繼電器：信號線接Arduino 10引腳，5伏接麵包板，gnd接麵包板，公共口接330歐電阻上，常開口接麵包板上。

ard：gnd接led陰極，5v接麵包板

led：陽極連在電阻上

Arduino輸出控製

int realy = 10;
void setup() {
// put your setup code here, to run once:
pinMode(realy, OUTPUT);
}
void loop() {
// put your main code here, to run repeatedly:
digitalWrite(realy, HIGH);
delay(1000);
digitalWrite(realy,LOW);
delay(1000);
}