from machine import Pin, PWM, I2C
from lcd1602 import LCD
import time

# --- 測定対象の距離範囲（cm） ---
MIN_DIST = 1
MAX_DIST = 50

# --- 白鍵15音（C4〜C6） ---
white_keys = [
    ("C4", 261), ("D4", 294), ("E4", 330), ("F4", 349), ("G4", 392),
    ("A4", 440), ("B4", 494), ("C5", 523), ("D5", 587), ("E5", 659),
    ("F5", 698), ("G5", 784), ("A5", 880), ("B5", 988), ("C6", 1047)
]

# --- 超音波センサー設定 ---
trig = Pin(17, Pin.OUT)
echo = Pin(16, Pin.IN)

# --- スピーカーPWM設定 ---
speaker = PWM(Pin(15))
speaker.duty_u16(0)

# --- LCD設定 ---
i2c = I2C(1, sda=Pin(18), scl=Pin(19), freq=400000)
lcd = LCD(i2c)
lcd.message("Distance Piano\n   Loading...")
time.sleep(2)
lcd.clear()

# --- 距離を測る関数 ---
def measure_distance():
    trig.low()
    time.sleep_us(2)
    trig.high()
    time.sleep_us(10)
    trig.low()

    while echo.value() == 0:
        pass
    start = time.ticks_us()

    while echo.value() == 1:
        pass
    end = time.ticks_us()

    duration = time.ticks_diff(end, start)
    dist_cm = duration * 0.0343 / 2
    return max(MIN_DIST, min(MAX_DIST, dist_cm))

# --- 距離 → 音階変換 ---
def distance_to_note(cm):
    step = (MAX_DIST - MIN_DIST) / (len(white_keys) - 1)
    index = int((cm - MIN_DIST) / step)
    index = max(0, min(len(white_keys) - 1, index))
    return white_keys[index]

# --- メインループ ---
try:
    last_lcd_update = time.ticks_ms()

    while True:
        dist = measure_distance()
        note_name, freq = distance_to_note(dist)

        # 音を更新（リアルタイム）
        speaker.freq(freq)

        # LCDの表示は0.5秒おきに更新
        now = time.ticks_ms()
        if time.ticks_diff(now, last_lcd_update) >= 500:
            lcd.clear()
            lcd.message("Dist:{:.1f}cm\nNote:{} ({}Hz)".format(dist, note_name, freq))
            last_lcd_update = now

        time.sleep(0.1)

# --- 停止処理 ---
finally:
    speaker.duty_u16(0)
    lcd.clear()
    lcd.message("Stopped")
    time.sleep(1)
    lcd.closelight()