Keyestudio KS0077, Руководство пользователя, Страница: 60 / 142

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Sample Code
The program compiling is simple. An analogRead () Statement can read the value of the interface.
The A/D acquisition of Arduino 328 is in 10 bits, so the value it reads is among 0 to 1023. One
difficulty in this project is to display the value on the screen, which is actually easy to learn.
First, you need to set the baud rate in voidsetup (). Displaying the value is a communication
between Arduino and PC, so the baud rate of the Arduino should match the the one in the PC's
software set up. Otherwise, the display will be messy codes or no display at all.
In the lower right corner of the Arduino software monitor window, there is a button for baud rate
set up. The set up here needs to match the one in the program. The statement in the program is
Serial.begin(); enclosed is the baud rate value, followed by statement for displaying. You can
either use Serial.print() or Serial.println() statement.
//////////////////////////////////////////////////////////
int potpin=0;// initialize analog pin 0
int ledpin=13;// initialize digital pin 13
int val=0;// define val, assign initial value 0
void setup()
{
pinMode(ledpin,OUTPUT);// set digital pin as “output”
Serial.begin(9600);// set baud rate at 9600
}
void loop()
{
digitalWrite(ledpin,HIGH);// turn on the LED on pin 13
delay(50);// wait for 0.05 second
digitalWrite(ledpin,LOW);// turn off the LED on pin 13
delay(50);// wait for 0.05 second
val=analogRead(potpin);// read the analog value of analog pin 0, and assign it to val
Serial.println(val);// display val’s value
}
//////////////////////////////////////////////////////////
Test Result
The Sample Code uses the built-in LED connected to pin 13.
Each time the device reads a value, the LED blinks. When you rotate the potentiometer knob, you
can see the displayed value change. The reading of analog value is a very common function since
most sensors output analog value. After calculation, you can get the corresponding value you
need.
Below figure shows the analog value it reads.