LED
发光二极管（LED，Light Emitting Diode）是一种能将电能转化为光能的半导体器件。犀牛派 A1 板载 4 个三色 LED 指示灯（led0 ~ led3），每个指示灯包含红（red）、绿（green）、蓝（blue）三路颜色通道，可用于系统状态指示或用户自定义显示。
准备
- 犀牛派 A1
- 开源工具 gpiod
shell
sudo apt update
sudo apt install gpiod libgpiod2 libgpiod-dev测试
Android：LED 灯控制
bash
aidlux@aidlux:~$ sudo gpioinfo /dev/gpiochip0 | grep led
line 27: unnamed "led2_green" output active-high [used]
line 44: unnamed "led2_blue" output active-high [used]
line 46: unnamed "led3_red" output active-high [used]
line 108: unnamed "led2_red" output active-high [used]
line 112: unnamed "led1_blue" output active-high [used]
line 118: unnamed "led0_green" output active-high [used]
line 122: unnamed "led1_green" output active-high [used]
line 135: unnamed "led3_blue" output active-high [used]
# 控制 LED3 红灯亮
and -s 'echo 1 > /sys/class/new_leds/led3_red/value'
# 控制 LED3 红灯灭
and -s 'echo 0 > /sys/class/new_leds/led3_red/value'
# 注意 led3_green 已经被系统内部占用，无法通过改变 led3_green/value 来控制灯的亮和灭Ubuntu：LED 灯控制
bash
aidlux@aidlux:~$ sudo gpioinfo /dev/gpiochip3 | grep led
line 27: unnamed "led2_green" output active-high [used]
line 44: unnamed "led2_blue" output active-high [used]
line 46: unnamed "led3_red" output active-high [used]
line 108: unnamed "led2_red" output active-high [used]
line 110: unnamed "led0_red" output active-high [used]
line 112: unnamed "led1_blue" output active-high [used]
line 118: unnamed "led0_green" output active-high [used]
line 122: unnamed "led1_green" output active-high [used]
line 135: unnamed "led3_blue" output active-high [used]
line 142: unnamed "led3_green" output active-high [used]
# 执行如下指令，控制 LED 灯
sudo su
cd /sys/class/gpio_userspace
# 控制 LED3 红灯亮
echo 1 > led3_red/value
# 控制 LED3 红灯灭
echo 0 > led3_red/value
# 注意 led3_green 已经被系统内部占用，无法通过改变 led3_green/value 来控制灯的亮和灭