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Page 304

import uasyncio
from machine import Pin

async def blink(led, period_ms):
    while True:
        led.on()
        await uasyncio.sleep_ms(5)
        led.off()
        await uasyncio.sleep_ms(period_ms)

async def main(led1, led2):
    uasyncio.create_task(blink(led1, 700))
    uasyncio.create_task(blink(led2, 400))
    await uasyncio.sleep_ms(10_000)

uasyncio.run(main(Pin(22,Pin.OUT), Pin(23,Pin.OUT)))

Page 305

import uasyncio
from machine import Pin
from time import sleep_ms
async def blink(led, period_ms):
    while True:
        led.on()
        await uasyncio.sleep_ms(5)
        led.off()
        await uasyncio.sleep_ms(period_ms)

async def timewaste():
    while True:
        sleep_ms(10)
        await uasyncio.sleep_ms(0)


async def main(led1, led2):
    uasyncio.create_task(blink(led1, 700))
    uasyncio.create_task(blink(led2, 400))
    uasyncio.create_task(timewaste())
    await uasyncio.sleep_ms(10_000)

uasyncio.run(main(Pin(22,Pin.OUT), Pin(23,Pin.OUT)))

Page 307

import uasyncio
from time import sleep_ms
from machine import Pin, Timer
import network

def setup(country, ssid, key):
    network.country(country)
    wifi = network.WLAN(network.STA_IF)
    wifi.active(True)
    wifi.disconnect()
    LED = Pin(2, Pin.OUT)
    LED.on()
    timeout = 20000
    wifi.connect(ssid,key)
    timer = Timer(1)
    timer.init(period=200, mode=Timer.PERIODIC,callback=lambda t:LED.value(not LED.value()))    
    s = network.STAT_IDLE
    while timeout>0:
        print("connecting",s)
        s = wifi.status()
        if s != network.STAT_CONNECTING:
            break
        sleep_ms(100)
        timeout = timeout-100    
    if(s==network.STAT_GOT_IP):
         timer.init(period=1000, mode=Timer.PERIODIC, callback=lambda t:LED.value(not LED.value()))        
    else:
        timer.deinit()
        LED.on()
    return wifi

async def main():
    reader,writer= await uasyncio.open_connection("www.example.com",80)
    request = b"GET /index.html HTTP/1.1\r\nHost:example.org\r\n\r\n"
    writer.write(request)
    await writer.drain()
    print(await reader.read(512))
    reader.close()
wifi=setup(country, ssid, key)
print("Connected")
print(wifi.ifconfig())
uasyncio.run(main())

Page 310



import uasyncio
import network
from machine import Pin, Timer
from time import sleep_ms
import onewire
import ds18x20

def setup(country, ssid, key):
    network.country(country)
    wifi = network.WLAN(network.STA_IF)
    wifi.active(True)
    wifi.disconnect()
    LED = Pin(2, Pin.OUT)
    LED.on()
    timeout = 20000
    wifi.connect(ssid,key)
    timer = Timer(1)
    timer.init(period=200, mode=Timer.PERIODIC,callback=lambda t:LED.value(not LED.value()))    
    s = network.STAT_IDLE
    while timeout>0:
        print("connecting",s)
        s = wifi.status()
        if s != network.STAT_CONNECTING:
            break
        sleep_ms(100)
        timeout = timeout-100    
    if(s==network.STAT_GOT_IP):
         timer.init(period=1000, mode=Timer.PERIODIC, callback=lambda t:LED.value(not LED.value()))        
    else:
        timer.deinit()
        LED.on()
    return wifi

wifi=setup(country, ssid, key)
print("Connected")
print(wifi.ifconfig())

ow = onewire.OneWire(Pin(22))
presence = ow.reset()
if presence:
    print("Device present")
else:
    print("No device")

DS = ds18x20.DS18X20(ow)
roms = DS.scan()

template = """<!DOCTYPE html>
<html>
<head> <title>Temperature</title> </head>
<body> <h1>Current Temperature</h1>
Hello ESP32 Server World <br/>
The Temperature is: <!--#temp--><br/>
</body>
</html>
"""
async def serve_client(reader,writer):
    print("client")
    print(await reader.read(512))
    DS.convert_temp()
    temp = DS.read_temp(roms[0])
    html=template.replace("<!--#temp-->",str(temp))
    headers = ("HTTP/1.1 200 OK\r\n"
            "Content-Type: text/html; charset=UTF-8\r\n"
            "Server:ESP32\r\n"
            f"Content-Length:{len(html)}\r\n\r\n"
            )
    buf = headers.encode("utf-8")+html.encode("utf-8")
    writer.write(buf)
    await writer.drain()
    writer.close()
    await writer.wait_closed()

async def main():
    await uasyncio.start_server(serve_client, '192.168.253.24', 80,backlog=5)
    while True:
        print("heartbeat")
        await uasyncio.sleep(1)

uasyncio.run(main())