Posted on May 01, 2018 at 04:39Hello
I am trying to use the stm32f7xx_hal_can driver on Nucleo 144 F767ZI , and the code is stuck at the init state.
While using the debugger and reading the Reference manual i found the fallowing:
- the initial state of the CAN contoller is SLEEP state
- To exit the sleep state it is needed to clear the
SLEEP bit in the MCR register
- Then the CAN controller acknowledge to the software that he move from SLEEP state by clear SLAK bit in MSR
register
I did not connect the can transceiver yet.
here is the the code 'stm32f7xx_hal_can.c' I mark the line were the program stuck
HAL_StatusTypeDef HAL_CAN_Init(CAN_HandleTypeDef *hcan)
{
uint32_t tickstart = 0U;
/* Check CAN handle */
if (hcan == NULL)
{
return HAL_ERROR;
}
/* Check the parameters */
assert_param(IS_CAN_ALL_INSTANCE(hcan->Instance));
assert_param(IS_FUNCTIONAL_STATE(hcan->Init.TimeTriggeredMode));
assert_param(IS_FUNCTIONAL_STATE(hcan->Init.AutoBusOff));
assert_param(IS_FUNCTIONAL_STATE(hcan->Init.AutoWakeUp));
assert_param(IS_FUNCTIONAL_STATE(hcan->Init.AutoRetransmission));
assert_param(IS_FUNCTIONAL_STATE(hcan->Init.ReceiveFifoLocked));
assert_param(IS_FUNCTIONAL_STATE(hcan->Init.TransmitFifoPriority));
assert_param(IS_CAN_MODE(hcan->Init.Mode));
assert_param(IS_CAN_SJW(hcan->Init.SyncJumpWidth));
assert_param(IS_CAN_BS1(hcan->Init.TimeSeg1));
assert_param(IS_CAN_BS2(hcan->Init.TimeSeg2));
assert_param(IS_CAN_PRESCALER(hcan->Init.Prescaler));
if (hcan->State == HAL_CAN_STATE_RESET)
{
/* Init the low level hardware: CLOCK, NVIC */
HAL_CAN_MspInit(hcan);
}
/* Exit from sleep mode */
CLEAR_BIT(hcan->Instance->MCR, CAN_MCR_SLEEP); <--- clear the SLEEP bit
/* Get tick */
tickstart = HAL_GetTick();
/* Check Sleep mode leave acknowledge */
while ((hcan->Instance->MSR & CAN_MSR_SLAK) != RESET) <---------- stuck here while waiting for ack {
if ((HAL_GetTick() - tickstart) > CAN_TIMEOUT_VALUE)
{
/* Update error code */
hcan->ErrorCode |= HAL_CAN_ERROR_TIMEOUT;
/* Change CAN state */
hcan->State = HAL_CAN_STATE_ERROR;
return HAL_ERROR;
}
}
....
Does anyone have an idea why ?
