openmv 识别颜色（黄色，蓝色，绿色），形状（长方形，圆形，五角星，三角形）代码

下面是一个简单的OpenMV代码，用于识别颜色和形状：

import sensor, image, time
from pyb import UART

# 颜色阈值
yellow_threshold = (43, 100, -33, 18, 8, 62)
blue_threshold = (0, 100, -128, 80, -128, -10)
green_threshold = (10, 60, -50, -20, -30, 60)

# 形状阈值
rect_threshold = 0.2
circle_threshold = 0.8
star_threshold = 0.2
triangle_threshold = 0.2

# 初始化串口
uart = UART(3, baudrate=9600, timeout_char=1000)

# 初始化摄像头
sensor.reset()
sensor.set_pixformat(sensor.RGB565)
sensor.set_framesize(sensor.QVGA)
sensor.skip_frames(time = 2000)
sensor.set_auto_gain(False)
sensor.set_auto_whitebal(False)

# 主循环
while(True):
    img = sensor.snapshot()
    # 识别黄色
    blobs = img.find_blobs([yellow_threshold])
    for blob in blobs:
        # 形状检测：长方形
        if blob.w() / blob.h() > 1 - rect_threshold and blob.w() / blob.h() < 1 + rect_threshold:
            uart.write("Yellow rectangle\n")
        # 形状检测：圆形
        elif blob.circularity() > circle_threshold:
            uart.write("Yellow circle\n")
        # 形状检测：五角星
        elif blob.corners() == 5 and blob.area() > 500 and blob.area() < 5000:
            uart.write("Yellow star\n")
        # 形状检测：三角形
        elif blob.corners() == 3 and blob.area() > 500 and blob.area() < 5000:
            uart.write("Yellow triangle\n")
        
    # 识别蓝色
    blobs = img.find_blobs([blue_threshold])
    for blob in blobs:
        # 形状检测：长方形
        if blob.w() / blob.h() > 1 - rect_threshold and blob.w() / blob.h() < 1 + rect_threshold:
            uart.write("Blue rectangle\n")
        # 形状检测：圆形
        elif blob.circularity() > circle_threshold:
            uart.write("Blue circle\n")
        # 形状检测：五角星
        elif blob.corners() == 5 and blob.area() > 500 and blob.area() < 5000:
            uart.write("Blue star\n")
        # 形状检测：三角形
        elif blob.corners() == 3 and blob.area() > 500 and blob.area() < 5000:
            uart.write("Blue triangle\n")
        
    # 识别绿色
    blobs = img.find_blobs([green_threshold])
    for blob in blobs:
        # 形状检测：长方形
        if blob.w() / blob.h() > 1 - rect_threshold and blob.w() / blob.h() < 1 + rect_threshold:
            uart.write("Green rectangle\n")
        # 形状检测：圆形
        elif blob.circularity() > circle_threshold:
            uart.write("Green circle\n")
        # 形状检测：五角星
        elif blob.corners() == 5 and blob.area() > 500 and blob.area() < 5000:
            uart.write("Green star\n")
        # 形状检测：三角形
        elif blob.corners() == 3 and blob.area() > 500 and blob.area() < 5000:
            uart.write("Green triangle\n")

这个代码使用`find_blobs()`函数识别颜色，使用`circularity()`和`corners()`函数进行形状检测。其中，`rect_threshold`、`circle_threshold`、`star_threshold`和`triangle_threshold`分别表示长方形、圆形、五角星和三角形的形状阈值，可以根据实际情况进行调整。`uart.write()`函数用于将识别结果发送到串口。