Posted on May 17, 2011 at 13:11Hello every body,
I have a trouble in getting CAN transmission interrupt to work.
How do i activate the interrupt?
I use this while initialising the NVIC:
NVIC_InitStructure.NVIC_IRQChannel = USB_HP_CAN_TX_IRQChannel;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 192;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);
I am using FREERTOS so i need the priority to be higher than 191 in order to make some features work.
And each time i want to send data i put it in a queu and then activate the TX interrupt as follow
void CAN_Write(char* c)
{
char* d=c;
xSemaphoreTake(xCANTXSemaphore,( portTickType ) portMAX_DELAY);
while(*d!=0)
{
xQueueSend(xCANQueuTX, d++,( portTickType ) portMAX_DELAY);
}
CAN_ITConfig(CAN_IT_TME, ENABLE);//on active l'interruption d'ecriture
xSemaphoreGive(xCANTXSemaphore);
}
Then in the IRQ i do this:
void ISR_CANTX()
{
CanTxMsg TxMessage;
portBASE_TYPE xHigherPriorityTaskWoken=pdFALSE ;
TxMessage.StdId=0x11;
TxMessage.RTR=CAN_RTR_DATA;
TxMessage.IDE=CAN_ID_STD;
TxMessage.DLC=2;
//Si il y a encore quoi envoyer on envoi
if(xQueueReceiveFromISR( xRS232QueuTX, &( TxMessage.Data[0] ),&xHigherPriorityTaskWoken))
{
CAN_Transmit(&TxMessage);
}
else//sinon on desactive cette interruption
{
CAN_ITConfig(CAN_IT_TME,DISABLE);
}
CAN_ClearITPendingBit(CAN_IT_TME);
portEND_SWITCHING_ISR( xHigherPriorityTaskWoken );
}
I chack the queu, if there is something to send i send it else i disactivate the interrupt.
I have initialised the interrupts vector to make this routine the one called when an interrupt occurs on USB_HP_CAN_TX_IRQChannel.
Did i miss something, and am i right to use this IRQChannel and this interrupt: CAN_ITConfig(CAN_IT_TME, ENABLE); ?
Thanks
[ This message was edited by: aloui.seifeddine on 12-05-2009 22:59 ]
