from machine import Pin, I2C,ADC
import ssd1306
import time
# ESP32 Pin assignment 
i2c = I2C(0, scl=Pin(22), sda=Pin(21))

oled_width = 128
oled_height = 64
oled = ssd1306.SSD1306_I2C(oled_width, oled_height, i2c)


oled.pixel(5, 5,5)
oled.show()
oled.fill(0)
time.sleep_ms(1000)
oled.pixel(15, 5,5)
led=Pin(12, Pin.OUT)
led.value(1)
photon=ADC(Pin(27))
photon.atten(ADC.ATTN_11DB)       #Full range: 3.3v
oled.show()
# Define grid size
grid_size = 30
while True:
    oled.fill(0)
     # Map the voltage value to a pixel intensity (0 to grid_size)
      # Draw the grid
    voltage = (photon.read() / 4095) * 3.3  # Calculate voltage
    pixel_intensity = int((voltage / 3.3) * grid_size)
    for x in range(grid_size):
        for y in range(grid_size):
            if x + y < pixel_intensity:
                oled.pixel(x * (oled_width // grid_size), y * (oled_height // grid_size), 1)

    oled.text('Voltage: {:.2f}V'.format(voltage), 40, 10)
    oled.show()
    time.sleep_ms(500)