Re: Web server In/out + physical button control via gpio
Posted: Sat May 01, 2021 11:18 am
Interesting. I'm sure you're right about it being easily done, but for web programming n00bs like myself it would be good to see a code example 
Code: Select all
try:
import asyncio
except:
import uasyncio as asyncio
import network
from uasyncio.stream import Server
from femtoweb import FemtoWeb
from machine import Pin
app = FemtoWeb()
@app.route('/')
async def index(http_req):
""" index.html """
http_req.start_response()
repl_vars["{{button_placeholder}}"] = button_html % ""
await http_req.render_file("index.html", repl_vars)
@app.route('/update')
async def update(http_req):
""" update """
global ledState, repl_vars
ledState = not ledState
if ledState:
ledstate = "checked"
else:
ledstate = ""
http_req.start_response()
repl_vars["{{button_placeholder}}"] = button_html % ledstate
await http_req.render_file("index.html", repl_vars)
@app.route('/state')
async def state(http_req):
""" state """
http_req.start_response()
if ledState:
http_req.ws.write(b"1")
else:
http_req.ws.write(b"0")
await http_req.ws.drain()
async def main():
try:
wlan = network.WLAN(network.STA_IF) # create station interface
print(wlan.ifconfig()[0])
await Server()._serve(app.handle, '0.0.0.0', 80, 8)
except:
server = await asyncio.start_server(app.handle, '127.0.0.1', 80)
async with server:
await server.serve_forever()
async def switch():
global ledState
while True:
await asyncio.sleep(0)
if but.value() == 0:
ledState = not ledState
await asyncio.sleep(1)
async def loop():
while True:
led.value(not ledState)
await asyncio.sleep(0)
led = Pin(2, Pin.OUT)
but = Pin(4, Pin.IN, Pin.PULL_UP)
ledState = True
ledstate = ""
button_html = '''<h4>Output - GPIO 2 - State <span id="outputState"></span></h4><label class="switch"><input type="checkbox" onchange="toggleCheckbox(this)" id="output" %s ><span class="slider"></span></label>'''
repl_vars = {}
asyncio.create_task(loop())
asyncio.create_task(switch())
asyncio.run(main())
1. Copy the htmlcode (See link in start of topic) to a file called 'index.html' The only thing changed is that %BUTTONPLACEHOLDER% is replaced by {{button_placeholder}} (the placeholder for the html button code)
2. put index.html on your Python device.
I tested it on a esp8266 and it works more or less as expected. So led can be controlled by button on website or switch. And if it is toggled by the hardware switch the website will show the state.
One final thing. I used my own webserver (FemtoWeb, because it is stripped down to the bottom). It is some work in progress, but I'm sure that if you use PicoWeb, you can do something similar.