STM32 internal temperature sensor experiment summary

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STM32 internal temperature sensor experiment summary [Copy link]

    1.STM32有一个内部的温度传感器，可以用来测量CPU及周围的温度(TA)。
    2.该温度传感器在内部和ADCx_IN16输入通道相连接，此通道把传感器输出的电压转换成数字值。
	3.温度传感器模拟输入推荐采样时间是17.1μs。
	4.STM32的内部温度传感器支持的温度范围为：-40~125度。精度比较差，为±1.5℃左右。
     内部温度传感器更适合于检测温度的变化，而不是测量绝对温度。
     如果需要测量绝度温度，应该使用一个外部温度传感器。

Next, we will start to configure the temperature value inside the chip: [To put it bluntly, the internal temperature sensor is still part of the ADC, so to understand the internal sensor, you must understand the configuration of the ADC]

void  Adc_Temperature_Init(void)
{			
	//第一步：开启PA时钟以及ADC1的通道16的时钟。
	ADC_InitTypeDef ADC_InitStructure;
	RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA | RCC_APB2Periph_ADC1,ENABLE);

	//第二步：复位ADC1，并且设置ADC1的分频因子，让ADC1工作在多少Mhz。
	//		 最高不能超过14MHz.那么我们就6分频，让其工作在12Mhz，因为ADC挂载在
	//		 APB2总线下，也就对应的是PCLK2的时钟，72/6=12;
	RCC_ADCCLKConfig(RCC_PCLK2_Div6);//
	ADC_DeInit(ADC1);//ADC1去初始化

	//第三步：初始化ADC1的相关参数，设置ADC1的工作模式以及规则序列的相关信息
	ADC_InitStructure.ADC_ContinuousConvMode = DISABLE; //工作在单一模式而不是循环模式
	ADC_InitStructure.ADC_DataAlign = ADC_DataAlign_Right;//数据右对齐
	ADC_InitStructure.ADC_ExternalTrigConv = ADC_ExternalTrigConv_None;//转换是没有外部出发启动的。是同过软件转换触发启动
	ADC_InitStructure.ADC_Mode = ADC_Mode_Independent;	//独立模式
	ADC_InitStructure.ADC_NbrOfChannel = 1;							//顺序进行规则转换的ADC1通道数目。这里只有一个通道。
	ADC_InitStructure.ADC_ScanConvMode = DISABLE;				//扫描模式关闭 。扫描模式是用来扫描一组通道的这里我们只用到了一个通道，也就用不到扫描模式，所以失能
	ADC_Init(ADC1,&ADC_InitStructure);//ADC1的初始化。	
	ADC_TempSensorVrefintCmd(ENABLE);//这一步不能忘记了。AD通道方面的配置的差不多了，就要开启内部温度传感器。
	//第四步：使能ADC1并且校准ADC1，【校准之前要进行去校准，等待去校准完成后再进行校准】
	ADC_Cmd(ADC1,ENABLE);
	ADC_GetResetCalibrationStatus(ADC1);//ADC1的去校准
	*while(ADC_GetResetCalibrationStatus(ADC1));	//等待去校准完成。*//当没玩成校准时是1，在循环内死这呢。等待脚注完成，ADC->CR2中的位3就变成0，就跳出循环。哈哈
	
	
	ADC_StartCalibration(ADC1);//ADC1开始校准
	while(ADC_GetCalibrationStatus(ADC1));//等待校准完成	
	}

ps: [Italic part above: while(ADC_GetResetCalibrationStatus(ADC1)); //Wait for calibration to complete. ]
RSTCAL: Reset calibration
This bit is set by software and cleared by hardware. This bit will be cleared after the calibration register is initialized.
0: Calibration register initialized
1: Initialize calibration register
Note: If RSTCAL is set while conversion is in progress, clearing the calibration register requires additional cycles

//Get AD conversion value function

u16 Get_Adc(u8 ch)
{
//Step 5: Configure the working channel parameters, set the specified number of ADC regular channels, one sequence, and a sampling time of 239.5 cycles
ADC_RegularChannelConfig(ADC1,ch,ADC_SampleTime_239Cycles5); //ADC1, ADC channel 16, one sequence, and a sampling time of 239.5 cycles

//Step 6: Enable software conversion function
ADC_SoftwareStartConvCmd(ADC1,ENABLE); //Enable software conversion function of ADC1

while(!ADC_GetFlagStatus(ADC1,ADC_FLAG_EOC) != RESET); //Wait for conversion to complete

return ADC_GetConversionValue(ADC1); //Return the converted AD value.
}


The sample value of the ADC internal temperature sensor is obtained. The value is averaged 10 times for more accuracy.

u16 T_Get_Temp(void)
{
u16 temp_val=0;
u8 t;
for(t=0;t<10;t++)
{
temp_val+=Get_Adc(ADC_Channel_16); //TampSensor
delay_ms(5);
}
return temp_val/10;
}

//Get the conversion average value of channel ch. Take times and then calculate the average.

u16 T_Get_Adc_Average(u8 ch,u8 times)
{
u32 temp_val=0;
u8 t;
for(t=0;t<times;t++)
{
temp_val+=Get_Adc(ch);
delay_ms(5);
}
return temp_val/times;
}

//Get the temperature value. The temperature value is expanded by 100 times, unit: Celsius.

short Get_Temprate(void) //Get the temperature value of the internal temperature sensor
{
u32 adcx;
short result;
double temperate;
adcx=T_Get_Adc_Average(ADC_Channel_16,20); //Channel 16, read 20 times
temperate=(float)adcx*(3.3/4096); //The voltage value obtained.
temperate=(1.43-temperate)/0.0043+25; //Convert to temperature value
result=temperate*=100; //Enlarge 100 times. It is better to display on LCD
return result;
}

Gen_X

Very detailed! Learned!

Internal temperature measurements do have large errors. Good for detecting relative changes or trends.

book1

Great article!

zhangdaoyu

I have learned that I have always wanted to give up the external temperature to reduce costs.

baopodao

It is sufficient for general temperature compensation.

Verifone

It is enough for general environment. The article is good and worth learning from.