物联网开发笔记（6）- 使用Wokwi仿真树莓派Pico实现按键操作

这篇文章和大家一起来看下按键相关的操作。

一、目的

使用按键来控制LED不同的闪烁速度

 

二、硬件连接方法

方法一：

LED连接GPIO的端口0，按键连接GPIO的端口1。按键通过一个上拉电阻接到3.3V电源上，当按键不按下时是高信号，按键按下时GPIO端口1导通，变为低信号。

方法二：

去电上拉电阻，使用GPIO的PULL_UP功能。

三、代码分析

方法一：

mian.py

# 这个例子是实现按键操作
from machine import Pin
import utime
 
LED = Pin(0, Pin.OUT)  # 紫色LED，端口0
KEY = Pin(1, Pin.IN)  # 按键，端口1，配置成IN模式
 
while True:
    if KEY.value()== 0:  # 按键按下
        #LED每秒闪烁一次
        LED.value(1)  # LED亮
        utime.sleep(1)
        LED.value(0) # LED灭
        utime.sleep(1)
    else:
      #LED每0.2秒闪烁一次
        LED.value(1)  # LED亮
        utime.sleep(0.2)
        LED.value(0) # LED灭
        utime.sleep(0.2)
 
# 按键使用小技巧：按住Ctrl键然后按下按键后不会弹起。

diagram.json

{
  "version": 1,
  "author": "Anonymous maker",
  "editor": "wokwi",
  "parts": [
    {
      "type": "wokwi-pi-pico",
      "id": "pico",
      "top": -84.04,
      "left": -21.65,
      "attrs": { "env": "micropython-20220117-v1.18" }
    },
    {
      "type": "wokwi-resistor",
      "id": "r1",
      "top": -150.16,
      "left": 11.36,
      "rotate": 180,
      "attrs": { "value": "470" }
    },
    {
      "type": "wokwi-led",
      "id": "led2",
      "top": -160.43,
      "left": -47.75,
      "attrs": { "color": "blue" }
    },
    {
      "type": "wokwi-resistor",
      "id": "r2",
      "top": -139.09,
      "left": 120.03,
      "rotate": 90,
      "attrs": { "value": "470" }
    },
    {
      "type": "wokwi-pushbutton",
      "id": "btn1",
      "top": -63.85,
      "left": -188.55,
      "attrs": { "color": "green", "key": "1" }
    }
  ],
  "connections": [
    [ "led2:A", "pico:GP0", "green", [ "v0" ] ],
    [ "led2:C", "r1:2", "green", [ "v12.49", "h-27.74", "v-75.2", "h106.23" ] ],
    [ "r1:1", "pico:GND.8", "green", [ "v0" ] ],
    [ "btn1:1.r", "pico:GP1", "green", [ "v0" ] ],
    [ "btn1:1.r", "r2:1", "green", [ "v-138.22", "h33.03" ] ],
    [ "r2:2", "pico:3V3", "green", [ "h1.94", "v65.96" ] ],
    [ "btn1:2.r", "pico:GND.4", "green", [ "h0.8", "v99.76" ] ]
  ]
}

方法二：

mian.py

# 这个例子是实现按键操作
from machine import Pin
import utime
 
LED = Pin(0, Pin.OUT)  # 紫色LED，端口0
KEY = Pin(1, Pin.IN, Pin.PULL_UP)  # 按键，端口1，配置成IN和PULL_UP
 
while True:
    if KEY.value()== 0:  # 按键按下
        #LED每秒闪烁一次
        LED.value(1)  # LED亮
        utime.sleep(1)
        LED.value(0) # LED灭
        utime.sleep(1)
    else:
      #LED每0.2秒闪烁一次
        LED.value(1)  # LED亮
        utime.sleep(0.2)
        LED.value(0) # LED灭
        utime.sleep(0.2)
 
# 按键使用小技巧：按住Ctrl键然后按下按键后不会弹起。

diagram.json

{
  "version": 1,
  "author": "Anonymous maker",
  "editor": "wokwi",
  "parts": [
    {
      "type": "wokwi-pi-pico",
      "id": "pico",
      "top": -84.04,
      "left": -21.65,
      "attrs": { "env": "micropython-20220117-v1.18" }
    },
    {
      "type": "wokwi-resistor",
      "id": "r1",
      "top": -150.16,
      "left": 11.36,
      "rotate": 180,
      "attrs": { "value": "470" }
    },
    {
      "type": "wokwi-led",
      "id": "led2",
      "top": -160.43,
      "left": -47.75,
      "attrs": { "color": "blue" }
    },
    {
      "type": "wokwi-pushbutton",
      "id": "btn1",
      "top": -63.85,
      "left": -188.55,
      "attrs": { "color": "green", "key": "1","label": "Btn1", "bounce": "0"  }
    }
  ],
  "connections": [
    [ "led2:A", "pico:GP0", "green", [ "v0" ] ],
    [ "led2:C", "r1:2", "green", [ "v12.49", "h-27.74", "v-75.2", "h106.23" ] ],
    [ "r1:1", "pico:GND.8", "green", [ "v0" ] ],
    [ "btn1:1.r", "pico:GP1", "green", [ "v0" ] ],
    [ "btn1:2.r", "pico:GND.4", "green", [ "h0.8", "v99.76" ] ]
  ]
}

关于按键的更多知识请查看：

wokwi-pushbutton Reference | Wokwi Docs12mm Tactile Switch Button (momentary push button).https://docs.wokwi.com/parts/wokwi-pushbutton

好了关于树莓派Pico的延时到此结束了，后面我们换个开发板，跟大家继续讲述新的知识，谢谢！