Differences

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--- en-us_commands:reference:itimerstate [2026/09/07 23:35] – 바깥 편집 127.0.0.1
+++ en-us_commands:reference:itimerstate [2026/09/12 22:54] (current) – 바깥 편집 127.0.0.1
@@ Line 15: / Line 15: @@
 ===== Example =====
+This uses the default callback timer (Timer2). The callback changes only a flag; serial output runs in ''loop()''.
 <code cpp>
-const uint8_t CALLBACK_TIMER = 3;
+void onTimer() {}
-volatile bool sampleDue = false;
-void sampleTask() {
-  sampleDue = true;
-}
 void setup() {
   Serial.begin(115200);
-  if (!ItimerSet(CALLBACK_TIMER, 100, sampleTask)) {  // Set the interval and callback function, or select the hardware timer to use.
+  if (!ItimerSet(1000, onTimer)) return;  // Configure the callback and interval first.
-    Serial.println(F("timer setup failed"));
+  ItimerStart();  // Start the configured callback timer.
-    return;
-  }
-  ItimerStart(CALLBACK_TIMER);  // Start the configured callback timer.
 }
 void loop() {
-  if (sampleDue) {
+  static unsigned long lastPrint = 0;
-    noInterrupts();
+  static bool stopped = false;
-    sampleDue = false;
+  if (!stopped && millis() >= 3000) {
-    interrupts();
+    ItimerStop();  // Stop the default callback timer after 5 s.
-    Serial.println(analogRead(A0));  // Read the raw analog value of the specified channel.
+    stopped = true;
+  }
+  if (millis() - lastPrint >= 1000) {
+    lastPrint = millis();
+    const bool running = ItimerState();  // Check whether the default callback timer is running.
+    Serial.println(running ? F("running") : F("stopped"));
   }
-  const bool pause = IdigitalRead(0, 5);  // Read the input repeatedly and update only if all samples match. If HIGH and LOW are mixed, retain the previous stable state.
-  if (pause && ItimerState(CALLBACK_TIMER)) ItimerStop(CALLBACK_TIMER);  // Return the running state of the default or specified callback timer. / Stop the default or specified callback timer.
-  if (!pause && !ItimerState(CALLBACK_TIMER)) ItimerStart(CALLBACK_TIMER);  // Start the configured callback timer. / Return the running state of the default or specified callback timer.
-  if (IdigitalRead(1, 5)) ItimerStopAll();  // Stop all running callback timers. / Read the input repeatedly and update only if all samples match. If HIGH and LOW are mixed, retain the previous stable state.
 }
 </code>
@@ Line 50: / Line 44: @@
 ===== Precautions =====
-  * Timer interrupt callbacks run inside an ISR. For safety, change only flags in the callback and perform actual control processing in ''loop()''.
+  * The callback runs in an interrupt. Change only a flag there; do not call ''delay()'', ''Serial'', I2C or SPI in it.
-  * Do not use slow or interrupt-dependent code such as ''delay()'', ''Serial'', I2C or SPI in callbacks.
+  * The callback timer without a timer number uses Timer2. Do not use it together with ''tone()'' or PWM output that uses Timer2.
-  * Normally, call ''ImodbusRTU()'' repeatedly in ''loop()''. Call it from a timer interrupt with a sufficient interval only when long ''delay()'' calls or debug output slow down ''loop()''.
+  * When specifying another hardware timer, check for conflicts with PWM, analog output and high-speed counter functions using it.
-  * Do not use the default ''ItimerSet()'' together with ''tone()'' using Timer2 or ''analogWrite()'' on Timer2 PWM pins.
-  * Explicitly using Timer1, Timer3, Timer4 or Timer5 may conflict with PWM, analog output or high-speed counter functions using that timer.
+===== Built-in Commands in the Same Category =====
-  * Configure only one ''Itimer'' callback per hardware timer.
-  * Defining an ISR for the same timer directly in the sketch may conflict with ''Itimer'' operation.
+  * [[:en-us_commands:reference:itimerset|ItimerSet() View detailed description]]
-  * ''ItimerStopAll()'' stops only hardware interrupt timers. It does not reset PLC-style timer states such as ''Iton'', ''Itof'' or ''Itmr''.
+  * [[:en-us_commands:reference:itimerstart|ItimerStart() View detailed description]]
+  * [[:en-us_commands:reference:itimerstop|ItimerStop() View detailed description]]
+  * [[:en-us_commands:reference:itimerstopall|ItimerStopAll() View detailed description]]
 [[:en-us_commands:builtin|← Built-in Command List]]