[STM32G4] SR04超聲波模組測距
為了提高測量精度採用平均值濾波經過多次測量提高測量精度。我使用STM32NUCLEO-G431RB開發板做的,這裡使用cubeMX選擇該開發板配置
/*WithGCC,smallprintf(optionLDLinker->Libraries->Smallprintf
uint8_t1,0xFFFF);
returnch;
以實現串列埠printf函式的對映,同時在工程配置中啟用MicroLIB即可。標頭檔案當然要引用一下stdio.h為了方便程式碼閱讀,對TRIG觸發引腳的高低電平設定瞭如下巨集定義。
並聲明瞭幾個變數用於儲存臨時資料
floatt1,t2,temp[5],average,distance;
inti=0;
每個週期的測量會產生兩個計數器的值t1,t2,t2-t1時間差就是模組反饋回來的高電平時長,儲存到temp陣列內,測完幾組資料後計算出時間差的平均值,然後計算長度。迴圈臨時變數為i.
5;)
0;
TRIG_LOW;
TRIG_HIGH;
HAL_Delay(1);
TRIG_LOW;
t1=htim2.Instance->CNT;
t2=htim2.Instance->CNT;
0;
if(t2>=t1)
temp[i]=t2-t1;
i++;
HAL_Delay(50);
average=0;
5;i++)
average=average+temp[i];
average=average/5.0;
distance=average*17/1000;
printf("Distance=%.1fcm\n",distance);
*[url=home.php?mod=space&uid=288409]@file[/url]:main.c
*[url=home.php?mod=space&uid=247401]@brief[/url]:Mainprogrambody
*<h2><center>©Copyright(c)2022STMicroelectronics.
*Allrightsreserved.</center></h2>
*the"License";Youmaynotusethisfileexceptincompliancewiththe
floatt1,t2,temp,distance;
inti=0;
UART_HandleTypeDefhlpuart1;
TIM_HandleTypeDefhtim2;
voidSystemClock_Config(void);
staticvoidMX_GPIO_Init(void);
staticvoidMX_LPUART1_UART_Init(void);
staticvoidMX_TIM2_Init(void);
/*WithGCC,smallprintf(optionLDLinker->Libraries->Smallprintf
*[url=home.php?mod=space&uid=247401]@brief[/url]Theapplicationentrypoint.
HAL_Init();
SystemClock_Config();
MX_GPIO_Init();
MX_LPUART1_UART_Init();
MX_TIM2_Init();
Error_Handler();
HAL_TIM_Base_Start(&htim2);
htim2.Instance->CNT=0;
TRIG_LOW;
TRIG_HIGH;
HAL_Delay(1);
TRIG_LOW;
t1=htim2.Instance->CNT;
t2=htim2.Instance->CNT;
htim2.Instance->CNT=0;
if(t2>=t1)
temp=t2-t1;
HAL_Delay(100);
distance=temp*17/1000;
printf("Distance=%.1fcm\n",distance);
HAL_Delay(2000);
RCC_OscInitTypeDefRCC_OscInitStruct={0};
RCC_ClkInitTypeDefRCC_ClkInitStruct={0};
RCC_PeriphCLKInitTypeDefPeriphClkInit={0};
HAL_PWREx_ControlVoltageScaling(PWR_REGULATOR_VOLTAGE_SCALE1);
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_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();
PeriphClkInit.PeriphClockSelection=RCC_PERIPHCLK_LPUART1;
PeriphClkInit.Lpuart1ClockSelection=RCC_LPUART1CLKSOURCE_PCLK1;
if(HAL_RCCEx_PeriphCLKConfig(&PeriphClkInit)!=HAL_OK)
Error_Handler();
hlpuart1.Instance=LPUART1;
hlpuart1.Init.BaudRate=115200;
hlpuart1.Init.WordLength=UART_WORDLENGTH_8B;
hlpuart1.Init.StopBits=UART_STOPBITS_1;
hlpuart1.Init.Parity=UART_PARITY_NONE;
hlpuart1.Init.Mode=UART_MODE_TX_RX;
hlpuart1.Init.HwFlowCtl=UART_HWCONTROL_NONE;
hlpuart1.Init.OneBitSampling=UART_ONE_BIT_SAMPLE_DISABLE;
hlpuart1.Init.ClockPrescaler=UART_PRESCALER_DIV1;
hlpuart1.AdvancedInit.AdvFeatureInit=UART_ADVFEATURE_NO_INIT;
if(HAL_UART_Init(&hlpuart1)!=HAL_OK)
Error_Handler();
if(HAL_UARTEx_SetTxFifoThreshold(&hlpuart1,UART_TXFIFO_THRESHOLD_1_8)!=HAL_OK)
Error_Handler();
if(HAL_UARTEx_SetRxFifoThreshold(&hlpuart1,UART_RXFIFO_THRESHOLD_1_8)!=HAL_OK)
Error_Handler();
if(HAL_UARTEx_DisableFifoMode(&hlpuart1)!=HAL_OK)
Error_Handler();
TIM_ClockConfigTypeDefsClockSourceConfig={0};
TIM_MasterConfigTypeDefsMasterConfig={0};
htim2.Instance=TIM2;
htim2.Init.Prescaler=15;
htim2.Init.CounterMode=TIM_COUNTERMODE_UP;
htim2.Init.Period=49999;
htim2.Init.ClockDivision=TIM_CLOCKDIVISION_DIV1;
htim2.Init.AutoReloadPreload=TIM_AUTORELOAD_PRELOAD_DISABLE;
if(HAL_TIM_Base_Init(&htim2)!=HAL_OK)
Error_Handler();
sClockSourceConfig.ClockSource=TIM_CLOCKSOURCE_INTERNAL;
if(HAL_TIM_ConfigClockSource(&htim2,&sClockSourceConfig)!=HAL_OK)
Error_Handler();
sMasterConfig.MasterOutputTrigger=TIM_TRGO_RESET;
sMasterConfig.MasterSlaveMode=TIM_MASTERSLAVEMODE_DISABLE;
if(HAL_TIMEx_MasterConfigSynchronization(&htim2,&sMasterConfig)!=HAL_OK)
Error_Handler();
GPIO_InitTypeDefGPIO_InitStruct={0};
__HAL_RCC_GPIOC_CLK_ENABLE();
__HAL_RCC_GPIOF_CLK_ENABLE();
__HAL_RCC_GPIOA_CLK_ENABLE();
__HAL_RCC_GPIOB_CLK_ENABLE();
HAL_GPIO_WritePin(TRIG_GPIO_Port,TRIG_Pin,GPIO_PIN_RESET);
HAL_GPIO_WritePin(LD2_GPIO_Port,LD2_Pin,GPIO_PIN_RESET);
GPIO_InitStruct.Pin=B1_Pin;
GPIO_InitStruct.Mode=GPIO_MODE_IT_RISING;
GPIO_InitStruct.Pull=GPIO_NOPULL;
HAL_GPIO_Init(B1_GPIO_Port,&GPIO_InitStruct);
GPIO_InitStruct.Pin=TRIG_Pin;
GPIO_InitStruct.Mode=GPIO_MODE_OUTPUT_PP;
GPIO_InitStruct.Pull=GPIO_NOPULL;
GPIO_InitStruct.Speed=GPIO_SPEED_FREQ_LOW;
HAL_GPIO_Init(TRIG_GPIO_Port,&GPIO_InitStruct);
GPIO_InitStruct.Pin=ECHO_Pin;
GPIO_InitStruct.Mode=GPIO_MODE_INPUT;
GPIO_InitStruct.Pull=GPIO_NOPULL;
HAL_GPIO_Init(ECHO_GPIO_Port,&GPIO_InitStruct);
GPIO_InitStruct.Pin=LD2_Pin;
GPIO_InitStruct.Mode=GPIO_MODE_OUTPUT_PP;
GPIO_InitStruct.Pull=GPIO_NOPULL;
GPIO_InitStruct.Speed=GPIO_SPEED_FREQ_LOW;
HAL_GPIO_Init(LD2_GPIO_Port,&GPIO_InitStruct);
HAL_UART_Transmit(&hlpuart1,(uint8_t*)&ch,1,0xFFFF);
returnch;
__disable_irq();
while(1)
{
}
/*USERCODEENDError_Handler_Debug*/
}
#ifdefUSE_FULL_ASSERT
/**
*@briefReportsthenameofthesourcefileandthesourcelinenumber
*wheretheassert_paramerrorhasoccurred.
*@paramfile:pointertothesourcefilename
*@paramline:assert_paramerrorlinesourcenumber
*@retvalNone
*/
voidassert_failed(uint8_t*file,uint32_tline)
{
/*USERCODEBEGIN6*/
/*Usercanaddhisownimplementationtoreportthefilenameandlinenumber,
ex:printf("Wrongparametersvalue:file%sonline%d\r\n",file,line)*/
/*USERCODEEND6*/
}
#endif/*USE_FULL_ASSERT*/
/************************(C)COPYRIGHTSTMicroelectronics*****ENDOFFILE****/
---------------------
作者:gaoyang9992006
連結:https://bbs.21ic.com/icview-3197516-1-1.html
來源:21ic.com
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