TS-TPC-7990 LEDs
From embeddedTS Manuals
The kernel provides access to control the LEDs using the sysfs:
# Set Red led on
echo 1 > /sys/class/leds/red-led/brightness
# Set Red led off
echo 0 > /sys/class/leds/red-led/brightness
# Set Green led on
echo 1 > /sys/class/leds/green-led/brightness
# Set Green led off
echo 0 > /sys/class/leds/green-led/brightness
The kernel provides various triggers that can be useful for debugging purposes. The trigger for a given LED is in its directory:
echo "heartbeat" > /sys/class/leds/red-led/trigger
Trigger value | LED toggles on |
---|---|
none | Default, no action |
mmc0 | MicroSD card activity |
mmc1 | eMMC activity |
mmc2 | WIFI SDIO activity |
timer | 2hz blink |
oneshot | Blinks after delay. [1] |
heartbeat | Similar to timer, but varies the period based on system load |
backlight | Toggles on FB_BLANK |
gpio | Toggle based on a specified gpio. [2] |
cpu0 | Blink on CPU core 0 activity |
cpu1 | Blink on CPU core 1 activity |
cpu2 | Blink on CPU core 2 activity |
cpu3 | Blink on CPU core 3 activity |
default-on | Only turns on by default. Only useful for device tree. |
transient | Specify on/off with time to turn off. [3] |
flash/torch | Toggle on Camera activation. Not currently used. |
- ↑ See the Kernel documentation for more details
- ↑ When this trigger is set, a "gpio" file appears in the same directory which can be used to specify what GPIO to follow when it blinks
- ↑ See the Kernel documentation for more details