseline a few readings
+    cfg.historySize = 10;
+    cfg.enablePerCore = false;     // focus on averaged load
+    cfg.enableTemperature = false; // keep it portable on targets without temp sensor
+    cpuMonitor.init(cfg);
+
+    cpuMonitor.onSample([](const CpuUsageSample &sample) {
+        ESP_LOGI("CPU", "avg=%.1f%% ts=%llu",
+                 sample.average,
+                 static_cast<unsigned long long>(sample.timestampUs));
+    });
+}
+
+void loop() {
+    static uint32_t lastSampleMs = 0;
+
+    // Simulate bursty work after calibration: spin for ~5ms while in a "busy" window.
+    const bool busyWindow = cpuMonitor.isReady() && (millis() / 3000) % 2 == 0;
+    if (busyWindow) {
+        spinWork(5000);
+    }
+
+    if (millis() - lastSampleMs >= SAMPLE_PERIOD_MS) {
+        lastSampleMs = millis();
+
+        CpuUsageSample sample{};
+        bool ready = cpuMonitor.sampleNow(sample); // drive sampling yourself
+        if (!ready) {
+            Serial.println("[manual_sampling] calibrating baseline...");
+        } else {
+            Serial.printf("[manual_sampling] avg=%.1f%% history_depth=%u\n",
+                          sample.average,
+                          static_cast<unsigned>(cpuMonitor.history().size()));
+        }
+    }
+
+    delay(10);
+}

examples/manual_sampling/platformio.ini

@@ -0,0 +1,9 @@
+[env:esp32dev]
+platform = espressif32
+board = esp32dev
+framework = arduino
+monitor_speed = 115200
+
+lib_deps =
+    ArduinoJson @ ^7
+    ESPCpuMonitor