I have a problem with serial communication. I made a simple task that send ‘A’ once per second (PIC18F4550 with MPLAB C 7.52) On Window’s Hyperterminal, ‘A’ appears once per 5 seconds. I suspect queue caused the trouble(I declared serial queue length  to 5 )             #define mainCOMMS_QUEUE_LENGTH            ( 5 ) Please tell me what’s wrong. Regards Sohn, Seoul, Korea static void vTest( void *pvParameters ) {     for( ;; )     {                 vTaskDelay( 900);         xSerialPutChar( NULL, ‘A’, 100 );         vParTestToggleLED(2);         vTaskDelay( 100);         vParTestToggleLED(2);     } }

From the code it looks like A should be sent every 1000 ticks, but there is nothing to say what one tick represents.  It could be that the tick is running 5 times slower than you think.  Most likely the thing that is wrong is the setup of the timer that is generating the tick. Check the configTICK_RATE_HZ and configCPU_CLOCK_HZ settings in FreeRTOSConfig.h along with prvSetupTimerInterrupt() in port.c.  If these are both right take a look at your initialization code to see how you are setting up the processor clock frequency. Dave.