Summary
Tested ARTIK 530 on the GPIO function, implemented the switch to control the LED light on and light off, with successful result.
ARTIK 530 LED and Switch GPIO
For ARTIK 520, the board already implement an LED circuit, so no need to prepare the switch and LED, the GPIO number shows as below,
on-board device
| sysfs Mapping
| Notes
|
SW403
| GPIO 30
| nearest board edge, next to red LED
|
SW404
| GPIO 32
| next to blue LED
|
Red LED
| GPIO 28
| |
Blue LED
| GPIO 38
| |
On the Artick 530 board Switch and LED looks like below,
Blink LED
Follow this Link, you can use Arduino IDE, Python or C to control the LED.
Below shell command can shows controlling the blue LED (GPIO 38). Blue light will light on and off.
[root@artik ~]# echo 38 > /sys/class/gpio/export
[root@artik ~]# echo out > /sys/class/gpio/gpio38/direction
[root@artik ~]# echo 1 > /sys/class/gpio/gpio38/value
[root@artik ~]# echo 0 > /sys/class/gpio/gpio38/value
[root@artik ~]# echo 38 > /sys/class/gpio/unexport
[root@artik
Python code can be downloaded, tested and it’s working properly, here I am using c code below to control the Blue light on and off every one second.
/*
============================================================================
Name : main.c
Author : Xiong HuiLin
Version :
Copyright : No
Description : Hello World in C
============================================================================
*/
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#define HIGH 1
#define LOW 0
#define INPUT 1
#define OUTPUT 0
FILE *fp;
FILE *p=NULL;
int pin_input = 38;
/*
*
* Print a greeting message on standard output and exit.
*
* On embedded platforms this might require semi-hosting or similar.
*
* For example, for toolchains derived from GNU Tools for Embedded,
* to enable semi-hosting, the following was added to the linker:
*
* --specs=rdimon.specs -Wl,--start-group -lgcc -lc -lc -lm -lrdimon -Wl,--end-group
*
* Adjust it for other toolchains.
*
*/
int
main(void)
{
printf("Hello ARM World!" "\n");
char fName[128];
//linux equivalent code "echo 139 > export" to export the port
if ((fp = fopen("/sys/class/gpio/export", "w")) == NULL){
printf("Cannot open export file.\n");
exit(1);
}
fprintf( fp, "%d", pin_input );
fclose(fp);
// linux equivalent code "echo low > direction" to set the port as an input
sprintf(fName, "/sys/class/gpio/gpio%d/direction", pin_input);
if ((fp = fopen(fName, "w")) == NULL){
printf("Cannot open direction file.\n");
exit(1);
}
fprintf(fp, "out");
fclose(fp);
for(int i=0;i<100;i++)
{
sprintf(fName, "/sys/class/gpio/gpio%d/value", pin_input);
p = fopen(fName,"w");
fprintf(p,"%d",1);
sleep(1);
fclose(p);
sprintf(fName, "/sys/class/gpio/gpio%d/value", pin_input);
p = fopen(fName,"w");
fprintf(p,"%d",0);
sleep(1);
fclose(p);
}
p = fopen("/sys/class/gpio/unexport","w");
fprintf(p,"%d",pin_input);
fclose(p);
printf("End1!!!" "\n");
return 0;
}
The result shows as below video,
src="https://www.youtube.com/embed/Ohg8U74f5uU" allowfullscreen="" width="560" height="315">
Use Switch to Control LED
Follow this Link to read the Button / Switch. Below c code to read Switch 403 (pressed status) to light on the Red LED, and read Switch 404 (pressed status) to light off the Red LED.
/*
============================================================================
Name : main.c
Author : Xiong HuiLin
Version :
Copyright : No
Description : Hello World in C
============================================================================
*/
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include <stdbool.h>
#define HIGH 1
#define LOW 0
#define INPUT 1
#define OUTPUT 0
FILE *fp;
FILE *p=NULL;
int pin_input = 38;
/*
*
* Print a greeting message on standard output and exit.
*
* On embedded platforms this might require semi-hosting or similar.
*
* For example, for toolchains derived from GNU Tools for Embedded,
* to enable semi-hosting, the following was added to the linker:
*
* --specs=rdimon.specs -Wl,--start-group -lgcc -lc -lc -lm -lrdimon -Wl,--end-group
*
* Adjust it for other toolchains.
*
*/
bool digitalPinMode(int pin, int dir){
FILE * fd;
char fName[128];
//Exporting the pin to be used
if(( fd = fopen("/sys/class/gpio/export", "w")) == NULL) {
printf("Error: unable to export pin\n");
return false;
}
fprintf(fd, "%d\n", pin);
fclose(fd); // Setting direction of the pin
sprintf(fName, "/sys/class/gpio/gpio%d/direction", pin);
if((fd = fopen(fName, "w")) == NULL) {
printf("Error: can't open pin direction\n");
return false;
}
if(dir == OUTPUT) {
fprintf(fd, "out\n");
} else {
fprintf(fd, "in\n");
}
fclose(fd);
return true;
}
int digitalRead(int pin) {
FILE * fd;
char fName[128];
char val[2];
//Open pin value file
sprintf(fName, "/sys/class/gpio/gpio%d/value", pin);
if((fd = fopen(fName, "r")) == NULL) {
printf("Error: can't open pin value\n");
return false;
}
fgets(val, 2, fd);
fclose(fd);
return atoi(val);
}
bool digitalWrite(int pin, int val) {
FILE * fd;
char fName[128];
// Open pin value file
sprintf(fName, "/sys/class/gpio/gpio%d/value", pin);
if((fd = fopen(fName, "w")) == NULL) {
printf("Error: can't open pin value\n");
return false;
}
if(val == HIGH) {
fprintf(fd, "1\n");
} else {
fprintf(fd, "0\n");
}
fclose(fd);
return true;
}
int
main(void)
{
printf("Hello ARM World!" "\n");
//LED
//– Red LED: sysfs GPIO 28 on ARTIK 530/710
//– Blue LED: sysfs GPIO 38 on ARTIK 530/710
//sysfs GPIO 30 for SW403 (next to board edge, alongside Red LED)
//sysfs GPIO 32 for SW404 (alongside Blue LED)
do {
digitalPinMode(30,INPUT); //INPUT = 1
printf("digitalPinMode(30,INPUT)!" "\n");
if (!digitalRead(30))
{
digitalPinMode(28,OUTPUT); //OUTPUT = 0
digitalWrite(28,HIGH); //HIGH = 1
}
printf("11111111111111111111111111" "\n");
digitalPinMode(32,INPUT);
if (!digitalRead(32))
{
digitalPinMode(28,OUTPUT); //OUTPUT = 0
digitalWrite(28,LOW); //HIGH = 1
}
printf("22222222222222222222222222222" "\n");
}
while(true);
printf("End1!!!" "\n");
return 0;
}
The result is as below video shows,
src="https://www.youtube.com/embed/mAZByDFkiKk" allowfullscreen="" width="560" height="315">
Reference
Samsung ARTIK Pin Programming
Samsung ARTIK Blink an LED
Samsung ARTIK Reading a Button
Samsung ARTIK Programmable Pins
Samsung ARTIK GPIO Header Maps
