The PanGu development board provides two controllable GPIO LED lights (D16, D17). Among them, D16 is used as the heartbeat light of Linux system by default, and can also be configured as user control.
The default trigger mode of the LED light (D16) is heartbeat, which can be controlled by modifying it to none below.

# cd /sys/class/leds/cpu
# echo none > trigger

Light up the LED:

# echo 1 > brightness

Turn off the LED light:

# echo 0 > brightness

Set as heartbeat light trigger:

# cd /sys/class/leds/cpu
# echo heartbeat > trigger