jordied wrote on Friday, March 27, 2015:
I have a task which is monitoring the status of two push buttons. Called SwitchTask:
while(1) {
//
// Poll the debounced state of the buttons.
//
ui8CurButtonState = ButtonsPoll(0, 0);
//
// Check if previous debounced state is equal to the current state.
//
if(ui8CurButtonState != ui8PrevButtonState)
{
ui8PrevButtonState = ui8CurButtonState;
//
// Check to make sure the change in state is due to button press
// and not due to button release.
//
if((ui8CurButtonState & ALL_BUTTONS) != 0)
{
if((ui8CurButtonState & ALL_BUTTONS) == LEFT_BUTTON)
{
ui8Message = LEFT_BUTTON;
ui8MessageToScreen = LEFT_BUTTON;
//
// Guard UART from concurrent access.
//
xSemaphoreTake(g_pUARTSemaphore, portMAX_DELAY);
UARTprintf("Left Button is pressed.\n");
xSemaphoreGive(g_pUARTSemaphore);
}
else if((ui8CurButtonState & ALL_BUTTONS) == RIGHT_BUTTON)
{
ui8Message = RIGHT_BUTTON;
ui8MessageToScreen = RIGHT_BUTTON;
//
// Guard UART from concurrent access.
//
xSemaphoreTake(g_pUARTSemaphore, portMAX_DELAY);
UARTprintf("Right Button is pressed.\n");
xSemaphoreGive(g_pUARTSemaphore);
}
//
// Pass the value of the button pressed to LEDTask.
//
if(xQueueSend(g_pScreenButtonQueue, &ui8MessageToScreen, portMAX_DELAY) !=
pdPASS)
{
//
// Error. The queue should never be full. If so print the
// error message on UART and wait for ever.
//
UARTprintf("\nScreen Queue full. This should never happen.\n");
while(1)
{
}
}
if(xQueueSendToFront(g_pScreenButtonQueue, &ui8Message, portMAX_DELAY) !=
pdPASS)
{
//
// Error. The queue should never be full. If so print the
// error message on UART and wait for ever.
//
UARTprintf("LED Queue full. This should never happen.\n");
while(1)
{
}
}
}
}
//
// Wait for the required amount of time to check back.
//
vTaskDelayUntil(&ui16LastTime, ui32SwitchDelay / portTICK_RATE_MS);
}
I haev tried xQueueSend, xQueueSendToFront and xQueueSendToBack. The Queues are initialized like this:
g_pLEDQueue = xQueueCreate(5, sizeof(uint8_t));
g_pScreenButtonQueue = xQueueCreate(5, sizeof(uint8_t));
However only the Screen Task actually receives . They are called like this:
if(xQueueReceive(g_pScreenButtonQueue, &i8MessageFromButton,10) == pdPASS) {
// Does stuff
}
if(xQueueReceive(g_pLEDQueue , &i8Message,10) == pdPASS) {
// Does stuff
}
I have tired butting 0 and 10.
If I swap the order of the If statements for the send then it works. Any ideas?