Arduino UNO、温度センサー、LEDで気温を表示する

温度センサーLM35DZを使用する。0〜100度まで測定可能
温度センサーの+Vs端子にArduino5V, Voutをアナログ端子(A0〜A5)、GNDにGNDを接続する

アナログ端子は、HIGH/LOW間の1.0V、1.6V、2.0V、2.5V、3.1V…の細かい電圧を読み取れる
読み取った0~5Vの電圧は、0〜1023の値として取得できる。
35だった場合、
35/1023 = 0.034
0.034 * 5 = 0.17V
1V = 100℃
0.17 * 100 = 17℃

#define TERMINAL_A 3
#define TERMINAL_B 4
#define TERMINAL_C 5
#define TERMINAL_D 6
#define TERMINAL_F 7
#define TERMINAL_G 8
#define TERMINAL_H 9
#define TACT_SW 10  // 10番ピンをタクトスイッチ
#define DIGIT_1 11
#define DIGIT_10 12
#define DIGIT_100 13
#define DIGIT_1000 14
#define DP 15 // ドット
#define THERMO_IN 16  // A2端子のため16を指定

byte counter = 0;  // Arduinoで使用できる1byteの型
byte state = 0;
byte state_old = 0;
byte buf_num = 0;
int thermo_buf[10];

void led_output(byte num){

  switch(num) {
      case 0:  // 4桁7セグメントではアノードコモンを使用しており、7セグメントLEDの逆
      digitalWrite(TERMINAL_A, LOW);
      digitalWrite(TERMINAL_B, LOW);
      digitalWrite(TERMINAL_C, LOW);
      digitalWrite(TERMINAL_D, HIGH);
      digitalWrite(TERMINAL_F, LOW);
      digitalWrite(TERMINAL_G, LOW);
      digitalWrite(TERMINAL_H, LOW);
      break;
      case 1:
      digitalWrite(TERMINAL_A, LOW);
      digitalWrite(TERMINAL_B, HIGH);
      digitalWrite(TERMINAL_C, HIGH);
      digitalWrite(TERMINAL_D, HIGH);
      digitalWrite(TERMINAL_F, LOW);
      digitalWrite(TERMINAL_G, HIGH);
      digitalWrite(TERMINAL_H, HIGH);
      break;
      case 2:
      digitalWrite(TERMINAL_A, LOW);
      digitalWrite(TERMINAL_B, LOW);
      digitalWrite(TERMINAL_C, HIGH);
      digitalWrite(TERMINAL_D, LOW);
      digitalWrite(TERMINAL_F, HIGH);
      digitalWrite(TERMINAL_G, LOW);
      digitalWrite(TERMINAL_H, LOW);
      break;
      case 3:
      digitalWrite(TERMINAL_A, LOW);
      digitalWrite(TERMINAL_B, LOW);
      digitalWrite(TERMINAL_C, HIGH);
      digitalWrite(TERMINAL_D, LOW);
      digitalWrite(TERMINAL_F, LOW);
      digitalWrite(TERMINAL_G, LOW);
      digitalWrite(TERMINAL_H, HIGH);
      break;
      case 4:
      digitalWrite(TERMINAL_A, LOW);
      digitalWrite(TERMINAL_B, HIGH);
      digitalWrite(TERMINAL_C, LOW);
      digitalWrite(TERMINAL_D, LOW);
      digitalWrite(TERMINAL_F, LOW);
      digitalWrite(TERMINAL_G, HIGH);
      digitalWrite(TERMINAL_H, HIGH);
      break;
      case 5:
      digitalWrite(TERMINAL_A, HIGH);
      digitalWrite(TERMINAL_B, LOW);
      digitalWrite(TERMINAL_C, LOW);
      digitalWrite(TERMINAL_D, LOW);
      digitalWrite(TERMINAL_F, LOW);
      digitalWrite(TERMINAL_G, LOW);
      digitalWrite(TERMINAL_H, HIGH);
      break;
      case 6:
      digitalWrite(TERMINAL_A, HIGH);
      digitalWrite(TERMINAL_B, LOW);
      digitalWrite(TERMINAL_C, LOW);
      digitalWrite(TERMINAL_D, LOW);
      digitalWrite(TERMINAL_F, LOW);
      digitalWrite(TERMINAL_G, LOW);
      digitalWrite(TERMINAL_H, LOW);
      break;
      case 7:
      digitalWrite(TERMINAL_A, LOW);
      digitalWrite(TERMINAL_B, LOW);
      digitalWrite(TERMINAL_C, HIGH);
      digitalWrite(TERMINAL_D, HIGH);
      digitalWrite(TERMINAL_F, LOW);
      digitalWrite(TERMINAL_G, HIGH);
      digitalWrite(TERMINAL_H, HIGH);
      break;
      case 8:
      digitalWrite(TERMINAL_A, LOW);
      digitalWrite(TERMINAL_B, LOW);
      digitalWrite(TERMINAL_C, LOW);
      digitalWrite(TERMINAL_D, LOW);
      digitalWrite(TERMINAL_F, LOW);
      digitalWrite(TERMINAL_G, LOW);
      digitalWrite(TERMINAL_H, LOW);
      break;
      case 9:
      digitalWrite(TERMINAL_A, LOW);
      digitalWrite(TERMINAL_B, LOW);
      digitalWrite(TERMINAL_C, LOW);
      digitalWrite(TERMINAL_D, LOW);
      digitalWrite(TERMINAL_F, LOW);
      digitalWrite(TERMINAL_G, LOW);
      digitalWrite(TERMINAL_H, HIGH);
      break;

      default:
      digitalWrite(TERMINAL_A, HIGH);
      digitalWrite(TERMINAL_B, HIGH);
      digitalWrite(TERMINAL_C, HIGH);
      digitalWrite(TERMINAL_D, LOW);
      digitalWrite(TERMINAL_F, HIGH);
      digitalWrite(TERMINAL_G, HIGH);
      digitalWrite(TERMINAL_H, HIGH);
      break;  
    }      
}



void setup() {
  // 初期化
  pinMode(TERMINAL_A, OUTPUT);
  pinMode(TERMINAL_B, OUTPUT);
  pinMode(TERMINAL_C, OUTPUT);
  pinMode(TERMINAL_D, OUTPUT);
  pinMode(TERMINAL_F, OUTPUT);
  pinMode(TERMINAL_G, OUTPUT);
  pinMode(TERMINAL_H, OUTPUT);
  pinMode(DP, OUTPUT);

  pinMode(DIGIT_1, OUTPUT);
  pinMode(DIGIT_10, OUTPUT);
  pinMode(DIGIT_100, OUTPUT);
  pinMode(DIGIT_1000, OUTPUT);
  
  pinMode(TACT_SW, INPUT); // タクトスイッチに接続した10番ピンをインプットに設定
  pinMode(THERMO_IN, INPUT); // 16番ピンをINPUT指定

  digitalWrite(DIGIT_1, LOW);
  digitalWrite(DIGIT_10, LOW);
  digitalWrite(DIGIT_100, LOW);
  digitalWrite(DIGIT_1000, LOW);

  led_output(counter);
}

void clear_num(void){
  digitalWrite(TERMINAL_A, HIGH);
  digitalWrite(TERMINAL_B, HIGH);
  digitalWrite(TERMINAL_C, HIGH);
  digitalWrite(TERMINAL_D, HIGH);
  digitalWrite(TERMINAL_F, HIGH);
  digitalWrite(TERMINAL_G, HIGH);
  digitalWrite(TERMINAL_H, HIGH);
  digitalWrite(DP, HIGH);
}

int get_temperature(void){

    float thermo_sens;
    int thermo;
    int thermo_ave = 0;
    byte i;

    thermo_sens = analogRead(THERMO_IN); // センサー値取得
    thermo_sens = ((5*thermo_sens)/1024) * 100; // 温度へ変換
    thermo = thermo_sens * 10;

    thermo_buf[buf_num] = thermo;  // 初期値は0
    buf_num++;
    if(buf_num > 9){
      buf_num = 0;
    }

    for(i = 0; i < 10; i++){
      thermo_ave = thermo_ave + thermo_buf&#91;i&#93;;
    }
    thermo_ave = thermo_ave / 10;

    return thermo_ave;
}

void loop() {

  int num;
  int thermo;
  state = digitalRead(TACT_SW);  // 電流が流れているとHIGH, 流れていないとLOW

  if((state == HIGH) && (state_old == LOW)){
      counter++;
  } else {
  }

  if(counter >= 10000){
    counter = 0;
  }

  thermo = get_temperature();
  num = thermo/ 1000;
  clear_num();
  digitalWrite(DIGIT_1000, HIGH);
  delay(1);
  led_output(num);
  delay(5);
  digitalWrite(DIGIT_1000, LOW);

  num = thermo % 1000;
  num = thermo/ 100;
  clear_num();
  digitalWrite(DIGIT_100, HIGH);
  delay(1);
  led_output(num);
  delay(5);
  digitalWrite(DIGIT_100, LOW);

  num = thermo % 100;
  num = num/ 10;
  clear_num();
  digitalWrite(DIGIT_10, HIGH);
  delay(1);
  led_output(num);
  delay(5);
  digitalWrite(DIGIT_10, LOW);

  num = thermo % 10;
  clear_num();
  digitalWrite(DIGIT_1, HIGH);
  delay(1);
  led_output(num);
  delay(5);
  digitalWrite(DIGIT_1, LOW);
  
  state_old = state;

}

配線

あれ、コンパイルして転送したら、突然シリアルポートを読み込まなくなった。
なんだこれ。

一瞬パニクったが、温度センサーの配線が間違っていた模様。表裏をひっくり返して再度実行

mde

出来ました。
Arduinoは中々良い買い物だった。