Lesson 24--Microduino Digital Tube Thermometer

Language	English

Objective This tutorial will teach you how to use the DS18B20 temperature sensor get the temperature value and display on digital tube. Equipment Microduino-Core Microduino-FT232R Other hardware equipment Breadboard Jumper one box Breadboard one piece DS18B20 sensor one Digital tube one USB cable one Speaker DS18B20 is a commonly used temperature sensor, it has the the advantages of small volume, low hardware overhead, strong anti-jamming capability and high precision. Correct connection: Facing the flat side, left is the negative and right is positive. Once the connection is wrong, it will heat up immediately, may burn! At the same time, this is also the cause of the sensor always displays 85℃. Schematic Pin Table Microduino Pin Digital Tube D2 10(A) D3 9(B) D4 1(C) D5 4(D) D6 3(E) D7 6(F) D8 5(G) 9 2(DP) D10 8(LED1) D11 7(LED2) Program byte digit0 = 10; //Ten digits bit byte digit1 = 11; //Single digits bit byte dotPin = 2; //Decimal point of digital tube byte sevenSegmentPins[] = { 2,3,4,5,6,7,8}; //A,B,C,D,E,F,G's Microduino pin byte sevenSegment[10][7] = { //a b c d e f g { 0,0,0,0,0,0,1 } , // = 0 { 1,0,0,1,1,1,1 } , // = 1 { 0,0,1,0,0,1,0 } , // = 2 { 0,0,0,0,1,1,0 } , // = 3 { 1,0,0,1,1,0,0 } , // = 4 { 0,1,0,0,1,0,0 } , // = 5 { 0,1,0,0,0,0,0 } , // = 6 { 0,0,0,1,1,1,1 } , // = 7 { 0,0,0,0,0,0,0 } , // = 8 { 0,0,0,1,1,0,0 } // = 9 }; void setup() { //Initialize all lights up pinMode(dotPin, OUTPUT); //pin 2 pinMode(digit0, OUTPUT); //pin 10 pinMode(digit1, OUTPUT); //pin 11 for(int i=0; i<7; i++) { pinMode(sevenSegmentPins[i], OUTPUT); } digitalWrite(dotPin, HIGH); digitalWrite(digit0, HIGH); digitalWrite(digit1, HIGH); } //Display number void segmentWrite(byte digit) { byte pin = 2; for (byte i=0; i<7; ++i) { digitalWrite(pin, sevenSegment[digit][i]); ++pin; } } void loop() { int n = analogRead(A0); //Read the voltage from AO int vol = n * (5.0 / 1023.0*100); //Use a float type variable to store temperature value which was converted from voltage value //Get the single digits number int sd=vol%10; //Get the ten digits number int td=vol/10; digitalWrite(digit0, LOW); //Turn off ten digits bit digital tube segmentWrite(sd); //Display single digits bit delay(10); //Delay 10ms digitalWrite(digit0, HIGH); //Turn on ten digits bit digital tube digitalWrite(digit1, LOW); //Turn off single digits bit digital tube segmentWrite(td); //Diplay ten digits bit delay(10); //Dealy 10ms digitalWrite(digit1, HIGH); //Turn on single digital tube } Debug Step 1：Copye the cdoe to IDE and compile it Step 2：Set up circuti, as follows： Step 3：Run program Step 4：Observe the digital tube, find a hot object close to the temperature sensor, the value on digital tube will change. Result The temperature sensor closes to the hot object, the value will increase. Video http://v.youku.com/v_show/id_XNjgyMzE4ODg4.html