使用Arduino串口打开LED。 我怎么了

Question

void setup(){
    Serial.begin(9600);
    pinMode(13, OUTPUT);
}

void loop() {
    if (Serial.available() > 0){
       int inChar = Serial.read();
       if (inChar == 'H'){
           digitalWrite(13, HIGH);
       }
       if (inChar == 'L'){
        digitalWrite(13, LOW); 
       }
    }
}

I have seen very similar programs. I don't get any compile errors, but the led light won't turn on. Is there an error in my code? Thanks

Answer 1

Sounds like a hardware issue. Double check that first.

Answer 2

Use a digital multimeter (DMM) to read the voltage between pin 13 and Arduino ground. It should output 5V when you send the 'H'. If it does, then your problem is the LED. If it does not output 5V when you send the 'H' then you have a software or serial communication issue.

Double check that you have the correct BAUD rate and COM port settings in whatever program is talking to the Arduino.