Use case: USART TX RX in interrupt mode

Sequence diagram

USART transmit and receive in interrupt mode

@startuml
participant "User Application" as p1
participant "HAL USART driver" as p2
participant "USARTX_IRQHandler" as p3
== USART HAL TransmitReceive IT ==

p1->p2: <color: green> HAL_USART_TransmitReceive_IT(&husart, aTxBuffer, aRxBuffer, DATA_TO_SEND_SIZE)
note over p2 #00FF00
Transmitting and receiving data ongoing
end note
p2-->p1: HAL_OK
p3<-: USARTX data interrupt
p3->p2: HAL_USART_IRQHandler
note over p2 #FFFF99
All data (Size == husart->TxXferCount and Size == husart->RxXferCount) have been transmitted and received
end note
note over p2 #00FF00
End of transmitting and receiving data
end note
p2->p1: HAL_USART_TxRxCpltCallback(&husart->TxXferCount, husart->RxXferCount)

@enduml

Code snippet

HAL1

HAL2

#define DATA_TO_SEND_SIZE           256

#define DATA_TO_RECEIVE_SIZE       DATA_TO_SEND_SIZE

uint8_t aTxBuffer[] = " **** USART_SlaveMode **** ";
uint8_t aRxBuffer[DATA_TO_RECEIVE_SIZE];

USART_HandleTypeDef husart;

/* Ensure that all required peripherals
(USART, GPIO, NVIC,etc.) are configured properly
/*
...
*/

/* USART register TransmitReceive complete user callback */
HAL_USART_RegisterCallback(&husart, HAL_USART_TX_RX_CB_ID, USART_TxRxCpltCallback);

/* Start a USART TransmitReceive process in interruption mode */
HAL_USART_TransmitReceive_IT(&husart, aTxBuffer, aRxBuffer, DATA_TO_SEND_SIZE)
#define DATA_TO_SEND_SIZE           256

#define DATA_TO_RECEIVE_SIZE       DATA_TO_SEND_SIZE

uint8_t aTxBuffer[] = " **** USART_SlaveMode **** ";
uint8_t aRxBuffer[DATA_TO_RECEIVE_SIZE];

hal_usart_handle_t husart;

/* Ensure that all required peripherals
(USART, GPIO, NVIC,etc.) are configured properly
/*
...
*/

/* USART register TransmitReceive complete user callback */
HAL_USART_RegisterTxRxCpltCallback(&husart, USART_TxRxCpltCallback);

/* Start a USART TransmitReceive process in interruption mode */
HAL_USART_TransmitReceive_IT(&husart, aTxBuffer, aRxBuffer, DATA_TO_RECEIVE_SIZE)

Key changes

  1. HAL2 provides a dedicated registration API for TX/RX completion callbacks: HAL_USART_RegisterTxRxCpltCallback().

  2. HAL2 uses byte-oriented transfer count fields (for example tx_xfer_count and rx_xfer_count).