toggle_HS_client_SSD1306_power_save.py

'''
This sketch uses a momentary push button to toggle between hotspot and wifi client modes
based on a user defined config file which holds the config for the wifi hotspot and wifi
client networks, it uses the SSD1306 128x32 display to show the current system state but
make sure adafruit_blinka is first installed:
https://learn.adafruit.com/circuitpython-on-raspberrypi-linux/circuitpython-raspi
and then proceed to follow the steps to install the SSD1306 here after switching into the venv****:
https://learn.adafruit.com/monochrome-oled-breakouts/python-setup
I also used .bashrc to autostart the python virtual environment so I could run this code at boot.

All the best, stay creative and have fun :)
-techscapades
'''

'''==========================================SETUP=========================================='''
# define time variables
import time
connection_sleep_time = 10
poll_time = 1
error_to_exit_time = 10
oled_on_time = 20

# import all the SSD 1306 stuff
import board
import digitalio
from PIL import Image, ImageDraw, ImageFont
import adafruit_ssd1306
oled_reset = digitalio.DigitalInOut(board.D4)
WIDTH = 128
HEIGHT = 32
BORDER = 5
i2c = board.I2C()
oled = adafruit_ssd1306.SSD1306_I2C(WIDTH, HEIGHT, i2c, addr=0x3C, reset=oled_reset)
font = ImageFont.load_default()
oled.fill(0)
oled.show()
image = Image.new("1", (oled.width, oled.height))
draw = ImageDraw.Draw(image)
draw.text((0,0), "Initialising", font=font, fill=255,)
draw.text((0,12), "WiFi <=> Hotspot", font=font, fill=255,)
oled.image(image)
oled.show()

#define atexit behaviour
import atexit
def force_exit():
	oled.fill(0)
	oled.show()
	image = Image.new("1", (oled.width, oled.height))
	draw = ImageDraw.Draw(image)
	draw.text((0,0), "EXITING", font=font, fill=255,)
	oled.image(image)
	oled.show()
	time.sleep(5)
	oled.fill(0)
	oled.show()
atexit.register(force_exit)

# try to read the from path/to/config_file.txt and populate command f-strings
config_filename = '/home/rpz21/python/toggle_HS_client_config.txt'
config = {}
try:
	with open(config_filename, 'r') as file:
		lines = file.readlines()
	for line in lines:
		line = line.strip()
		if line:
			key, value = line.split('=',1)
			config[key.strip()] = value.strip()
	hotspot_SSID = config.get('hotspot_SSID')
	hotspot_PW = config.get('hotspot_PW')
	start_hs_cmd = f"sudo nmcli d wifi hotspot ifname wlan0 ssid {hotspot_SSID} password {hotspot_PW}"
	wifi_SSID = config.get('wifi_SSID')
	wifi_PW = config.get('wifi_PW')
	stop_hs_start_wifi_cmd = f"sudo nmcli con down id {hotspot_SSID} && sudo nmcli d wifi connect {wifi_SSID} password {wifi_PW}"
	start_wifi_cmd = f"sudo nmcli d wifi connect {wifi_SSID} password {wifi_PW}"
	default_mode = config.get('default_mode')
	button_pin = config.get('button_pin')
	config_read_success = True
	time.sleep(5)
except:
	error_code = f'config file: {config_filename} not found, exiting within 60 seconds'
	print(error_code)
	message = "config file not found!"
	config_read_success = False
	image = Image.new("1", (oled.width, oled.height))
	draw = ImageDraw.Draw(image)
	oled.fill(0)
	oled.show()
	draw.text((0,0), message, font=font, fill=255,)
	oled.image(image)
	oled.show()
	time.sleep(error_to_exit_time)
	exit()

# import Button class from gpiozero and define pin to attach button to
from gpiozero import Button
button_pin = int(button_pin) # following gpio definition
button = Button(button_pin)
# optional booleans for complex control
switched_modes = True
button_pressed = False

# get the current ip address and determine which mode system is currently in
import socket
import os
def get_ip_address(interface):
	try:
        	# Get the IP address associated with the given interface
        	ip_address = os.popen(f'ip addr show {interface}').read().split("inet ")[1].split("/")[0]
        	return ip_address
	except IndexError:
	        return None

interface = 'wlan0'
ip_address = get_ip_address(interface)

def check_if_hs_active(ip_address):
	# use the return value in LOOP
	if ip_address == '10.42.0.1' or ip_address =='10.42.0.255':
		return True
	else:
		return False

# set the system into user defined default state from config file
import subprocess
# *********** modes are defined as: 1 for wifi, 2 for hotspot ************
if ip_address == '10.42.0.1' or ip_address =='10.42.0.255':
	# change the 10.x.x.x to whatever your hotspot IP is, use 'ifconfig' command in terminal to find out
        current_mode = 2
else:
        current_mode = 1
default_mode = int(default_mode)
print(f"default mode: {default_mode}")
print(f"current mode: {current_mode}")
if current_mode != default_mode:
	if current_mode == 1:
		print('setting current mode from 1 to 2')
		process = subprocess.Popen(start_hs_cmd, shell=True, stdout=subprocess.PIPE,stderr=subprocess.PIPE,text=True)
	elif current_mode == 2:
		print('setting current mode from 2 to 1')
		process = subprocess.Popen(stop_hs_start_wifi_cmd, shell=True, stdout=subprocess.PIPE,stderr=subprocess.PIPE,text=True)
	time.sleep(connection_sleep_time)
if check_if_hs_active(get_ip_address(interface)):
        current_mode = 2
else:
        current_mode = 1
if current_mode == 2:
	current_SSID = hotspot_SSID
else:
	current_SSID = wifi_SSID
print(f"current mode: {current_mode}")
message = f"current mode: {current_mode}"
image = Image.new("1", (oled.width, oled.height))
draw = ImageDraw.Draw(image)
draw.text((0,0), message, font=font, fill=255,)
draw.text((0,12), current_SSID, font=font, fill=255,)
oled.image(image)
oled.show()

'''==========================================LOOP=========================================='''
print(f'Polling button pin: gpio-{button_pin}')
start_time = time.time()
oled_switched = False
print(start_time)
while True:
	if button.is_pressed and oled_switched == True:
		if check_if_hs_active(get_ip_address(interface)):
			current_mode = 2
		else:
			current_mode = 1
		print(f"current mode: {current_mode}")
		# update OLED
		if current_mode == 2:
			current_SSID = hotspot_SSID
		else:
			current_SSID = wifi_SSID
		image = Image.new("1", (oled.width, oled.height))
		draw = ImageDraw.Draw(image)
		oled.fill(0)
		oled.show()
		message = f"current mode: {current_mode}"
		draw.text((0,0), message, font=font, fill=255,)
		draw.text((0,12), current_SSID, font=font, fill=255,)
		oled.image(image)
		oled.show()
		time.sleep(0.5)
		start_time = time.time()
		oled_switched = False
		continue
	if button.is_pressed and oled_switched == False:
		switched_modes = False
		button_pressed = True
		start_time = time.time()
		oled_switched = False
	if not switched_modes and button_pressed:
		# this if statement isn't necessary but I included it for my own control
		image = Image.new("1", (oled.width, oled.height))
		draw = ImageDraw.Draw(image)
		#oled.fill(0)
		#oled.show()
		#time.sleep(1)
		message = "toggling modes"
		draw.text((0,12), message, font=font, fill=255,)
		oled.image(image)
		oled.show()
		print("toggling modes")
		# toggle the modes from wifi client to hotspot
		if current_mode == 1:
			process = subprocess.Popen(start_hs_cmd, shell=True, stdout=subprocess.PIPE,stderr=subprocess.PIPE,text=True)
		else:
			process = subprocess.Popen(stop_hs_start_wifi_cmd, shell=True, stdout=subprocess.PIPE,stderr=subprocess.PIPE,text=True)
		# give some debounce for the button
		time.sleep(connection_sleep_time)
		# check what the current mode it
		if check_if_hs_active(get_ip_address(interface)):
        		current_mode = 2
		else:
        		current_mode = 1
		print(f"current mode: {current_mode}")
		# update OLED
		if current_mode == 2:
        		current_SSID = hotspot_SSID
		else:
        		current_SSID = wifi_SSID
		image = Image.new("1", (oled.width, oled.height))
		draw = ImageDraw.Draw(image)
		oled.fill(0)
		oled.show()
		time.sleep(1)
		message = f"current mode: {current_mode}"
		draw.text((0,0), message, font=font, fill=255,)
		draw.text((0,12), current_SSID, font=font, fill=255,)
		oled.image(image)
		oled.show()
		# reset variables
		switched_modes = True
		button_pressed = False
	# change this to reduce the reactiveness
	time.sleep(poll_time)
	# print(time.time())
	if time.time() - start_time >= oled_on_time and oled_switched == False:
		oled.fill(0)
		oled.show()
		oled_switched = True