# 作业23-在shell控制台、OLED屏上同时显示超声波测距SR04的信息

from machine import Pin, I2C
from ssd1306 import SSD1306_I2C
from time import sleep_us, ticks_us

# ------------------ 硬件初始化 ------------------
# HC-SR04超声波传感器
trigger = Pin(12, Pin.OUT)  # 触发引脚（GPIO12）
echo = Pin(14, Pin.IN)      # 回声引脚（GPIO14）

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

# ------------------ 功能函数 ------------------
def get_distance():
    """获取超声波传感器测量的距离（厘米）"""
    # 触发脉冲
    trigger.value(0)
    sleep_us(2)
    trigger.value(1)
    sleep_us(10)
    trigger.value(0)
    
    # 测量回声时间
    while echo.value() == 0:
        pulse_start = ticks_us()
    while echo.value() == 1:
        pulse_end = ticks_us()
    
    # 计算距离（厘米）
    pulse_duration = pulse_end - pulse_start
    distance = pulse_duration * 0.034 / 2  # 声速340m/s，转换为厘米
    return distance

def display_oled(distance):
    """在OLED显示距离数据"""
    oled.fill(0)
    oled.text("Distance:", 0, 0)
    oled.text(f"{distance:.1f} cm", 0, 20)
    oled.show()

def loop():
    """主循环：同时输出到Shell和OLED"""
    while True:
        distance = get_distance()
        # 1. 输出到Shell控制台
        print(f"Distance: {distance:.1f} cm")
        # 2. 显示到OLED屏
        display_oled(distance)
        sleep_us(500000)  # 500ms测量间隔

# ------------------ 程序入口 ------------------
if __name__ == '__main__':
    loop()