Use case: USART RX in interrupt mode

Sequence diagram

USART receive in interrupt mode

@startuml participant "User Application" as p1 participant "HAL USART driver" as p2 participant "USARTX_IRQHandler" as p3 == USART HAL Receive IT == p1->p2: <color: green> HAL_USART_Receive_IT(&husart, aRxBuffer, DATA_TO_RECEIVE_SIZE) note over p2 #00FF00 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->RxXferCount) have been received end note note over p2 #00FF00 End of receiving data end note p2->p1: HAL_USART_RxCpltCallback(&husart->RxXferCount) @enduml

Code snippet

HAL1

HAL2 

#define DATA_TO_RECEIVE_SIZE       256

uint8_t aRxBuffer[DATA_TO_RECEIVE_SIZE];

USART_HandleTypeDef husart;

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

/* USART register Receive complete user callback */
HAL_USART_RegisterCallback(&husart, HAL_USART_RX_CB_ID,
                               USART_RxCpltCallback);

/* Start a USART Process in interruption mode */
HAL_USART_Receive_IT(&husart, aRxBuffer,
                           DATA_TO_RECEIVE_SIZE)

#define DATA_TO_RECEIVE_SIZE       256

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 Receive complete user callback */
HAL_USART_RegisterRxCpltCallback(&husart, USART_RxCpltCallback);


/* Start a USART Process in interruption mode */
HAL_USART_Receive_IT(&husart, aRxBuffer,
                        DATA_TO_RECEIVE_SIZE)

Key changes

  1. HAL2 provides a dedicated registration API for RX completion callbacks: HAL_USART_RegisterRxCpltCallback().

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