lora_plug/test_send.py

import serial_module
import cv2
import time
import threading

# 全局变量
frame = None
frame_lock = threading.Lock()
thread_started = False

# 摄像头读取线程
def cap_thread():
    global frame, thread_started
    cap = cv2.VideoCapture(0)
    if not cap.isOpened():
        print("Error: Could not open camera.")
        return
    
    # 标记线程已启动
    thread_started = True

    while True:
        time_now = time.time()
        ret, temp_frame = cap.read()
        if ret:
            with frame_lock:
                # 在图像上打印时间
                # print(f"Time: {time_now:.2f}")
                cv2.putText(temp_frame, f"{time_now:.2f}", (10, 50), cv2.FONT_HERSHEY_SIMPLEX, 2, (0, 0, 255), 4)
                frame = temp_frame
        else:
            print("Error: Failed to read frame from camera.")
            time.sleep(0.1)  # 短暂休眠，避免频繁尝试读取

# 初始化串口
serial_module.init("/dev/ttyUSB0")

# 启动摄像头读取线程
threading.Thread(target=cap_thread, daemon=True).start()

# 等待子线程初始化完成
while not thread_started:
    time.sleep(0.1)

# 主线程处理逻辑
# for _ in range(100):
while True:
    time_via = time.time()

    # 检查帧是否可用
    with frame_lock:
        if frame is None:
            # print('frame is None')
            time.sleep(0.1)  # 短暂休眠，避免频繁检测
            continue
        
        # 调整帧大小
        try:
            frame_resized = cv2.resize(frame, (224, 224))
        except Exception as e:
            print(f"Error resizing frame: {e}")
            continue

    # 编码帧为 JPEG 格式
    try:
        frame_jpg = cv2.imencode('.jpg', frame_resized, [int(cv2.IMWRITE_JPEG_QUALITY), 50])[1].tobytes()
    except Exception as e:
        print(f"Error encoding frame: {e}")
        continue

    # 打印帧大小并发送数据
    print(f"Frame size: {len(frame_jpg)} bytes")
    serial_module.send(frame_jpg)

    # 保存帧到文件（用于调试）
    try:
        cv2.imwrite('test_send.jpg', frame_resized)
    except Exception as e:
        print(f"Error saving frame: {e}")

    # 打印时间消耗
    print(f"Time taken: {time.time() - time_via:.3f} seconds")

    # 控制循环频率
    # time.sleep(4)

    # 按 'q' 键退出
    if cv2.waitKey(1) & 0xFF == ord('q'):
        break

# 释放资源
cv2.destroyAllWindows()