utils_wifi.py

# utils_wifi.py -- Helper functions for wifi
# By @howdymoto / Wright Bagwell
# Inspired by TodBot's circuitpython-tricks: https://github.com/todbot/circuitpython-tricks
# And by Adafruit/Kattni Rembor's CircuitPython Essentials: https://learn.adafruit.com/circuitpython-essentials/circuitpython-essentials
# MIT license

import os
import wifi
import ipaddress

# For readability, some function calls below start by printing this string
# Data printed inside each function indented with \t for readability
CPUTILS_STRING = 'CP UTILS:'
PING_IP = ipaddress.IPv4Address("8.8.8.8")
# This shuould be a small file, since boards have very little RAM.
FILE_DOWNLOAD_URL = "http://wifitest.adafruit.com/testwifi/index.html"


# Connect to Wifi
# If user doesn't specify SSID and password, it's taken from settings.toml
def connect_wifi(
        ssid=os.getenv("CIRCUITPY_WIFI_SSID"),
        password=os.getenv("CIRCUITPY_WIFI_PASSWORD")
    ):
    print(CPUTILS_STRING, "Connecting to WiFi...")

    # If user doesn't specify ssid/pwd in the function call,
    # they should specify it in settings.toml
    if ssid is None or len(ssid) == 0:
        print(
            "\tNo SSID specified\n",
            "\tEither specify in connect_wifi(),\n",
            "\tor specify one in settings.toml\n",
            "\tPlease see https://docs.circuitpython.org/en/latest/docs/environment.html"
        )
        return
    try:
        print("\tSSID:", ssid)
        print("\tpassword:", password)
        wifi.radio.connect(ssid, password)
        print("\tSuccessfully connected")
    except Exception as e:
        print("\tFailed to connect:", e)
    return


# Look for available WiFI networks (SSIDs)
# Sort by RSSI (signal strength)
# Then, print each found SSID and RSSI
# Finally, return an array of SSIDs and RSSIs
def scan_wifi_networks():
    print(CPUTILS_STRING, "Scanning for WiFi networks...")

    networks = []
    for network in wifi.radio.start_scanning_networks():
        networks.append(network)
    wifi.radio.stop_scanning_networks()
    networks = sorted(networks, key=lambda net: net.rssi, reverse=True)
    for network in networks:
        print("\t", network.ssid, "\t\trssi:", network.rssi, "dBm")
    return networks


# Print info about current WiFi network connection to the REPL.
# Then, try a few network operations to verify it's working reliably.
def test_wifi():
    print(CPUTILS_STRING, "Testing Wifi connection...")

    # Don't bother with tests if not connected to Wifi
    if not wifi.radio.enabled:
        print("\tWifi radio disabled")
        return
    if not wifi.radio.connected:
        print("\tNot connected to WiFi")
        return

    # First, print details about the radio and connection
    print("\tIP:", wifi.radio.ipv4_address)
    mac_address_raw = wifi.radio.mac_address
    mac_formatted = '-'.join(['{:02X}'.format(byte) for byte in mac_address_raw])
    print("\tMAC address:", mac_formatted)
    print("\tDNS server:", wifi.radio.ipv4_dns)
    print("\tGateway:", wifi.radio.ipv4_gateway)
    print("\tSubnet:", wifi.radio.ipv4_subnet)
    print("\tAP Authmode:", wifi.radio.ap_info.authmode)
    print("\tAP SSID:", wifi.radio.ap_info.ssid)
    bssid_raw = wifi.radio.ap_info.bssid
    bssid_formatted = '-'.join(['{:02X}'.format(byte) for byte in bssid_raw])
    print("\tAP BSSID:", bssid_formatted)
    print("\tAP Channel:", wifi.radio.ap_info.channel)
    print("\tAP Country:", wifi.radio.ap_info.country)
    print("\tAP RSSI:", wifi.radio.ap_info.rssi)

    # Second, ping PING_IP - the primary DNS server for Google DNS
    ping = wifi.radio.ping(ip=PING_IP)
    if ping is None:
        print("\tCouldn't ping 'google.com' successfully")
    else:
        print("\tPinging 'google.com' took:", ping * 1000, "ms")

    # Third, get some text via HTTP request and print it
    TEXT_URL = "http://wifitest.adafruit.com/testwifi/index.html"
    print("\tHTTP Request from", TEXT_URL)
    import socketpool
    import ssl
    import adafruit_requests
    pool = socketpool.SocketPool(wifi.radio)
    context = ssl.create_default_context()
    requests = adafruit_requests.Session(pool, context)
    try:
        response = requests.get(TEXT_URL)
        if response.content:
            print("\t"+ "HTTP Response successfully received!")
        else:
            print("\t\tSuccessful request, but empty response")
    except Exception as e:
        print("\tFailed to request data from", TEXT_URL, e)


# Download a ~1MB file to test speed
def test_bandwidth():
    print(CPUTILS_STRING, "Testing download bandwidth...")

    # Abort if not connected to Wifi
    if not wifi.radio.enabled:
        print("\tWifi radio disabled")
        return
    if not wifi.radio.connected:
        print("\tNot connected to WiFi")
        return

    import time
    import socketpool
    import ssl
    import adafruit_requests

    pool = socketpool.SocketPool(wifi.radio)
    context = ssl.create_default_context()
    requests = adafruit_requests.Session(pool, context)

    start_time = time.monotonic()
    try:
        print("\tHTTP request:", FILE_DOWNLOAD_URL)
        response = requests.get(FILE_DOWNLOAD_URL)
        print("\tStatus code:", response.status_code)
        print("\tHeaders:")
        for header, value in response.headers.items():
            print(f"\t\t{header}: {value}")

        if response.status_code == 200:
            # Calculate download speed
            end_time = time.monotonic()
            duration = end_time - start_time    # Time taken for download in seconds
            data_length = len(response.content)  # Length of data in bytes
            speed_bps = data_length / duration  # Speed in bytes per second

            print("\tDownloaded", data_length, "bytes in", duration, "seconds.")
            print("\tDownload speed:", speed_bps, "Bytes per second.")
        else:
            print("Failed to download test file. Status code:", response.status_code)
    except Exception as e:
        print("\tHTTP request error:", e)