import time, utime
from machine import Pin, time_pulse_us, I2C
import ssd1306

i2c=I2C(0, scl=Pin(21), sda=Pin(20))
oled_width = 128
oled_height = 64
oled = ssd1306.SSD1306_I2C(oled_width, oled_height, i2c)
oled.fill(0)
oled.show()

def rst_oled():
    oled.fill(0)
    oled.show()
    now = time.localtime()
    title = "{:02d}/{:02d}/{} {:02d}:{:02d}".format(now[2], now[1], now[0], now[3], now[4], now[5])
    #title = "Home Info"
    oled.text(title, center_txt(title), 2)
    oled.show()

def center_txt(txt):
    x = (oled_width - len(txt) * 8) // 2
    return x

rst_oled()