HAL_CAN_IsTxMessagePending() function
Check if a transmission request is pending on the selected Tx Mailboxes.
Arguments
hcan
pointer to an CAN_HandleTypeDef structure that contains the configuration information for the specified CAN.
TxMailboxes
List of Tx Mailboxes to check. This parameter can be any combination of @arg CAN_Tx_Mailboxes.
Return value
Status - 0 : No pending transmission request on any selected Tx Mailboxes. - 1 : Pending transmission request on at least one of the selected Tx Mailbox.