This tutorial deals with how to control onboard leds of Orange Pi Zero.
The Orange Pi Zero has two onboard LEDs, a red one and a green one. You can control them using sysfs interface. In general you can use a sysfs interface of the gpio driver, but since these two leds are reserved by the LED driver you can only use this way.
echo 1 > /sys/class/leds/red_led/brightness
echo 0 > /sys/class/leds/red_led/brightness
echo 1 > /sys/class/leds/green_led/brightness
echo 0 > /sys/class/leds/green_led/brightness