Test wifi connectivity

twc.py

import machine
import network
import time

# because we use onbaord GPIO, we invert the meaning of the pin
# so 0 turns it on, 1 turn it off
pin = machine.Pin(16, machine.Pin.OUT)
def poff(): pin.value(1)
def pon(): pin.value(0)
poff()

def tmain1():
    wlan = network.WLAN(network.STA_IF)
    try:
        while True:
            wlan.active(True)
            try:
                nets = wlan.scan()
                pon()
            except OSError:
                poff()
            wlan.active(False)
            time.sleep_ms(500)
    finally:
        poff()
        wlan.active(False)

tmain1()

This project tests to see if there's a Wifi connection within range. It is useful if you want to know if your device will be able to attach to a Wifi point, or if it is out of range.

The code is written in MicroPython for a nodemcu/ESP8226/etc.. Notes:

• Transfer the file across to your ncodemcu.
• in main.py add the line import tcw. You can, alternatively, run the program in uPython's repl, although you will probably want to try the device disconnected from your computer
• Ensure that that nothing is attached to GPIO16 (aka D0), as the onboard LED is used to display the status of the connection
• Power the device. The pic below shows 6V connected, with positive connected to Vin, and negative connected to GND. A 9V battery will also work. Alternative powering methods may also work
• Roam around to see if there is a network. The LED will be lit if there is a network, and unlit otherwise. Allow a little time for the device to settle. It sometimes take a little while for scans to complete, and there is a 0.5s delay between scans.

The picture belows shows a setup. The LED is alight, demonstrating that there is Wifi within connectivity distance.