按键功能

功能按键

实物图如下

• FUN: 可编程按键。按键上电启动SD卡中系统更新文件系统

Linux系统下，此按键可作为常规输入设备。

功能按键的设备节点/dev/input/event0

以下是使用evtest命令测试按键，按下和释放功能。

evtest /dev/input/event0
Input driver version is 1.0.1
Input device ID: bus 0x19 vendor 0x1 product 0x1 version 0x100
Input device name: "gpio-keys"
Supported events:
  Event type 0 (EV_SYN)
  Event type 1 (EV_KEY)
    Event code 257 (BTN_1)
Properties:
Testing ... (interrupt to exit)
Event: time 1651194534.021372, type 1 (EV_KEY), code 257 (BTN_1), value 1
Event: time 1651194534.021372, -------------- SYN_REPORT ------------
Event: time 1651194534.182318, type 1 (EV_KEY), code 257 (BTN_1), value 0
Event: time 1651194534.182318, -------------- SYN_REPORT ------------