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Queue Communication not working

Posted by rclub123 on October 4, 2016

Hi i am trying to send an array from one task to another task.. but it is not working. here is my pseudo code: ~~~ int main(void) { xQueue = xQueueCreate( 2, sizeof(unsigned int) ); if ((xTaskCreate(vTask0, (const char )"Task0", configMINIMALSTACKSIZE, NULL, tskIDLEPRIORITY+2, &xHandle) != pdPASS) || (xTaskCreate(vTask1, (const char *)"Task1", configMINIMALSTACKSIZE, NULL, tskIDLEPRIORITY+2, &xHandle1) != pdPASS)) { printf("xTaskCreate() failed to create a task.n"); } else { / Start scheduler */ printf("Starting scheduler.n"); vTaskStartScheduler(); } } ~~~

~~~ void vTask0(void *pvParameters) { TickTypet xNextWakeTime; unsigned int data[2]; uint16t samplecount = 0; const TickTypet xFrequency =10; xNextWakeTime = xTaskGetTickCount(); while(1) { if (xQueueReceive(xQueue, &data,(portTickType)2)) { printf("received = %d n", data[0]); printf("received1 = %d n", data[1]); } vTaskDelayUntil(&xNextWakeTime, xFrequency); } } ~~~ ~~~ void vTask1(void *pvParameters) { TickTypet xNextWakeTime; unsigned int data[2]; const TickType_t xFrequency = 10; xNextWakeTime = xTaskGetTickCount(); while(1) { data[0]=3; data[1]=4; xQueueSendToBack(xQueue, &data, 0); vTaskDelayUntil(&xNextWakeTime, xFrequency); } } ~~~ Sorry i am new to RTOS, i want to send both data[0] and [1] to another task.. if i change the priority it will receive some random number. can anyone tell me what mistake i have done?


Queue Communication not working

Posted by davedoors on October 4, 2016

xQueueCreate( 2, sizeof(unsigned int) );

This creates a queue where each space can hold 1 unsigned int, so

xQueueSendToBack(xQueue, &data, 0);

sends one unsigned int, not two. Plus you are sending the address of the array not the array contents. Change '&data' to just 'data' in both the xQueueReceive and xQueueSendToBack calls.


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