// Arduino Button and LED Test using FreeRTOS // Copyright (C)2026, Philip Munts dba Munts Technologies. // // Redistribution and use in source and binary forms, with or without // modification, are permitted provided that the following conditions are met: // // * Redistributions of source code must retain the above copyright notice, // this list of conditions and the following disclaimer. // // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" // AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE // IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE // ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE // LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR // CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF // SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS // INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN // CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) // ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE // POSSIBILITY OF SUCH DAMAGE. #define ENABLE_FREERTOS #include QueueHandle_t EdgeQueue; // Button Interrupt Service Routine -- Enqueue button transitions void EdgeHandler(void) { bool newstate = digitalRead(BUTTON ^ BUTTON_XOR); xQueueSendFromISR(EdgeQueue, &newstate, NULL); } // Main task -- Dequeue button transitions and display results void MainTaskFunction(void *parameters) { // Attach button GPIO pin interrupt service routine attachInterrupt(digitalPinToInterrupt(BUTTON), EdgeHandler, CHANGE); // Main event loop for (;;) { bool newstate; if (xQueueReceive(EdgeQueue, &newstate, pdMS_TO_TICKS(1000)) == pdPASS) { Serial.println(newstate ? "PRESS" : "RELEASE"); digitalWrite(LED, newstate); } else Serial.println("Tick..."); } } void setup() { Serial.begin(115200); Serial.println("\n\n\ecArduino Button and LED Test using FreeRTOS\n"); Serial.print("LED on D"); Serial.println(LED); Serial.print("Button on D"); Serial.println(BUTTON); Serial.println(); pinMode(BUTTON, BUTTON_PINMODE); pinMode(LED, OUTPUT); digitalWrite(LED, digitalRead(BUTTON) ^ BUTTON_XOR); // Create FreeRTOS entities and start the scheduler EdgeQueue = xQueueCreate(10, sizeof(bool)); xTaskCreate(MainTaskFunction, "main", 512, NULL, 1, NULL); vTaskStartScheduler(); } void loop() { }