市售的溫度感測器，有電源導通，但D13一直收不到信號〈黃色LED沒亮〉，代碼如下
#define DO 13
void setup() {
// put your setup code here, to run once:
Serial.begin(115200);
Serial.println("Temp test!");
pinMode(13, INPUT);
}
void loop()
{
delay(2000);
// put your main code here, to run repeatedly:
float t = digitalRead(DO);
Serial.print(" Temperature: ");
Serial.println(t);
}