LED - Revision history

FabienM: Redirecting to GPIO LEDS

2012-07-10T13:35:19Z

Redirecting to GPIO LEDS

Jorasse: Replacing page with 'see GPIO_LEDS'

2012-07-10T09:17:10Z

Replacing page with 'see GPIO_LEDS'

FabienM: /* Switch led with user button */

2012-07-10T07:48:52Z

‎Switch led with user button

FabienM: /* Blinking */

2012-07-10T07:47:46Z

‎Blinking

FabienM at 07:37, 10 July 2012

2012-07-10T07:37:23Z

FabienM at 07:35, 10 July 2012

2012-07-10T07:35:52Z

FabienM: New page: == The linux LED driver class == On recent kernel, linux have a led driver. This led can be driven from /sys/class/leds/ directory. For APF28Dev, the led is configurable under the direc...

2012-07-10T07:34:59Z

New page: == The linux LED driver class == On recent kernel, linux have a led driver. This led can be driven from /sys/class/leds/ directory. For APF28Dev, the led is configurable under the direc...

New page

== The linux LED driver class ==

On recent kernel, linux have a led driver. This led can be driven from /sys/class/leds/ directory.

For APF28Dev, the led is configurable under the directory :

<pre class="apf">
# cd /sys/class/leds/apfdev:green:user
</pre>

=== Blinking ===

The blinking style can be selected with ''trigger'' file. By defaut on APF28Dev, Heartbeat is selected :

<pre class="apf">
# cat /sys/class/leds/apfdev:green:user/trigger
none nand-disk mmc0 timer [heartbeat] backlight gpio default-on
</pre>

Blinking style can be changed with ''echo'' command :

<pre class="apf">
# echo "nand-disk" > /sys/class/leds/apfdev:green:user/trigger
</pre>

With this "nand-disk" option selected, the led will blink each time nand access occur (try with ''sync'' command to see it blinking).

← Older revision		Revision as of 13:35, 10 July 2012
Line 1:		Line 1:
−	~~see~~ [[GPIO_LEDS]]	+	#REDIRECT [[GPIO_LEDS]]

@@ Line 30: / Line 30: @@
 === Switch led with user button ===
-It is possible to switch led state using the APF28Dev user button. This button is seen as gpio17 under Linux, then configure the led trigger as gpio :
+It is possible to switch led state using the APF28Dev user button. This button is seen as gpio17 (as seen under APF28Dev [[datasheet]]) under Linux, then configure the led trigger as gpio :
 <pre class="apf">

@@ Line 27: / Line 27: @@
 With this "nand-disk" option selected, the led will blink each time nand access occur (try with ''sync'' command to see it blinking).
 === Links ===
 See the kernel documentation [http://www.mjmwired.net/kernel/Documentation/leds-class.txt Documentation/leds-class.txt] for more information about this driver.

← Older revision		Revision as of 07:37, 10 July 2012
Line 27:		Line 27:

	With this "nand-disk" option selected, the led will blink each time nand access occur (try with ''sync'' command to see it blinking).		With this "nand-disk" option selected, the led will blink each time nand access occur (try with ''sync'' command to see it blinking).
		+
		+	=== Links ===
		+
		+	See the kernel documentation [http://www.mjmwired.net/kernel/Documentation/leds-class.txt Documentation/leds-class.txt] for more information about this driver.

@@ Line 1: / Line 1: @@
-== The linux LED driver class ==
+see [[GPIO_LEDS]]
-−
-On recent kernel, linux have a led driver. This led can be driven from /sys/class/leds/ directory.
-−
-For APF28Dev, the led is configurable under the directory :
-−
-<pre class="apf">
- # cd /sys/class/leds/apfdev:green:user
-</pre>
-−
-=== Blinking ===
-−
-The blinking style can be selected with ''trigger'' file. By defaut on APF28Dev, Heartbeat is selected :
-−
-<pre class="apf">
-# cat /sys/class/leds/apfdev:green:user/trigger
-none nand-disk mmc0 timer [heartbeat] backlight gpio default-on
-</pre>
-−
-Blinking style can be changed with ''echo'' command :
-−
-<pre class="apf">
-# echo "nand-disk" > /sys/class/leds/apfdev:green:user/trigger
-# cat /sys/class/leds/apfdev:green:user/trigger
-none [nand-disk] mmc0 timer heartbeat backlight gpio default-on
-</pre>
-−
-With this "nand-disk" option selected, the led will blink each time nand access occur (try with ''sync'' command to see it blinking).
-−
-=== Switch led with user button ===
-−
-It is possible to switch led state using the APF28Dev user button. This button is seen as gpio17 (as seen under APF28Dev [[datasheet]]) under Linux, then configure the led trigger as gpio :
-−
-<pre class="apf">
-# echo "gpio" > /sys/class/leds/apfdev:green:user/trigger
-</pre>
-−
-New config files are available :
-<pre class="apf">
-# ls /sys/class/leds/apfdev:green:user/
-brightness          gpio                power               uevent
-desired_brightness  inverted            subsystem
-device              max_brightness      trigger
-</pre>
-−
-Then the trigger gpio can be configured with ''gpio'' file :
-−
-<pre class="apf">
-# echo 17 > gpio
-</pre>
-−
-Then pushing the user switch will now commute the LED state.
-−
-=== Links ===
-−
-See the kernel documentation [http://www.mjmwired.net/kernel/Documentation/leds-class.txt Documentation/leds-class.txt] for more information about this driver.