Openmv小结(电设、智能车)

距离上次做这些嵌入式的竞赛已经过去一年了，这里简单总结一下去年用的比较多的一个器件–openmv吧
以恩智浦版openmv为例(以后貌似都没有恩智浦赞助了)

电赛板球系统

'''
Design by ***
device:IMXRT1062_openmv
@brief:17年国赛板球系统代码
'''
import sensor, image, time
from pyb import UART
from struct import pack
# For color tracking to work really well you should ideally be in a very, very,
# very, controlled enviroment where the lighting is constant...

uart = UART(4, 115200)
sensor.reset() # Initialize the camera sensor.
sensor.set_pixformat(sensor.GRAYSCALE) # use 灰度
sensor.set_framesize(sensor.QQVGA) # sensor.QVGA: 320x240 QQVGA: 160x120
sensor.skip_frames(10) # Let new settings take affect.
#灰度图不需要关闭白平衡
clock = time.clock() # Tracks FPS.
red_threshold_01 = (105,122)
while(True):
    clock.tick() # Track elapsed milliseconds between snapshots().
    #img = sensor.snapshot()
    img = sensor.snapshot().lens_corr(strength = 1.8, zoom = 1.0) # Take a picture and return the image.
   #  pixels_threshold=100, area_threshold=100
    area=(8,1,142,119)
    #blobs = img.find_blobs([red_threshold_01])
    blobs = img.find_blobs([red_threshold_01],roi=area,area_threshold=8)
    if blobs:
    #如果找到了目标颜色
        print(blobs)
        for b in blobs:
        #迭代找到的目标颜色区域
            # Draw a rect around the blob.
            img.draw_rectangle(b[0:4]) # rect
            #用矩形标记出目标颜色区域
            #img.draw_cross(b[5], b[6]) # cx, cy
            ##在目标颜色区域的中心画十字形标记
            #data=bytearray([0xfe,0xfa,b[5],b[6],0xff])
            data=pack("<bbHHb",0xfe,0xfa,b[5],b[6],0xff)
            uart.write(data)

    print(clock.fps()) # Note: Your OpenMV Cam runs about half as fast while
    # connected to your computer. The FPS should increase once disconnected.

识别AprilTag

'''
Design by CWJ
device:IMXRT1062
找最近的AprilTag
'''
import sensor, image, time, math
import pyb
sensor.reset()
sensor.set_pixformat(sensor.GRAYSCALE)
sensor.set_framesize(sensor.QQVGA)
sensor.skip_frames(time = 2000)
sensor.set_auto_gain(False)
sensor.set_auto_whitebal(False)
sensor.set_auto_exposure(False, exposure_us=3000) # make smaller to go faster
clock = time.clock()
uart = pyb.UART(4, 115200)
uart.init(115200, bits=8, parity=None, stop=1)
while(True):
    img = sensor.snapshot()
    tag=img.find_apriltags(families=image.TAG25H9)
    if len(tag)>0:
        key=0
        max_x=0
        max_y=0
        for i in range(len(tag)):
            if tag[i].cy() > max_y:
                max_x=tag[i].cx()
                max_y=tag[i].cy()
                key=i
                if tag[i].cx() > max_x :
                    max_x=tag[i].cx()
                    max_y=tag[i].cy()
                    key=tag[i].id()
        tag=tag[key]
        img.draw_rectangle(tag.rect(), color = (255, 0, 0))
        img.draw_cross(tag.cx(), tag.cy(), color = (0, 255, 0))
        x=int(128+tag.x_translation()*10)
        y=int(128+tag.y_translation()*10)
        uart.writechar(0xfe)
        uart.writechar(0xfa)
        uart.writechar(tag.id())
        uart.writechar(x)
        uart.writechar(y)
        uart.writechar(int(180*tag.rotation()/math.pi*100)&0xff)
        uart.writechar((int(180*tag.rotation()/math.pi*100)>>8)&0xff)
        uart.writechar(0xff)
        print(180*tag.rotation()/math.pi)
        print(tag)

串口模块

'''
Design by ***
IMXRT1062_uart_module
'''
# UART Control 串口通信

import time
from pyb import UART

uart = UART(4, 115200)                         # 使用给定波特率初始化
uart.init(115200, bits=8, parity=None, stop=1) # 使用给定参数初始化

'''
发送数据：
一帧数据的每一个Byte必须要以字节的显示发送（data = bytearray([x,y])），
而不能是用16进制发送（uart.write("%x %x \r"%(x,y))），
他们两个函数在串口助手里面看到的内容是一样的（大小写的区别），
但是后者是无法让单片机接收到的。
如果采用后者发送方式，就会出现openmv和单片机分别于PC通讯没问题，但是二者之间却无法通讯的问题
https://blog.csdn.net/LJH_1999/article/details/88782943
'''
def sending_data():
    global uart
    '''
    data=bytearray([0xFF,0xFA,X_black_Sign,Y_black_Sign,0xFD,0XF6])
    0xFF, 0xFA...0xFD, 0xF6
    data=struct.pack("<bbHHb",0xfe,0xfa,b[5],b[6],0xff)
    '''
    uart.write("haha\n")
'''
接收数据：
openmv收数据时前加b'后加'
例：电脑发444r\n
收到b'444r\n'
'''
def recive_data():
    global uart

    if uart.any():
        tmp_data = uart.readline()
        uart.write("RECIVED : %s\n"%tmp_data)
        print(tmp_data)

while(True):
    sending_data()
    recive_data()
    time.sleep(1000)