Difference between revisions of "Rock/LED"

Latest revision as of 05:23, 6 January 2015

English

The Radxa Rock has 3 LEDs on board.

LED	GPIO ref.	GPIO number
Green	GPIO0_B4	172
Blue	GPIO0_B6	174
Red	GPIO0_B7	175

All are programmable using either LEDs class devices or GPIOs.

LEDs as class devices

On the latest kernel images (Ubuntu 14.04 server/desktop), the 3 LEDs are configured as LED class devices.

You can control them via /sys/class/leds/

Read the documentation for more information: https://www.kernel.org/doc/Documentation/leds/leds-class.txt

The default status of the three on board leds are:

Red: On when there is power
Green: Flash twice per second after the kernel booting, it's called heartbeat.
Blue: Flash when the uSD card is reading/writing.

You can change the behaviour of each LED by using the echo command on their trigger property.

   root@radxa:~ # echo none > /sys/class/leds/red/trigger
   root@radxa:~ # echo default-on > /sys/class/leds/red/trigger
   root@radxa:~ # echo timer > /sys/class/leds/red/trigger
   root@radxa:~ # echo heartbeat > /sys/class/leds/red/trigger

You can use cat on the trigger property to list all the available values.

   root@radxa:~ # cat /sys/class/leds/red/trigger
   none test_ac-online test_battery-charging-or-full test_battery-charging test_battery-full test_battery-charging-blink-full-solid mmc0 mmc1 timer [heartbeat] backlight gpio default-on sleep rfkill0

Here is the list of current triggers:

none
test_ac-online
test_battery-charging-or-full
test_battery-charging
test_battery-full
test_battery-charging-blink-full-solid
mmc0
mmc1
timer
heartbeat
backlight
gpio
default-on
sleep
rfkill0

The GPIO control external LEDs is moved to GPIO page.

turn off LEDs

use "none" trigger for triggered LEDs or just turn off for non-triggered LEDs.

e.g.

   echo none > /sys/class/leds/blue/trigger
   echo none > /sys/class/leds/green/trigger
   echo 0 > /sys/class/leds/red/brightness

you can modify kernel to change default state at boot.

@@ Line 1: / Line 1: @@
-The RR has 3 LEDs, green(172), blue(174), red(175). All can be programmable.
+{{rock_header}}
+{{Languages| rock/LED}}
+The Radxa Rock has 3  LEDs on board.
+{| class="wikitable" style="width:25%; white-space:nowrap; text-align:center"
+! scope="col" | LED
+! scope="col" | GPIO ref.
+! scope="col" | GPIO number
+|-
+! scope="row" | <span style="color: green;">Green</span>
+| GPIO0_B4 || 172
+|-
+! scope="row" | <span style="color: blue;">Blue</span>
+| GPIO0_B6 || 174
+|-
+! scope="row" | <span style="color: red;">Red</span>
+| GPIO0_B7 || 175
+|}
-Below is program in different languages to flash the green led on RR.
+All are programmable using either LEDs class devices or GPIOs.
 __TOC__
-== c ==
+== LEDs as class devices ==
-<syntaxhighlight lang="c" enclose="div">
-#include <stdio.h>
+On the latest kernel images (Ubuntu 14.04 server/desktop), the 3 LEDs are configured as LED class devices.
-int main()
+You can control them via '''/sys/class/leds/'''
-{
-  FILE *fp = fopen("/sys/class/gpio/export", "w");
-  if( !fp )
-  {
-    printf("error open export file");
-    return 1;
-  }
-  fprintf(fp, "%d", 175);
-  fclose(fp);
-  fp = fopen("/sys/class/gpio/gpio175/direction", "w");
+Read the documentation for more information: https://www.kernel.org/doc/Documentation/leds/leds-class.txt
-  if( !fp )
+The default status of the three on board leds are:
-  {
+* <span style="color: red;">Red</span>: On when there is power
-    printf("error open export file");
+* <span style="color: green;">Green</span>: Flash twice per second after the kernel booting, it's called heartbeat.
-    return 1;
+* <span style="color: blue;">Blue</span>: Flash when the uSD card is reading/writing.
-  }
-  fprintf(fp, "%s", "out");
-  fclose(fp);
-  fp = fopen("/sys/class/gpio/gpio175/value", "w");
+You can change the behaviour of each LED by using the '''echo''' command on their '''trigger''' property.
-  if( !fp )
+    root@radxa:~ # echo none > /sys/class/leds/red/trigger
-  {
+    root@radxa:~ # echo default-on > /sys/class/leds/red/trigger
-     printf("error open export file");
+     root@radxa:~ # echo timer > /sys/class/leds/red/trigger
-     return 1;
+     root@radxa:~ # echo heartbeat > /sys/class/leds/red/trigger
-  }
-  fprintf(fp, "%d", 1);
-}
-</syntaxhighlight>
+You can use '''cat''' on the '''trigger''' property to list all the available values.
-== python ==
+    root@radxa:~ # cat /sys/class/leds/red/trigger
-<syntaxhighlight lang="python" enclose="div">
+    none test_ac-online test_battery-charging-or-full test_battery-charging test_battery-full test_battery-charging-blink-full-solid mmc0 mmc1 timer [heartbeat] backlight gpio default-on sleep rfkill0
-import time
+Here is the list of current triggers:
+* none
+* test_ac-online
+* test_battery-charging-or-full
+* test_battery-charging
+* test_battery-full
+* test_battery-charging-blink-full-solid
+* mmc0
+* mmc1
+* timer
+* heartbeat
+* backlight
+* gpio
+* default-on
+* sleep
+* rfkill0
-def initpin(pinnum, mode):
+'''The GPIO control external LEDs is moved to [[rock/GPIO|GPIO]] page.'''
-  '''
-  pinnum: pin number, eg. 172, 175 etc.
-  mode: pin mode, valid values: in or out
-  '''
-  with open('/sys/class/gpio/export', 'w') as f:
-    f.write(str(pinnum))
-  with open('/sys/class/gpio/gpio' + str(pinnum) + '/direction', 'w') as f:
+== turn off LEDs ==
-    f.write(str(mode))
-def setpin(pinnum, value):
+use "none" trigger for triggered LEDs or just turn off for non-triggered LEDs.
-  with open('/sys/class/gpio/gpio' + str(pinnum) + '/value', 'w') as f:
-    f.write(str(value))
-if __name__ == '__main__':
+e.g.
-  initpin(175, 'out')
-  while True:
-    setpin(175, 0)
-    time.sleep(1)
-    setpin(175, 1)
-    time.sleep(1)
-</syntaxhighlight>
-== shell ==
+    echo none > /sys/class/leds/blue/trigger
-<syntaxhighlight lang="bash" enclose="div">
+    echo none > /sys/class/leds/green/trigger
+    echo 0 > /sys/class/leds/red/brightness
-#!/bin/sh
+you can modify [https://github.com/radxa/linux-rockchip/blob/889bc07b6e62705a8ea04b021db3cc73a786c2d4/arch/arm/mach-rk3188/board-rk3188-box.c#L1330 kernel] to change default state at boot.
-# enable the gpio 172 -> green led
-echo 172 > /sys/class/gpio/export
-# set the direction to output
-echo "out" > /sys/class/gpio/gpio172/direction
-while true;
-do
-echo 0 > /sys/class/gpio/gpio172/value #led on
-sleep 1
-echo 1 > /sys/class/gpio/gpio172/value #led off
-sleep 1
-done
-</syntaxhighlight>
-== LED class and triggers ==
-on radxa-rock/android-kk branch, 3 LEDs are configured as LED class devices. you can control LEDs via /sys/class/leds/.

Difference between revisions of "Rock/LED"

Latest revision as of 05:23, 6 January 2015

Contents

LEDs as class devices

turn off LEDs