Raspberry Pi GPIO输入始终为高

Question

我使用的是：rpi-gpio (v2)
硬件：Raspberry Pi 3 b +

仅当我向GPIO pin 38按下按钮时，我才发送高电平

我是一个名为server.js的文件，其中包含我设置的pin_ins数组：

let pins = [38];
for (var i = =; i < pins.length; i++) {
    gpio.setup(pins[i], gpio.DIR_IN, gpio.EDGE_BOTH);
} 

之后，我使用on更改事件侦听器：

gpio.on('change', function(pin, value) {
   if(value) {
      console.log('Pin:', pin, 'is set to', value);
   }
});

当我使用以下脚本运行脚本时：sudo DEBUG=rpi-gpio node server.js，我得到的结果是：

Channel 38 value is now false
rpi-gpio read pin 20 with value 0 +1ms
rpi-gpio emitting change on channel 38 with value false +1ms
Channel 38 value is now false
rpi-gpio read pin 20 with value 0 +1ms
rpi-gpio emitting change on channel 38 with value false +0ms
Channel 38 value is now false
rpi-gpio read pin 20 with value 0 +1ms
rpi-gpio emitting change on channel 38 with value false +1ms
Channel 38 value is now false
rpi-gpio read pin 20 with value 1 +1ms
rpi-gpio emitting change on channel 38 with value true +0ms
Channel 38 value is now true
rpi-gpio read pin 20 with value 1 +1ms
rpi-gpio emitting change on channel 38 with value true +0ms
Channel 38 value is now true
rpi-gpio read pin 20 with value 0 +1ms
rpi-gpio emitting change on channel 38 with value false +0ms
Channel 38 value is now false
rpi-gpio read pin 20 with value 1 +1ms
rpi-gpio emitting change on channel 38 with value true +0ms
Channel 38 value is now true
[....]

我在做什么错？