Arduino UNO 学习 （三） 4x4薄膜按键、9G舵机、超声波传感器、人体传感器、1位数码管、四位数码管

（一） 4×4薄膜按键

代码如下：

const int numRows = 4;
const int numCols = 4;
const int debounceTime = 20;
const char keymap[numRows][numCols] = {
  {'1','2','3','A'},
  {'4','5','6','B'},
  {'7','8','9','C'},
  {'*','0','#','D'}
};
const int rowPins[numRows] = {4,5,6,7};
const int colPins[numCols] = {8,9,10,11};

void setup() { // all keymap level = HIGH
  // put your setup code here, to run once:
  Serial.begin(9600);
  for(int row = 0; row < numRows; row++){
    pinMode(rowPins[row], INPUT);  //输入
    digitalWrite(rowPins[row], HIGH);  //上拉电阻，
  }
  for(int column = 0; column < numCols; column++){
    pinMode(colPins[column], OUTPUT);  //写出，只有列能写（8，9，10，11）口
    digitalWrite(colPins[column], HIGH);
  }
}

void loop() {
  // put your main code here, to run repeatedly:
  char key = getkey();
  if(key != 0){
    Serial.print("Got key ");
    Serial.println(key);
  }
}

char getkey(){
  char key = 0;
  for(int column = 0; column < numCols; column++){  //列
    digitalWrite(colPins[column], LOW);
    for(int row = 0; row < numRows; row++){
      if(digitalRead(rowPins[row]) == LOW){  // touch keyboard ?
        delay(debounceTime);
        while(digitalRead(rowPins[row]) == LOW){
          key = keymap[row][column];
        }
      }
    }
    digitalWrite(colPins[column], HIGH);
  }
  return key;
}

           

（二） 9G舵机

代码

#include <Servo.h>
Servo myservo;

void setup() {
  // put your setup code here, to run once:
  myservo.attach(9);
}

void loop() {
  // put your main code here, to run repeatedly:
  for(int pos = 0; pos < 180; pos++){
    myservo.write(pos);
    delay(15);
  }
  for(int pos = 180; pos >= 1; pos--){
    myservo.write(pos);
    delay(15);  
  }  
}

（三） 超声传感器

代码

const int trig = 8;
const int echo = 9;

void setup() {
  // put your setup code here, to run once:
  pinMode(trig, OUTPUT);
  pinMode(echo, INPUT);
  Serial.begin(9600);
}

void loop() {
  // put your main code here, to run repeatedly:
  long IntervalTime = 0;
  while(1){
    digitalWrite(trig, HIGH);
    delayMicroseconds(15);
    digitalWrite(trig, LOW);
    IntervalTime = pulseIn(echo, HIGH);
    float S = IntervalTime/58.00;
    Serial.println(S);
    S = 0; IntervalTime = 0;
    delay(500);
  }
}

（四） 人体传感器

代码

int ledpin = 12;
int inpin = 13;
int buttonState;

void setup() {
  // put your setup code here, to run once:
  pinMode(ledpin, OUTPUT);
  pinMode(inpin, INPUT);
  Serial.begin(9600);
}

void loop() {
  // put your main code here, to run repeatedly:
  buttonState = digitalRead(inpin);
  
  if(buttonState == HIGH){
    digitalWrite(ledpin, HIGH);
    delay(100);
    buttonState = digitalRead(inpin);

    if(buttonState == LOW){
      digitalWrite(ledpin, LOW);
      Serial.println(buttonState);
    }
  }
}

（五） 1位数码管

代码

int LEDCount = 8;
const unsigned char dofly_DuanMa[16] = {0x3f,0x06,0x5b,0x4f,0x66,
                                        0x6d,0x7d,0x07,0x7f,0x6f,
                                        0x77,0x7c,0x39,0x5e,0x79,0x71};
int LEDPins[] = {0,1,2,3,4,5,6,7};

void setup() {
  // put your setup code here, to run once:
  for(int i = 0; i < LEDCount; i++){
    pinMode(LEDPins[i], OUTPUT);
  }
}

void deal(unsigned char value){
  for(int i = 0; i < 8; i++){
    digitalWrite(LEDPins[i], bitRead(value, i));
  }
}

void loop() {
  // put your main code here, to run repeatedly:
  for(int i = 0; i < 16; i++){
    deal(dofly_DuanMa[i]);
    delay(1000);
  }
}

（六） 四位数码管

int LEDCount = 8;
int SEGCount = 4;
long previousMillis = 0;
const unsigned char dofly_DuanMa[16] = {0x3f,0x06,0x5b,0x4f,0x66,
                                        0x6d,0x7d,0x07,0x7f,0x6f,
                                        0x77,0x7c,0x39,0x5e,0x79,0x71};
int LEDPins[] = {12,8,5,3,2,11,6,4};
int SegPins[] = {13,10,9,7};
unsigned char displayTemp[4];

void setup() {
  // put your setup code here, to run once:
  for(int i = 0; i < LEDCount; i++){
    pinMode(LEDPins[i], OUTPUT);
  }
  for(int j = 0; j < SEGCount; j++){
    pinMode(SegPins[j], OUTPUT);
    //digitalWrite(SegPins[j], HIGH);
  }
}

void deal(unsigned char value){
  for(int i = 0; i < 8; i++){
    digitalWrite(LEDPins[i], bitRead(value, i));
    //bitRead(value, i);
  }
}

// Static code
//void loop() {
//  // put your main code here, to run repeatedly:
//  
//  static unsigned int num;
//  static unsigned long lastTime = 0;
//
//  if(millis() - lastTime >= 1000){
//    lastTime = millis();
//    num++;
//  }
//
//  // static display 1 2 3 4
//  displayTemp[0] = dofly_DuanMa[1];
//  displayTemp[1] = dofly_DuanMa[2];
//  displayTemp[2] = dofly_DuanMa[3];
//  displayTemp[3] = dofly_DuanMa[4];
//
//  static int i = 0;
//  unsigned long currentMillis = millis();
//
//  if(currentMillis - previousMillis > 0){
//    previousMillis = currentMillis;
//    deal(0);
//   
//    for(int a = 0; a < 4; a++){
//      digitalWrite(SegPins[a], HIGH);
//    }
//    
//    digitalWrite(SegPins[i], LOW);
//    deal(displayTemp[i]);
//    delay(500);
//    i++;
//    if(i == 4) { i = 0; }
//  }
//}

// Dynamic code
void loop() {
  // put your main code here, to run repeatedly:
  
  static unsigned int num;
  static unsigned long lastTime = 0;

  if(millis() - lastTime >= 1000){
    lastTime = millis();
    num++;
  }

  // static display 1 2 3 4
  displayTemp[0] = dofly_DuanMa[num/1000];
  displayTemp[1] = dofly_DuanMa[(num%1000)/100];
  displayTemp[2] = dofly_DuanMa[((num%1000)%100)/10];
  displayTemp[3] = dofly_DuanMa[((num%1000)%100)%10];

  static int i = 0;
  unsigned long currentMillis = millis();

  if(currentMillis - previousMillis > 0){
    previousMillis = currentMillis;
    deal(0);
   
    for(int a = 0; a < 4; a++){
      digitalWrite(SegPins[a], HIGH);
    }
    
    digitalWrite(SegPins[i], LOW);
    deal(displayTemp[i]);
    i++;
    if(i == 4) { i = 0; }
  }
}

总结：

（1）舵机不能转到逆时针的180°，不知道是不是机器的原因；

（2）四位数码管，位引脚低电位有效。

（3）总的来说，代码仔细点，保证硬件有效连接，都还是可以完成的！