bull98 wrote on Monday, November 05, 2012:
Hello, I have created a project that was started from the PIC32 UART driver demo. I started out with a simple task that ran periodically and successfully wrote to the UART. I then modified the task so that it uses a queue to get a message and then access the UART. Now it gets thrown into the general exception handler any time it calls any of the functions in the UART driver.
I have tried re-initializing the UART after the queue receive. I am really struggling to understand why I can talk to the UART before the block and wait for queue, but not after. Can anyone please shed some light on what may be going wrong here?
Thank you in advance, I am about 18 hours in to debugging this with no progress
Setup:
Processor: PIC32MX795F512L
Dev Board: PIC32 USB Starter Kit II
Compiler: C32
FreeRTOS version: 7.2
Here is the code:
#define UART_STACK_SIZE configMINIMAL_STACK_SIZE
#define YIELDING_TIME_UART ( 10 / portTICK_RATE_MS ) //5ms
#define SIZE_OF_BUFFER_IN 63
#define SIZE_OF_BUFFER_OUT (SIZE_OF_BUFFER_IN *50)+1
// ----------------------------------------------
// FUNCTION DECLARATIONS
// ----------------------------------------------
static portTASK_FUNCTION_PROTO( vSerialTestTask, pvParameters );
// ----------------------------------------------
// GLOBAL VARIABLES
// ----------------------------------------------
xTaskHandle* handle;
static char buffer_in[SIZE_OF_BUFFER_IN];
static char buffer_out[SIZE_OF_BUFFER_OUT];
static char second_buffer_out[SIZE_OF_BUFFER_OUT];
static int position = 0;
static int cr_received;
xQueueHandle xQueueHandleGSMSend2;
LogMessage* lReceivedData2;
// ----------------------------------------------
// FUNCTION DEFINITIONS
// ----------------------------------------------
void StartSerialTestTask( unsigned portBASE_TYPE priority ){
//initializations
cr_received = FALSE;
//UARTInit( 2, 9600 );
UARTInit( 1, 115200 );
xQueueHandleGSMSend2 = xQueueCreate(5, sizeof(LogMessage));
//creates task
xTaskCreate( vSerialTestTask, ( signed char * ) "Serial test", UART_STACK_SIZE, NULL, priority, ( xTaskHandle * ) handle );
}
static portTASK_FUNCTION( vSerialTestTask, pvParameters ){
portBASE_TYPE xStatus;
int retVal;
int i;
//cleans buffers
for(i=0; i<SIZE_OF_BUFFER_OUT; i++){
buffer_out[i] = '\0';
second_buffer_out[i] = '\0';
}
while(TRUE){
//clears input buffer
for( i=0; i<SIZE_OF_BUFFER_IN; i++)
buffer_in[i] = '\0';
//THIS WORKS
UART1Send("ATE=0\r");
xStatus = xQueueReceive(xQueueHandleGSMSend2, &lReceivedData2, portMAX_DELAY);
if(xStatus == pdPASS)
{
//THIS BREAKS
UART1Send("ATE=0\r");
}
}
}