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xSerialPutChar problem

Posted by Nobody/Anonymous on March 6, 2007
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.


Sohn, Seoul, Korea

static void vTest( void *pvParameters )
for( ;; )

vTaskDelay( 900);
xSerialPutChar( NULL, 'A', 100 );
vTaskDelay( 100);


RE: xSerialPutChar problem

Posted by Nobody/Anonymous on March 6, 2007
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.


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