from machine import Pin, I2C, ADC
import time
import ssd1306

# === Parámetros de configuración ===
sample_rate_hz = 200           # Muestras por segundo (puedes ajustar)
display_window_s = 1.0         # Tiempo visible en pantalla (segundos)
max_pixels = 128               # Ancho en píxeles del OLED

# (para evitar aliasing, según Nyquist: f_máx ≈ sample_rate / 2)

# === Inicialización OLED y ADC ===
i2c = I2C(0, scl=Pin(22), sda=Pin(21))
oled = ssd1306.SSD1306_I2C(128, 64, i2c)

adc = ADC(Pin(15))
adc.atten(ADC.ATTN_11DB)
adc.width(ADC.WIDTH_12BIT)

# === Función para convertir voltaje a coordenada Y en pantalla ===
def voltage_to_y(voltage):
    return int(62 - (voltage / 3.3) * 54) + 8

# === Cálculo de retardo y puntos ===
sleep_time = 1.0 / sample_rate_hz
num_points = int(display_window_s * sample_rate_hz)
if num_points > max_pixels:
    num_points = max_pixels  # limitar al ancho de pantalla

# === Inicializar gráfico y variables ===
oled.fill(0)
oled.vline(0, 8, 56, 1)     # Eje Y
oled.hline(0, 63, 128, 1)   # Eje X
oled.show()

voltages_y = [63] * num_points
last_displayed = -1

# === Bucle principal ===
while True:
    raw = adc.read()
    voltage = (raw / 4095.0) * 3.3
    y = voltage_to_y(voltage)

    voltages_y.pop(0)
    voltages_y.append(y)

    oled.fill_rect(0, 8, 128, 55, 0)

    scale_x = max_pixels / num_points
    for i in range(num_points - 1):
        x1 = int(i * scale_x)
        x2 = int((i + 1) * scale_x)
        y1 = voltages_y[i]
        y2 = voltages_y[i + 1]
        oled.line(x1, y1, x2, y2, 1)

    oled.vline(0, 8, 56, 1)
    oled.hline(0, 63, 128, 1)

    if abs(voltage - last_displayed) > 0.01:
        oled.fill_rect(0, 0, 128, 8, 0)
        oled.text("V = {:.2f} V".format(voltage), 0, 0)
        last_displayed = voltage

    oled.show()
    time.sleep(sleep_time)