Pico W web server sets an RGB LED

# Set up a web server: the Pico W serves a page on port 80 with four
# links that set the RGB LED (GP13, GP14, GP15) and the temperature from
# the thermistor divider on GP28. Open the board's address from the Web
# panel to see it.
from machine import ADC, Pin
import math
import network
import socket
import time

SSID = "Mokxi-Lab"
PASSWORD = "breadboard"
rgb = [Pin(n, Pin.OUT, value=0) for n in (13, 14, 15)]
sensor = ADC(28)
COLORS = {"/red": (1, 0, 0), "/green": (0, 1, 0), "/blue": (0, 0, 1), "/off": (0, 0, 0)}

def connect(ssid, password):
    wlan = network.WLAN(network.STA_IF)
    wlan.active(True)
    wlan.connect(ssid, password)
    for _ in range(20):                    # give it ten seconds
        if wlan.isconnected():
            return wlan.ifconfig()[0]
        time.sleep_ms(500)
    raise RuntimeError("could not join " + ssid)

def celsius():
    v = sensor.read_u16() / 65535 * 3.3
    r = 10000 * v / (3.3 - v)
    return 1 / (1 / 298.15 + math.log(r / 10000) / 3950) - 273.15

def page(state):
    links = " ".join('<a href="%s">%s</a>' % (p, p[1:]) for p in COLORS)
    return ("<html><body><h1>Pico W</h1><p>LED: %s</p><p>%s</p>"
            "<p>Temperature: %.1f C</p></body></html>") % (state, links, celsius())

ip = connect(SSID, PASSWORD)
server = socket.socket()
server.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
server.bind(("0.0.0.0", 80))
server.listen(1)
print("Serving on http://%s/" % ip)
state = "off"

while True:
    client, _ = server.accept()
    request = client.recv(1024).decode()
    path = request.split(" ")[1] if " " in request else "/"
    path = path.rstrip("?")
    if path in COLORS:
        for led, v in zip(rgb, COLORS[path]):
            led.value(v)
        state = path[1:]
        print("LED", state)
    client.send("HTTP/1.0 200 OK\r\nContent-Type: text/html\r\n\r\n")
    client.send(page(state))
    client.close()