如何使用LM35测量摄氏度、华氏度和开尔文温度
在本教程中,我们将学习如何使用LM35温度传感器来测量温度,并在串口监视器上以摄氏度、华氏度和开尔文显示。LM35是一个简单而有效的传感器,它输出与温度成比例的电压,从而便于读取和转换。该项目非常适合希望将温度传感器集成到其Arduino项目中的初学者。

硬件解析
LM35温度传感器是一种高精度设备,提供与摄氏温度对应的模拟电压输出。该传感器的工作范围为-55°C到150°C,精度为±0.5°C。其60微安的低功耗使其适合电池供电的设备。 LM35的输出阻抗低,能够有效驱动负载而不会出现显著的电压下降,这对于保持准确的读数至关重要。该传感器通常采用TO-92封装,便于集成到各种项目中。
数据表详情
| 制造商 | 德州仪器 |
|---|---|
| 零件编号 | LM35 |
| 逻辑/IO电压 | 4-30 伏 |
| 输出电流(典型) | 60 微安培 |
| 温度范围 | -55 至 150 °C |
| 输出电压 | 10 mV/°C |
| 精度(典型) | ±0.5 °C (最高可达 25 °C) |
| 包裹 | TO-92 |
- 确保电源供应在4V到30V之间。
- 注意电源连接的极性反向。
- 使用稳定的接地连接以避免读数中的噪声。
- 将传感器远离直接热源,以防止出现错误读数。
- 如果您在输出电压中经历波动,考虑使用低通滤波器。
接线说明

将LM35传感器接线,左脚(VCC)连接到Arduino的5V电源。右脚(GND)应连接到Arduino的地(GND)。中间脚(输出)是读取温度数据的地方;将此引脚连接到模拟输入引脚。A0在Arduino上。这种设置将允许Arduino读取来自LM35的电压输出,该电压对应于温度。
如果您需要调整不同配置的接线,请确保在代码中更新模拟引脚引用以匹配您的新设置。(在视频中于03:15)
代码示例和演练
以下代码片段演示了如何从LM35读取温度并以不同单位显示它。 首先,我们定义输入引脚和LM35转换因子:
const int inPin = A0; // can change
const float LM35_FACTOR = 0.01; // do not change在这个片段中,inPin表示连接到LM35输出的模拟引脚,和LM35_FACTOR定义将电压转换为摄氏温度所需的转换。
接下来,我们建立串行通信:
void setup() {
Serial.begin(9600);
Serial.println("Robojax LM35 for Arduino");
delay(500);
}这里,Serial.begin(9600)以9600波特率初始化串口通信,允许我们与串口监视器发送和接收数据。
循环函数持续读取温度并打印出来:
void loop() {
printTemperature('C');
printTemperature('F');
printTemperature('K');
delay(1000);
}在这个循环中,我们调用了printTemperature每个单位(摄氏度,华氏度,开尔文)的函数,用于在串口监视器上显示相应的温度。
演示 / 什么可以期待
当LM35连接正确时,您应该在串行监视器上看到以摄氏度、华氏度和开尔文显示的温度读数。当您给传感器加热时,读数将相应增加。如果您注意到任何随机或不稳定的值,请检查您的接线,以确保没有松动的连接或错误的引脚分配。(视频中在05:00)
视频时间戳
- 00:00- 介绍
- 01:00- LM35 概述
- 02:30- 接线说明
- 03:15- 代码解释
- 05:00- 示范
/*
* This Arduino sketch is to use LM35 to measure temperature
* This code has two ways to get temperature
* 1-To print the temperature either in C, F or K on the serial monitor
* 2-To return the value in C, F and K
*
* Watch Video instruction for this code:https://youtu.be/S5IBc_epa1A
*
* Full explanation of this code and wiring diagram is available at
* my Arduino Course at Udemy.com here: http://robojax.com/L/?id=62
* Written by Ahmad Shamshiri on May 08, 2020 at 02:45 in Ajax, Ontario, Canada
* in Ajax, Ontario, Canada. www.robojax.com
*
* Get this code and other Arduino codes from Robojax.com
Learn Arduino step by step in a structured course with all material, wiring diagrams and libraries
all in one place. Purchase My course on Udemy.com http://robojax.com/L/?id=62
If you found this tutorial helpful, please support me so I can continue creating
content like this.
or make a donation using PayPal http://robojax.com/L/?id=64
* * This code is "AS IS" without warranty or liability. Free to be used as long as you keep this note intact.*
* This code has been downloaded from Robojax.com
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <https://www.gnu.org/licenses/>.
*/
const int inPin =A0;//can change
const int iteration = 1000; //can change (see video)
const float LM35_FACTOR =0.01;// do not change
// the setup routine runs once when you press reset:
void setup() {
// initialize serial communication at 9600 bits per second:
Serial.begin(9600);
Serial.println("Robojax LM35 for Arduino");
delay(500);
}
// the loop routine runs over and over again forever:
void loop() {
//robojax.com LM35 Code for Arduino
printTemperature('C');
Serial.println();
printTemperature('F');
Serial.println();
printTemperature('K');
Serial.println();
Serial.println();
// Serial.print(" Temperature: ");
// printDegree();
// Serial.print(getTemperature('C'));
if(getTemperature('C') >87)
{
// do something here (watch video)
}
// Serial.println();
delay(1000);
}
/*
* getTemperature()
* @brief gets the average temperature
* @param average temperature
* @param "type" is character
* C = Celsius
* K = Kelvin
* F = Fahrenheit
* @return returns one of the values above
* Written by Ahmad Shamshiri for robojax.com
* on May 08, 2020 at 02:36 in Ajax, Ontario, Canada
*/
float getTemperature(char type)
{
float value;
float averageTemperature =0;
int sensorValue = analogRead(inPin);
float voltage = sensorValue * (5.0 / 1023.0);
float temperature = voltage / LM35_FACTOR;
for(int i=0; i< iteration; i++)
{
averageTemperature += temperature;
}
averageTemperature /=iteration;
if(type =='F')
{
value = averageTemperature *9/5 + 32;//convert to Fahrenheit
}else if(type =='K')
{
value = averageTemperature + 273.15;//convert to Kelvin
}else{
value = averageTemperature;// return Celsius
}
return value ;
}//getTemperature()
/*
* printTemperature()
* @brief prints temperature on serial monitor
* @param character type
* @param "type" is character
* C = Celsius
* K = Kelvin
* F = Fahrenheit
* @return none
* Written by Ahmad Shamshiri for robojax.com
* on May 08, 2020 at 02:45 in Ajax, Ontario, Canada
*/
void printTemperature(char type)
{
float value;
float temp = getTemperature(type);
Serial.print(temp);
printDegree();
if(type =='F')
{
Serial.print("F");
}else if(type =='K')
{
Serial.print("K");
}else{
Serial.print("C");
}
}//printTemperature()
/*
* @brief prints degree symbol on serial monitor
* @param none
* @return returns nothing
* Written by Ahmad Shamshiri on July 13, 2019
* for Robojax Tutorial Robojax.com
*/
void printDegree()
{
Serial.print("\\xC2");
Serial.print("\\xB0");
}
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资源与参考
-
产品规格书LM35 Datasheetti.com
文件📁
没有可用的文件。