I can send data only with the flexcan_drv_send function, in which case should I use the function ConfigTxMb? This two func gets the same parameters.
In FLEXCAN_Set_TxMsgBuff, "Then this function will copy the user's buffer into the message buffer data area and configure the message buffer as required for transmission."
Why we need to "transmit message buffer configuration" ?
Using FLEXCAN_DRV_ConfigTxMb (configure TX message buffer with index TX_MSG_ID and TX_MAILBOX) before FLEXCAN_DRV_Send (execute send non-blocking), you ensure that the Mb is correctly configured to be used it.
The usage of these functions together depends on your application, but one suggested case is to send data via CAN to the specified mailbox with the specified message-id.
I hope this will help you