Lesson 20--Microduino Two Digital Tube Countdown Display

Language	English

Objective We have learned display the number statically, this lesson will teach you how to dispaly number dynamically. Only need change the code, no hardware change. Equipment Microduino-Core Microduino-FT232R Other hardware equipment Breadboard Jumper one box Breadboard one piece Two digital tube one USB Data cable one Schematic Pin Table Microduino Pin Digital Tube Pin 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 Microduino pin byte digit1 = 11; //Single digit Microduino pin byte dotPin = 2; //Decimal point pin byte sevenSegmentPins[] = {2,3,4,5,6,7,8}; //A,B,C,D,E,F,G 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 9 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() { for(int i=9;i>=0;i--) {// Countdown ten digits for(int j=9;j>=0;j--) {//Countdown to single digit unsigned long startTime = millis(); for (unsigned long elapsed=0; elapsed < 600; elapsed = millis() - startTime) {//Display 600ms digitalWrite(digit0, LOW); //Trun on ten digits tube segmentWrite(j); //Display single tube delay(10); //Delay 10ms digitalWrite(digit0, HIGH); //Turn on ten digits tube digitalWrite(digit1, LOW); //Turn off single tube segmentWrite(i); //Display ten digits delay(10); //Delay 10ms digitalWrite(digit1, HIGH); //Turn on single digit } } } } Debug Step 1：Identify the digitsl tube's Pin Step 2: Copy code to IDE and compile it Step 3: Set up circuit, as follows: Step 4: Run program Setp 5: Observe the digital tube Result The number will countdown from 99 to 0, and then in circle. Video http://v.youku.com/v_show/id_XNjc4NjcxMzY0.html