Dormant and wake with deinit and pin 23

[ravra]

As with many others, I'm looking to run my picoW on batteries in a loop where it goes dormant, wakes up via a pin, and then uses Wifi to send an email. I grabbed code from lots of googling and it mostly all works except for a one thing.

If I just use the wlan.deinit call when shutting down Wifi before going dormant, the power drops down to about 10mA and the loop stays healthy:

def disconnWifi(wlan):
    print("Disabling Wifi")
    wlan.disconnect()
    wlan.active(False)
    wlan.deinit()     # Removing this drops power to under 1mA
    time.sleep(1)
    Pin(23, Pin.OUT).low()
    time.sleep(1)

However, if I REMOVE the wlan.deinit, the power drops to under 1mA - big difference. However, upon wake, I bring pin 23 high but Wifi doesn't start up properly, with the last print being "Enabling Wifi." I've read conflicting accounts of how power for the Wifi module (cyw43) is controlled with some saying that it is powered down by the deinit and others saying that pin 23 does it. The docs say that GPIO23 simply controls the Power Save mode of the regulator, directing how the regulator output waveform is modulated. It says GPIO23 should be low by default - i.e. in the Power Save mode - but when I run I see it as high at the start. Confusing.

Maybe the deinit prevents the Power Save mode which keeps the network code from going bonkers when going dormant? Perhaps clocks or something else need to be re-initialized? Anybody understand this stuff?

Complete code:

import network
import time, sys
import umailTest
from   picozero import pico_led
import lowpower
from   machine import Pin

def sendPicoEmail(smtp, recipient_email, email_subject, message):
    sender_name = 'RaspberryPiPico'
    smtp.to(recipient_email)
    smtp.write("From:" + sender_name + "<"+ sender_email+">\n")
    smtp.write("Subject:" + email_subject + "\n\n")
    smtp.write(message + '\n\n')
    smtp.send()
    smtp.myQuit()

def connWifi():
    print("Enabling Wifi")
    ssid = 'mySsid'
    password = 'myPassword'
    Pin(23, Pin.OUT).high()
    time.sleep(3)
    wlan = network.WLAN(network.STA_IF)
    wlan.active(True)
    wlan.connect(ssid, password)

    # Wait for connection to establish
    max_wait = 10
    while max_wait > 0:
        if wlan.status() < 0 or wlan.status() >= 3:
                break
        max_wait -= 1
        print('waiting for connection...')
        time.sleep(1)

    # Manage connection errors
    if wlan.status() != 3:
        raise RuntimeError('Network Connection has failed')
    else:
        print('connected')
    return wlan
        
def disconnWifi(wlan):
    print("Disabling Wifi")
    wlan.disconnect()
    wlan.active(False)
    wlan.deinit()     # Removing this drops power to under 1mA
    time.sleep(1)
    Pin(23, Pin.OUT).low()
    time.sleep(1)
    
    
if __name__ == "__main__":
    sender_email = '[email protected]'
    sender_app_password = 'emailPassword'

    recipient_email = '[email protected]'
    subject         = 'Email from RPi Pico'
    message         = 'Your message \nhere...'

    Pin(15, mode=Pin.IN, pull=Pin.PULL_DOWN) 

    while True:
        pico_led.on()
        wlan = connWifi()
        time.sleep(4)
        print("Creating SMTP connection")
        smtp = umailTest.SMTP('smtp.mail.yahoo.com', 587, ssl=False)
        smtp.login(sender_email, sender_app_password)
        print("Sending email...")
        sendPicoEmail(smtp, recipient_email, subject, message)
        disconnWifi(wlan)
        pico_led.off()
        print("Going dormant")
        lowpower.dormant_until_pin(15)
        time.sleep(5)

If it matters, I'm running this from a stock Thonny (4.1.4) installed a few weeks ago.