# ESP32 and Mycropython: Programming your Hardware
# Author: Mordechai Bar Natan
#
# Lesson 4: Add OLED display
# https://wokwi.com/projects/394060981841594369
#
# Remember:
# On a LED, the long leg is the anode (+). Connect it to pin #2.
# The short leg is the cathode (-). Connect it to GND.
# On a momentary switch (button), connect one side to pin #16 and the other side to GND.
# The display has 4 connections: GND, VCC (to 3.3V), SCL (pin #22) & SDA (pin #21)
#
# References
# https://docs.micropython.org/en/latest/library/machine.Pin.html
# https://docs.micropython.org/en/latest/esp8266/tutorial/ssd1306.html#ssd1306

from machine import Pin, SoftI2C, ADC, PWM
from time import sleep
from ssd1306 import SSD1306_I2C

oled_scl_pin = 22   # Orange cable
oled_sda_pin = 21   # Blue cable
red_led_pin = 2
button_pin = 4

i2c = SoftI2C(scl=Pin(oled_scl_pin), sda=Pin(oled_sda_pin), freq=4000000)
oled_w = 128                                    # display width (0..127)
oled_h = 64                                     # display hight (0..63)

red_led_state = 0
button_state = 0

oled = SSD1306_I2C(oled_w, oled_h, i2c)         # oled will be the display bject
red_led = Pin(red_led_pin, Pin.OUT)
button = Pin(button_pin, Pin.IN, Pin.PULL_UP)

oled.fill(0)                                    # clear the display
oled.text('RED LED OFF', 10, 10)                # initial status
oled.show()                                     # show the display

# toggle the LED when the button is pressed and display LED status
while True:
    last_state = button_state
    button_state = button.value()
    if button_state == 0 and last_state == 1:
        red_led_state = not(red_led_state)
        red_led.value(red_led_state)
        oled.fill(0)
        if red_led.value() == True:
            oled.text('RED LED ON', 10, 10)
        else:
            oled.text('RED LED OFF', 10, 10)
        oled.show()
    sleep(0.1)