if (hcan->State == HAL_CAN_STATE_READY) { /* Change CAN peripheral state */ hcan->State = HAL_CAN_STATE_LISTENING; /* Request leave initialisation */ CLEAR_BIT(hcan->Instance->MCR, CAN_MCR_INRQ); /* Get tick */ tickstart = HAL_GetTick(); /* Wait the acknowledge */ while ((hcan->Instance->MSR & CAN_MSR_INAK) != 0U) { /* Check for the Timeout */ 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; } } /* Reset the CAN ErrorCode */ hcan->ErrorCode = HAL_CAN_ERROR_NONE; /* Return function status */ return HAL_OK; } else { /* Update error code */ hcan->ErrorCode |= HAL_CAN_ERROR_NOT_READY; return HAL_ERROR; 什么作用

这段代码是用于等待CAN总线进入"Listening"状态的函数，函数名可能是`HAL_CAN_WaitForListning()`或者类似的。首先，它检查CAN总线是否处于"Ready"状态，如果不是，则返回错误代码。如果总线已经准备好，则将其状态更改为"Listening"，并且请求CAN控制器离开初始化模式。然后等待CAN控制器进入"Active"模式，以便可以开始发送和接收CAN帧。如果在规定时间内CAN控制器未能成功进入"Active"模式，则返回一个超时错误码和错误状态。如果成功进入"Active"模式，则重置错误代码并返回成功状态。

相关问题

stm32f103cb基于HAL库的CAN代码，接收为中断接收

STM32F103CB基于HAL库的CAN驱动程序通常会采用中断方式来实现接收。以下是基本的步骤和示例代码：

1. **初始化CAN模块**:

void CAN_Init(void) {
    GPIO_InitTypeDef GPIO_InitStructure;
    
    // CAN RX/TX pins configuration
    GPIO_InitStructure.Pin = GPIO_PIN_9 | GPIO_PIN_10;
    GPIO_InitStructure.Speed = GPIO_SPEED_FREQ_VERY_HIGH;
    GPIO_InitStructure.Mode = GPIO_MODE_AF_PP;
    GPIO_InitStructure.Pull = GPIO_NOPULL;
    GPIO_InitStructure.Alternate = GPIO_AF11_CAN1;
    HAL_GPIO_Init(GPIOA, &GPIO_InitStructure);
    
    // Initialize the CAN peripheral
    hcan.Instance = CAN1;
    hcan.Init.Prescaler = 1; // 分频系数
    hcan.Init.Mode = CAN_MODE_NORMAL;
    hcan.Init.SJW = CAN_SJW_1TQ;
    hcan.Init.Timing.BaseJitter = 0;
    hcan.Init.Timing.BS1Jitter = 0;
    hcan.Init.Timing.BS2Jitter = 0;
    hcan.Init.Timing.TransmitFilter = CAN_FILTER_NONE;
    hcan.Init.ReceptionFifoMode = CAN_RFIFO_MODE_NORMAL;
    HAL_CAN_Init(&hcan);
}

2. **设置中断处理**:

void CAN_Configuration(void) {
    CAN_ITConfigTypeDef itConfig;

    itConfig.RxEventCallback = CAN Rx Interrupt Handler; // 定义中断回调函数
    itConfig.ExtendedIDFilter = ENABLE;
    itConfig.InterruptMode = ENABLE; // 接收中断
    HAL_CAN_MasterConfigIT(&hcan, &itConfig);
}

3. **启用中断并注册中断服务函数**:

void EnableCanInterrupts(void) {
    HAL_NVIC_SetPriority(CAN1_IRQn, 4, 1); // 高优先级
    HAL_NVIC_EnableIRQ(CAN1_IRQn);
}

void CAN_IRQHandler(void) {
    HAL_CAN_IRQHandler(&hcan); // 处理中断

    if (HAL_CAN_GetRxBufferFlag(&hcan, CAN_FLAG_RXNE)) { // 判断是否有新的接收数据
        uint8_t RxBuffer[8]; // 数据缓冲区
        HAL_CAN_Receive(&hcan, RxBuffer, sizeof(RxBuffer)); // 读取接收缓冲区
        // 处理接收到的数据...
        HAL_CAN_ClearRxBufferFlag(&hcan, CAN_FLAG_RXNE); // 清除接收标志
    }
}

stm32f103c8t6 串口接收HAL

### STM32F103C8T6 HAL UART Receive Example Code

For the STM32F103C8T6 microcontroller using the Hardware Abstraction Layer (HAL) library to implement UART reception, a typical setup involves initializing the UART peripheral and configuring it for receiving data. Below is an example of how this can be achieved:

#### Initialization Function
The initialization function sets up the UART parameters such as baud rate, word length, stop bits, parity mode, hardware flow control, etc.

#include "stm32f1xx_hal.h"

UART_HandleTypeDef huart1;

void MX_USART1_UART_Init(void)
{
    huart1.Instance = USART1;
    huart1.Init.BaudRate = 9600;
    huart1.Init.WordLength = UART_WORDLENGTH_8B;
    huart1.Init.StopBits = UART_STOPBITS_1;
    huart1.Init.Parity = UART_PARITY_NONE;
    huart1.Init.Mode = UART_MODE_TX_RX;
    huart1.Init.HwFlowCtl = UART_HWCONTROL_NONE;
    huart1.Init.OverSampling = UART_OVERSAMPLING_16;
    if (HAL_UART_Init(&huart1) != HAL_OK)
    {
        Error_Handler();
    }
}

This configuration initializes `USART1` with common settings suitable for basic communication tasks[^1].

#### Receiving Data Using Polling Method
To receive data via polling method, one would use the following approach which waits until there's incoming data on the line before proceeding further.

uint8_t receivedData[20]; // Buffer to store received bytes

if(HAL_UART_Receive(&huart1, receivedData, sizeof(receivedData), HAL_MAX_DELAY)== HAL_OK){
    // Process Received Data Here...
} else {
    // Handle error here...
}

In addition to these snippets, comprehensive documentation about the HAL library including detailed descriptions of functions used above like `HAL_UART_Init()` or `HAL_UART_Receive()`, along with their respective parameter lists and return values should also be consulted from official sources provided by STMicroelectronics.

--related questions--

1. How does interrupt-based UART reception differ from polling-based methods?
2. What are some best practices when working with UART interfaces on STM32 devices?
3. Can you provide examples of handling errors during UART transmission/reception operations?
4. Is DMA supported for UART transfers in STM32F1 series? If yes, what advantages does it offer over standard modes?
5. Are there any specific considerations while choosing between different types of UART configurations available within the HAL API?