Epp+dis learning road (2) -- blink! twinkle!

The last article finished the programming software and basic program upload , Copied a program to realize onboard LED The control of , Then learn this at the beginning of this article python The language , Let's first look at the program of the previous article ：

import machinepin = machine.Pin(2, machine.Pin.OUT)pin.on()

The first 1 sentence import machine Is load machine modular , Only after loading, can we make ESP32 The pin of .

The first 2 sentence machine.Pin(2, machine.Pin.OUT) Will be 2 No. pin is defined as output pin

The first 3 sentence pin.on() Let this pin output high level , That is to say 3.3V

The control of this pin can also be written as follows ：

pin.value(1) 

They are the same .

Let's start with this LED The light flashes , First modify the procedure as follows ：​​​​​​​

import machine,timepin = machine.Pin(2, machine.Pin.OUT)pin.on()time.sleep(1)pin.off()time.sleep(1)

  It uses time.sleep(1), The meaning of this sentence is also obvious , Is to make ESP32 sleep 1 second , It's actually a delay 1 second , There are several ways to write ：

time.sleep(1)           #  sleep 1 second

time.sleep_ms(500)      #  sleep 500 millisecond

time.sleep_us(10)       #  sleep 10 subtle

Of course use time Function must be loaded before time modular , You can follow me directly machine Back , Add a comma

Click the Green Run button , If you follow the previous article, it should be uploaded quickly , It's really just the ESP32 Inside main.py Covered it , If you just opened the software , The following dialog box will appear

Same choice MicroPython equipment

Then found ESP32 There are already main.py 了 , It's the program of our last class , Now just cover it ！

  Click Yes and it will be uploaded . Then you will find LED It's on 1 second , Then it went out , No flicker . Let's take a look at the program ：

​​​​​​​

pin.on()time.sleep(1)pin.off()time.sleep(1)

open LED, stop 1 second , Then turn it off and then stop 1 second , then ...... No, then . You can see micropython and Arduino The operating mechanism of is somewhat different ,Arduino Will continue to cycle loop() The sentence in , and micropython Only run the main program once . In order to keep it circulating , We have to write a similar loop() The sentence of ：

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import machine,timepin = machine.Pin(2, machine.Pin.OUT)while True:    pin.on()    time.sleep(1)    pin.off()    time.sleep(1)

We added number 3 sentence while True:

    This is a while Loop statement , as long as while The following statement is true , The statements in the function will run circularly , We wrote directly while True: Then it will always be true , The statements in the function will run forever . Note that the statement contained in the function should be blank with the preceding four spaces , This is a python Programming format , stay C Inside is { }, stay python Inside, there are four blank spaces . Go to Baidu by yourself python Basic tutorials for .

  Upload again , this time ESP32 Upper LED It will flash ！