What to do if arduino gives out some kind of krakozyabry?

Question

Arduino

here is the code

void setup()
{
  pinMode(A4, INPUT);
  Serial.begin(9600);

}

void loop()
{
  Serial.println(analogRead(A4));
}

the photoresistor is powered by a 3.3 volt pin
and the serial port gives out some kind of bugs (⸮x⸮x⸮⸮x)
What should I do?

Answer 1

The port speed specified in the line Serial.begin(9600); must be the same as selected in the arduino IDE terminal

Answer 2

First, fill in the standard example from the manual, it should work for sure.
https://www.arduino.cc/en/Tutorial/AnalogReadSerial

Answer 3

Perhaps the wrong quartz is worth

Or set to "0" FUSE-bit CKDIV8.
Try 1200 baud.

Answer 4

The problem is clearly in the wrong port speed. Try installing termite (or any other terminal software with baud rate settings) and set the baud rate to 4800, 5760, 720, 1200. One of them should work. For the test, it is better to output the string ala "test123"