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+## 元件选型
+
+- 简单任务快速开发：选择 Seeeduino XIAO 作为主控，Arduino 编程。具有一个 I2C 端口。
+- 小型集成传感器：[SHT30-DIS](https://oss.frank14f.online/EEE/16ch-temp-hum/SHT3x-DIS.pdf)，2.5x2.5mm 集成温湿度传感器、ADC、I2C 通讯，最高采样率 10 mps。范围 0～100%RH、-40～125 deg，误差 2%RH、0.2 deg，重复性 0.08%RH、0.04 deg，飘移 0.25%RH/yr、0.03 deg/yr。
+- I2C 多路复用：[TCA9548A](https://oss.frank14f.online/EEE/16ch-temp-hum/tca9548a.pdf)，4x4mm QFN。1-8 双向转换开关，可设置为 8 个地址，可连接 64 个同名设备。
+- 数据传输：16 通道 1.1mm 三芯屏蔽线传输数据和供电，经复用开关汇于主控处理为物理量，通过 USB 串口输出。
+
+<center><img src="./seeed-studio-xiao.png" alt="seeed-studio-xiao" style="width:33%;" /><center>
+
+## PCB 设计
+
+- 精简设计：周围元件种类仅 4 种：2.2k 主上拉电阻、10k 从上拉电阻、1uF 主解耦、100nF 从解耦。
+- 轻薄：传感器基板使用 0.11mm FPC ，总高度 1mm。
+
+<center><img src="./PCB.jpeg" alt="PCB" style="width:33%;" /><img src="./FPC.jpeg" alt="FPC" style="width:33%;" /></center>
+
+## 主控程序
+
+- 初始化：软重置所有通道的传感器。
+- 定时运行：每经过 1000 系统毫秒运行一次采样。
+- 单次拉取模式：发送请求至传感器后等待采样（15ms）回复 6 byte 数据。
+- CRC-8 校验：4 byte 数据通过 2 byte 校验确认传输完整性。
+
+```c++
+// 16ch Temp&Hum by WANG Yanqi
+// Created 4 Jan 2024
+
+#include <Wire.h>
+
+const long interval = 1000; 
+const uint8_t addr_hub[] = {0x70, 0x72};
+const uint8_t addr_sen = 0x44;
+const int size_hub = sizeof(addr_hub)/sizeof(addr_hub[0]);
+unsigned long previousMillis = 0;
+unsigned long currentMillis = 0;
+uint8_t data[6];
+uint8_t data_crc[2];
+float temp;
+float hum;
+
+float fun_temp(float raw);
+float fun_hum(float raw);
+uint8_t crc8(const uint8_t* data, size_t length);
+
+void setup() {
+  Wire.begin();
+  Serial.begin(9600);
+  delay(5000);
+  // Go through all the hubs
+  for (int i = 0; i < size_hub; i++) {
+    // Go through 8 ch. in a hub
+    for (uint8_t ch = 0b00000001; ch != 0; ch = ch << 1) {
+      // Open the ch.
+      Wire.beginTransmission(addr_hub[i]);
+      Wire.write(ch);
+      Wire.endTransmission();
+      // Soft reset sen.
+      Wire.beginTransmission(addr_sen);
+      Wire.write(0x30);
+      Wire.write(0xA2);
+      Wire.endTransmission();
+      delay(100);
+    }
+    // Close all the ch.
+    Wire.beginTransmission(addr_hub[i]);
+    Wire.write(0);
+    Wire.endTransmission();
+  }
+}
+
+void loop() {
+  // Get the current number of milliseconds since the program started
+  currentMillis = millis();
+  if (currentMillis - previousMillis >= interval) {
+    // Go through all the hubs
+    for (int i = 0; i < size_hub; i++) {
+      // Go through 8 ch. in a hub
+      for (uint8_t ch = 0b00000001; ch != 0; ch = ch << 1) {
+        // Open the ch.
+        Wire.beginTransmission(addr_hub[i]);
+        Wire.write(ch);
+        Wire.endTransmission();
+        read_sen(addr_sen, data);
+        // Check temp.
+        data_crc[0] = data[0];
+        data_crc[1] = data[1];
+        if (crc8(data_crc, sizeof(data_crc)) == data[2]) {
+          temp = fun_temp((data[0] << 8) | data[1]);
+        } else {
+          temp = NAN;
+        }
+        // Check hum.
+        data_crc[0] = data[3];
+        data_crc[1] = data[4];
+        if (crc8(data_crc, sizeof(data_crc)) == data[5]) {
+          hum = fun_hum((data[3] << 8) | data[4]);
+        } else {
+          hum = NAN;
+        }
+        // Print data
+        Serial.print(temp);
+        Serial.print(",");
+        Serial.print(hum);
+        if (i != size_hub-1 || ch != 0b10000000) {
+          Serial.print(";");
+        }
+      }
+      // Close all the ch.
+      Wire.beginTransmission(addr_hub[i]);
+      Wire.write(0);
+      Wire.endTransmission();
+    }
+    Serial.print("\n");
+    previousMillis = currentMillis;
+  }
+}
+
+void read_sen(uint8_t addr, uint8_t* data) {
+  // Clock stretching, high repeatability
+  Wire.beginTransmission(addr);
+  Wire.write(0x2C);
+  Wire.write(0x06);
+  Wire.endTransmission();
+  Wire.requestFrom(addr, 6);
+  for (int i = 0; i < 6; i++) {
+      data[i] = Wire.read();
+  }
+}
+
+uint8_t crc8(const uint8_t* data, size_t length) {
+  // Start with 0xFF for initialization
+  uint8_t crc = 0xFF;
+  for (size_t i = 0; i < length; ++i) {
+    crc ^= data[i];
+    // Loop over each bit
+    for (uint8_t j = 8; j; --j) {
+      // If the uppermost bit is 1...
+      if (crc & 0x80) { 
+        // ... shift left and XOR with the polynomial
+        crc = (crc << 1) ^ 0x31; 
+      } else {
+        // Otherwise, just shift left
+        crc <<= 1; 
+      }
+    }
+  }
+  // No final XOR
+  return crc;
+}
+
+float fun_temp(float raw) {
+  float temp = -45.0 + 175.0 * raw / 65535;
+  return temp;
+}
+
+float fun_hum(float raw) {
+  float hum = 100.0 * raw / 65535;
+  return hum;
+}
+```
+
+## 上位程序
+
+- 创建图形界面：使用 matplotlib 的 pyplot、widgets 实时显示数据和按钮。
+- 读取数据：等待串口输出一行，记录主机时间戳，存入数组。
+- 存储数据：关闭窗口后，将所有数据以 CSV 格式保存。
+
+```python
+# pip install pyserial matplotlib pandas
+
+import serial
+import matplotlib.pyplot as plt
+import pandas as pd
+from matplotlib.widgets import Button
+from datetime import datetime
+
+max_points = 20  # Number of points to display on the graph
+data = {
+    'Timestamp': [],
+    **{f'Temp{i+1}': [] for i in range(16)},
+    **{f'Hum{i+1}': [] for i in range(16)}
+}
+
+# Initialize plots
+plt.ion()
+fig, (ax_temp, ax_hum) = plt.subplots(2, 1, figsize=(15, 10))
+
+# Set plot titles and labels
+ax_temp.set_title('Temperature')
+ax_temp.set_xlabel('Time')
+ax_temp.set_ylabel('Temperature (°C)')
+
+ax_hum.set_title('Humidity')
+ax_hum.set_xlabel('Time')
+ax_hum.set_ylabel('Humidity (%)')
+
+# Global flag to control the data collection
+collecting_data = False
+exit_flag = False
+
+# Button callback functions
+def start_button_callback(event):
+    global collecting_data
+    collecting_data = True
+
+def exit_button_callback(event):
+    global exit_flag
+    exit_flag = True
+
+# Create the buttons
+ax_start_button = plt.axes([0.7, 0.05, 0.1, 0.075])
+ax_exit_button = plt.axes([0.81, 0.05, 0.1, 0.075])
+
+start_button = Button(ax_start_button, 'Start')
+start_button.on_clicked(start_button_callback)
+
+exit_button = Button(ax_exit_button, 'Exit')
+exit_button.on_clicked(exit_button_callback)
+
+# Display the plot window
+plt.show(block=False)
+
+# Wait here until 'Start' button is pressed
+while not collecting_data:
+    plt.pause(0.1)  # Use a short pause to handle UI events
+    if exit_flag:
+        plt.close(fig)
+        raise SystemExit
+
+# Main loop
+try:
+    # Set up the serial connection (adjust the COM port as needed)
+    ser = serial.Serial('/dev/cu.usbmodem14101', 9600, timeout=1)
+    while not exit_flag:
+        line = ser.readline().decode('utf-8').strip()
+        if line:
+            try:
+                # Split the line into groups and then into temperature and humidity values
+                groups = line.split(';')
+                if len(groups) == 16:
+                    timestamp = datetime.now().strftime('%H:%M:%S')
+                    data['Timestamp'].append(timestamp)
+                    temps = []
+                    hums = []
+                    for i, group in enumerate(groups):
+                        temp, hum = map(float, group.split(','))
+                        temps.append(temp)
+                        hums.append(hum)
+                        data[f'Temp{i+1}'].append(temp)
+                        data[f'Hum{i+1}'].append(hum)
+
+                    # Update temperature graph with latest 20 points
+                    ax_temp.clear()
+                    ax_temp.set_title('Temperature')
+                    ax_temp.set_xlabel('Time')
+                    ax_temp.set_ylabel('Temperature (°C)')
+                    for i in range(16):
+                        ax_temp.plot(data['Timestamp'][-max_points:], data[f'Temp{i+1}'][-max_points:], label=f'Temp{i+1}')
+                    
+                    # Update humidity graph with latest 20 points
+                    ax_hum.clear()
+                    ax_hum.set_title('Humidity')
+                    ax_hum.set_xlabel('Time')
+                    ax_hum.set_ylabel('Humidity (%)')
+                    for i in range(16):
+                        ax_hum.plot(data['Timestamp'][-max_points:], data[f'Hum{i+1}'][-max_points:], label=f'Hum{i+1}')
+
+                    plt.pause(0.5)
+            except ValueError as e:
+                print(f"Could not convert data to float: {line}, error: {e}")
+except KeyboardInterrupt:
+    plt.ioff()
+finally:
+    # Save the data to a CSV file
+    df = pd.DataFrame(data)
+    csv_filename = 'arduino_data.csv'
+    df.to_csv(csv_filename, index=False)
+    print(f"Data saved to '{csv_filename}'")
+    ser.close()
+```
+
+<img src="./python_plot.png" alt="python_plot" style="width:66%;" />