Don't forget to actually add the example ;-)

timkoers · timkoers · commit b3511e5de285 · 2021-01-17T12:27:07.000+01:00
diff --git a/libraries/ESP32/examples/Serial/InterruptQueue/InterruptQueue.ino b/libraries/ESP32/examples/Serial/InterruptQueue/InterruptQueue.ino
@@ -0,0 +1,59 @@
+/** Tim Koers - 2021
+  *
+  * This sketch shows the usage of an queue, to store and read the characters that are sent to the interrupt.
+  * You can safely use this in a FreeRTOS environment and use the queue from different tasks on different CPU cores.
+  * This sketch assumes that when Hi is sent, the device returns an 8 byte message.
+  * 
+  */
+
+#define BUFFER_SIZE 8
+
+// This queue is here to handle the interruption of the loop when the interrupt is running.
+Queue_t bufferQueue;
+
+bool messageSent = false;
+
+// Please keep in mind, since the ESP32 is dual core, 
+// the interrupt will be running on the same core as the setRxInterrupt function was called on.
+static void IRAM_ATTR onSerialRX(uint8_t character, void* user_arg){
+	
+	BaseType_t xHighPriorityTaskWoken;
+	
+	if(!xQueueSendFromISR(bufferQueue, &character, &xHighPriorityTaskWoken) == pdTRUE){
+	  log_e("IRQ", "Failed to put character onto the queue\n");
+	}
+}
+
+void setup()
+{
+  bufferQueue = xQueueCreate(BUFFER_SIZE * 4, sizeof(char)); // Create a queue that can hold 4 messages of 8-bytes each.
+	
+  assert(bufferQueue != NULL);
+
+  Serial.begin(115200);
+  Serial2.begin(115200);
+
+  Serial2.setRxInterrupt(onSerialRX, NULL);
+}
+
+void loop()
+{
+  if(!messageSent){
+	  Serial.println("Hi");
+	  messageSent = true;
+  }
+
+  // Check if data in the queue and check if there is a complete message (8-bytes) in the queue
+  if(!(uxQueueMessagesWaiting(bufferQueue) % RESPONSE_SIZE)){
+    char c;
+	// Check if the queue is not empty, 0 % 8 returns 0 instead, so does 24 % 8
+	while(uxQueueMessagesWaiting(bufferQueue) > 0){
+	  // Get the character from the queue, but don't block if someone else is busy with the queue
+	  if(xQueueReceive(bufferQueue, &c, 0) == pdTRUE)
+		Serial.write(c);
+	}
+	
+	// Allow the system to request another data set
+	messageSent = false;
+  }
+}
