• 機器人專題(使用樹莓派Pi 3)

PM2.5感測器

• 講義

• • PMS5003T感測器介紹

    PMS5003T感測器是一款可以用來測量空氣中的PM2.5、溫度等物理量，並且將它轉換為數字的感測器。

    https://www.icshop.com.tw/products/368030200769

  • 將感測器接上樹莓派的GPIO

    

    https://www.icshop.com.tw/products/368030200769

  • 讀取PM2.5的Python程式碼

    pip install pyserial

    #!/usr/bin/env python3
    """讀取 PMS5003 的 PM1.0 / PM2.5 / PM10（Raspberry Pi OS Trixie, pyserial）"""
    import struct
    import time
    import serial
    
    PORT = "/dev/serial0"   # Pi 5 若沒有 serial0，改用 /dev/ttyAMA0
    BAUD = 9600
    FRAME_LEN = 32
    
    
    def read_frame(ser):
        """同步到 0x42 0x4D header，回傳完整 32-byte frame（含 header）"""
        while True:
            b = ser.read(1)
            if b != b"\x42":
                continue
            if ser.read(1) != b"\x4d":
                continue
            rest = ser.read(FRAME_LEN - 2)
            if len(rest) != FRAME_LEN - 2:
                continue  # timeout，重來
            frame = b"\x42\x4d" + rest
            # 驗證 checksum：前 30 bytes 總和 == 最後 2 bytes
            if sum(frame[:30]) != struct.unpack(">H", frame[30:])[0]:
                continue
            return frame
    
    
    def parse(frame):
        # 長度 + 13 筆資料 + checksum = 15 個 uint16 (big-endian)
        v = struct.unpack(">15H", frame[2:])
        return {
            "pm1_cf1":  v[1],  "pm25_cf1": v[2],  "pm10_cf1": v[3],   # 標準顆粒 (CF=1)
            "pm1":      v[4],  "pm25":     v[5],  "pm10":     v[6],   # 大氣環境值 (一般用這組)
            "n0_3": v[7], "n0_5": v[8], "n1_0": v[9],                 # 每 0.1L 顆粒數
            "n2_5": v[10], "n5_0": v[11], "n10": v[12],
        }
    
    
    def main():
        with serial.Serial(PORT, BAUD, timeout=2) as ser:
            ser.reset_input_buffer()
            print("PMS5003 讀取中，Ctrl+C 結束")
            while True:
                d = parse(read_frame(ser))
                print(time.strftime("%H:%M:%S"),
                      f"PM1.0={d['pm1']:3d}  PM2.5={d['pm25']:3d}  PM10={d['pm10']:3d} µg/m³")
    
    
    if __name__ == "__main__":
        try:
            main()
        except KeyboardInterrupt:
            pass

     

    #!/usr/bin/env python3
    """讀取 PMS5003T 的 PM1.0 / PM2.5 / PM10 / 溫度 / 濕度（Raspberry Pi OS Trixie, pyserial）"""
    import struct
    import time
    import serial
    
    PORT = "/dev/serial0"   # Pi 5 若沒有 serial0，改用 /dev/ttyAMA0
    BAUD = 9600
    FRAME_LEN = 32
    
    
    def read_frame(ser):
        """同步到 0x42 0x4D header，回傳完整 32-byte frame（含 header）"""
        while True:
            b = ser.read(1)
            if b != b"\x42":
                continue
            if ser.read(1) != b"\x4d":
                continue
            rest = ser.read(FRAME_LEN - 2)
            if len(rest) != FRAME_LEN - 2:
                continue  # timeout，重來
            frame = b"\x42\x4d" + rest
            # 驗證 checksum：前 30 bytes 總和 == 最後 2 bytes
            if sum(frame[:30]) != struct.unpack(">H", frame[30:])[0]:
                continue
            return frame
    
    
    def parse(frame):
        # 長度 + 13 筆資料 + checksum = 15 個 uint16 (big-endian)
        v = struct.unpack(">15H", frame[2:])
        temp = struct.unpack(">h", frame[24:26])[0] / 10.0   # Data11，有號 int16，°C
        humi = v[12] / 10.0                                   # Data12，%RH
        return {
            "pm1_cf1":  v[1],  "pm25_cf1": v[2],  "pm10_cf1": v[3],   # 標準顆粒 (CF=1)
            "pm1":      v[4],  "pm25":     v[5],  "pm10":     v[6],   # 大氣環境值 (一般用這組)
            "n0_3": v[7], "n0_5": v[8], "n1_0": v[9], "n2_5": v[10],  # 每 0.1L 顆粒數
            "temp": temp, "humi": humi,
        }
    
    
    def main():
        with serial.Serial(PORT, BAUD, timeout=2) as ser:
            ser.reset_input_buffer()
            print("PMS5003T 讀取中，Ctrl+C 結束")
            while True:
                d = parse(read_frame(ser))
                print(time.strftime("%H:%M:%S"),
                      f"PM1.0={d['pm1']:3d}  PM2.5={d['pm25']:3d}  PM10={d['pm10']:3d} µg/m³  "
                      f"T={d['temp']:.1f}°C  RH={d['humi']:.1f}%")
    
    
    if __name__ == "__main__":
        try:
            main()
        except KeyboardInterrupt:
            pass