显示器亮度自动调节套装

auto_brightness.py

import math
import queue
import threading
import serial
from vcp import * # https://github.com/dot-osk/monitor_ctrl
import logging

# Init VCP
try:
    monitors = enumerate_monitors()
except OSError as err:
    exit(1)
phy_monitors = []
while not phy_monitors:
    for i in monitors:
        try:
            monitor = PhyMonitor(i)
        except OSError as err:
            logging.error(err)
            continue
        phy_monitors.append(monitor)
pm = phy_monitors[0]

# Init serial port
connected = False
port = 'COM6'
baud = 9600
try:
    serial_port = serial.Serial(port, baud, timeout=0)
except serial.serialutil.SerialException:
    logging.error('Can not open serial port.')

# Init lux queue
queue_len = 5
lux_queue = queue.Queue(queue_len)

def handle_data(data):
    global lux_queue
    if data.startswith('Light') and data.endswith('lx'):
        # Parse lux value
        brightness_lx = float(data[7:-3])
        # Slide window average
        if lux_queue.qsize() < queue_len:
            lux_queue.put(brightness_lx)
            return
        else:
            lux_queue.get()
            lux_queue.put(brightness_lx)
        lux_list = list(lux_queue.queue)
        lux_centered_average = (sum(lux_list) - max(lux_list) - min(lux_list)) / (len(lux_list) - 2)
        # control core
        now_brightness = pm.brightness
        ctl_factor = math.log(lux_centered_average+1) * 21
        final_result = 1
        if ctl_factor <= 0:
            pass
        elif ctl_factor >= 100:
            final_result = 100
        else:
            final_result = math.floor(ctl_factor) + 3
        if now_brightness != final_result:
            pm.brightness = final_result
        print(f'Sensor: {brightness_lx} lx Avg: {lux_centered_average:.2f} lx Factor: {ctl_factor:.2f} Display: {now_brightness}->{final_result}')

def read_from_port(ser):
    global connected
    while not connected:
        connected = True
        while True:
            while serial_port.in_waiting:
                try:
                    reading = ser.readline().decode().strip()
                    handle_data(reading)
                except KeyboardInterrupt:
                    ser.close()

thread = threading.Thread(target=read_from_port, args=(serial_port,))
thread.start()

BH1750_CTL.ino

#include <Wire.h>
#include <BH1750.h>

BH1750 lightMeter;

void setup(){
  Serial.begin(9600);
  // Initialize the I2C bus (BH1750 library doesn't do this automatically)
  // On esp8266 devices you can select SCL and SDA pins using Wire.begin(D4, D3);
  Wire.begin();
  if (lightMeter.begin(BH1750::CONTINUOUS_HIGH_RES_MODE)) {
    Serial.println(F("BH1750 Advanced begin"));
  }
  else {
    Serial.println(F("Error initialising BH1750"));
  }
}

void loop() {
  float lux = lightMeter.readLightLevel();
  Serial.print("Light: "+lux+"lx");
  Serial.print(lux);
  Serial.println(" lx");
  delay(250);
}

硬件需求：

• 下位机： ESP8266（25 CNY 左右） 或者 STM32F103C8T6（16 CNY 左右（需要另外买一个 USB2TTL））（已安装 STM32duino Bootloader）
• 传感器： BH1750（5 CNY 包邮）
• 连接线： microUSB x1、母对母杜邦线 10cm若干
• 显示器： 支持 DDC/CI 控制亮度

硬件连接：

• 注意：BH1750 需连接在 STM32F103C8T6 的 I2C1 上（反正就两组，试一下就好了）

程序需要改动的地方：

1. Python 脚本 L26： 修改为你开发板的 COM 口序号（*inx 系统上不可用（自行将 VCP 换成 ddcutil 即可））
2. Python 脚本 L53： 21 为我这估算的参数，即最大环境亮度 55lx 时对应最大亮度。算法为：100/(ln(55)+1)+1≈21

执行方法：

1. 烧录好 Arduino 程序
2. 将开发板连接 PC，记下 COM 口名称
3. 修改 Python 脚本
4. 坐等亮度随环境光变动