【发布时间】：2020-08-06 03:20:58
【问题描述】：
我开始在 STM32F103xx MCU 中基本使用 HAL 驱动程序来实现 CAN 外设的环回模式。根据单片机的用户手册，当传输完成且数据在CAN总线上可用时，硬件置位CAN_TSR寄存器的TME、RQCP和TXOK位，表示对应的邮箱已为空，传输成功。
当我调试以下程序时，CAN_TSR 寄存器中没有发生上述更改。我只能看到 TME 位被设置，这意味着提供了一个邮箱用于传输但从未传输。
我的这段代码导致程序中出现不定式循环：
while(HAL_CAN_IsTxMessagePending(&hcan, TxMailbox));
你能解释一下我的问题是什么，我应该怎么做。感谢您的想法。
这是完整的代码：
#include "main.h"
CAN_HandleTypeDef hcan;
void SystemClock_Config(void);
static void MX_GPIO_Init(void);
static void MX_CAN_Init(void);
/* USER CODE BEGIN PFP */
void Can_TX(void);
/* USER CODE END PFP */
int main(void)
{
/* Reset of all peripherals, Initializes the Flash interface and the Systick. */
HAL_Init();
/* Configure the system clock */
SystemClock_Config();
/* Initialize all configured peripherals */
MX_GPIO_Init();
MX_CAN_Init();
/* USER CODE BEGIN 2 */
LCD1602_Begin4BIT(RS_GPIO_Port, RS_Pin, E_Pin, D4_GPIO_Port, D4_Pin, D5_Pin, D6_Pin, D7_Pin);
LCD1602_print("Sending...");
Can_TX();
/* USER CODE END 2 */
/* Infinite loop */
while (1)
{
for (int i = 0; i <= 1000; i++);
}
}
void SystemClock_Config(void)
{
RCC_OscInitTypeDef RCC_OscInitStruct = {0};
RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};
RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSI;
RCC_OscInitStruct.HSIState = RCC_HSI_ON;
RCC_OscInitStruct.HSICalibrationValue = RCC_HSICALIBRATION_DEFAULT;
RCC_OscInitStruct.PLL.PLLState = RCC_PLL_NONE;
if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
{
Error_Handler();
}
RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK|RCC_CLOCKTYPE_SYSCLK|RCC_CLOCKTYPE_PCLK1|RCC_CLOCKTYPE_PCLK2;
RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_HSI;
RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV1;
RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;
if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_0) != HAL_OK)
{
Error_Handler();
}
}
static void MX_CAN_Init(void)
{
hcan.Instance = CAN1;
hcan.Init.Prescaler = 1;
hcan.Init.Mode = CAN_MODE_LOOPBACK;
hcan.Init.SyncJumpWidth = CAN_SJW_1TQ;
hcan.Init.TimeSeg1 = CAN_BS1_13TQ;
hcan.Init.TimeSeg2 = CAN_BS2_2TQ;
hcan.Init.TimeTriggeredMode = DISABLE;
hcan.Init.AutoBusOff = DISABLE;
hcan.Init.AutoWakeUp = DISABLE;
hcan.Init.AutoRetransmission = ENABLE;
hcan.Init.ReceiveFifoLocked = DISABLE;
hcan.Init.TransmitFifoPriority = DISABLE;
if (HAL_CAN_Init(&hcan) != HAL_OK)
{
Error_Handler();
}
}
static void MX_GPIO_Init(void)
{
GPIO_InitTypeDef GPIO_InitStruct = {0};
__HAL_RCC_GPIOA_CLK_ENABLE();
HAL_GPIO_WritePin(GPIOA, RS_Pin|E_Pin|D4_Pin|D5_Pin|D6_Pin|D7_Pin, GPIO_PIN_RESET);
GPIO_InitStruct.Pin = RS_Pin|E_Pin|D4_Pin|D5_Pin|D6_Pin|D7_Pin;
GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
GPIO_InitStruct.Pull = GPIO_NOPULL;
GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);
}
void Can_TX(void)
{
CAN_TxHeaderTypeDef TxHeader;
uint8_t our_message[5] = {'H','E','L','L','O'};
uint32_t TxMailbox;
TxHeader.DLC = 1;
TxHeader.StdId = 0x65D;
TxHeader.IDE = CAN_ID_STD;
TxHeader.RTR = CAN_RTR_DATA;
HAL_CAN_AddTxMessage(&hcan, &TxHeader, our_message, &TxMailbox);
if(HAL_CAN_AddTxMessage(&hcan, &TxHeader, our_message, &TxMailbox) != HAL_OK)
{
Error_Handler();
}
while(HAL_CAN_IsTxMessagePending(&hcan, TxMailbox));
LCD1602_print("Message is sent");
}
void Error_Handler(void) { }
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标签： c embedded stm32 can-bus hal