User Manual

For C language users:

Step 2: Open the code file:

cd /home/pi/SunFounder_Super_Kit_V3.0_for_Raspberry_Pi/C

Note: Change directory to the path of the code in this experiment via cd.

Step 3: Compile the Code

gcc 02_buttonControlLed.c -o 02_buttonControlLed -lwiringPi

make 02_buttonControlLed

Step 4: Run the executable file above

sudo ./02_buttonControlLed

Step 5: Check the code

nano 02_buttonControlLed.c

Code Explanation

#define LedPin 0 Pin B17 in the T_Extension Board connects to the GPIO0. GPIO0

corresponds to pin0 in the wiringPi pin figure. So in C program, LedPin is defined as 0.

#define ButtonPin 1 Pin B18 in the T_Extension Board connects to the GPIO8. GPIO8

corresponds to pin1 in the wiringPi pin figure. So in C program, LedPin is defined as 1.

pinMode(LedPin, OUTPUT) Set LedPin as output to assign value to it.

pinMode(ButtonPin, INPUT) Set ButtonPin as input to read the value of ButtonPin.

pullUpDnControl(ButtonPin, PUD_UP) Set the ButtonPin as pull-up input. When the button

is not pressed, the I/O port is 3.3V. When the button is pressed, the I/O port connects

to GND (OV). You can judge the button status by reading the level value of the I/O port.

while(1){

// indicate that button has pressed down

if(digitalRead(ButtonPin) == 0){

// LED on

digitalWrite(LedPin, LOW);

printf("...LED on\n");

}

else{

// LED off

digitalWrite(LedPin, HIGH);

printf("LED off...\n");

}

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