from machine import Pin, I2C
import framebuf
import time

class SSD1306_I2C(framebuf.FrameBuffer):
    
    def __init__(self, width, height, i2c, addr=0x3C):
        self.width= width
        self.height= height
        self.i2c= i2c
        self.addr= addr
        self.pages= height//8
        self.buffer= bytearray(self.pages * width)
        super().__init__(self.buffer, width, height, framebuf.MONO_VLSB)
        self.init_display()

    def write_cmd(self, cmd):
        self.i2c.writeto(self.addr, b'\x80' + bytes([cmd]))

    def init_display(self):
        for cmd in(
            0xAE,
            0x20, 0x00,
            0x40,
            0xA1,
            0xA8, self.height - 1,
            0xC8,
            0xD3, 0x00,
            0xDA, 0x12,
            0xD5, 0x80,
            0x81, 0xFF,
            0xA4,
            0xA6,
            0x8D, 0x14, 
            0xAF 
        ):
            self.write_cmd(cmd)
        self.fill(0)
        self.show()

    def show(self):
        self.write_cmd(0x21)
        self.write_cmd(0)
        self.write_cmd(self.width - 1)
        self.write_cmd(0x22)
        self.write_cmd(0)
        self.write_cmd(self.pages - 1)
        self.i2c.writeto(self.addr, b'\x40' + self.buffer)

i2c=I2C(0, scl=Pin(22), sda=Pin(21))
oled=SSD1306_I2C(128, 64, i2c)

oled.text("ESP32 OLED",0 , 0)
oled.text("MicroPython",0 , 12)
oled.text("Hello World!",0 , 24)
oled.show()
while True:
    time.sleep(1)