串口输出COM3神秘消失
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UART Control
This example shows how to use the serial port on your OpenMV Cam. Attach pin
P4 to the serial input of a serial LCD screen to see "Hello World!" printed
on the serial LCD display.
import time
from pyb import UARTAlways pass UART 3 for the UART number for your OpenMV Cam.
The second argument is the UART baud rate. For a more advanced UART control
example see the BLE-Shield driver.
uart = UART(3, 19200)
import sensor, image, time, maththreshold_index = 0 # 0 for red, 1 for green, 2 for blue
Color Tracking Thresholds (L Min, L Max, A Min, A Max, B Min, B Max)
The below thresholds track in general red/green/blue things. You may wish to tune them...
thresholds = [(30, 100, 15, 127, 15, 127), # generic_red_thresholds
(30, 100, -64, -8, -32, 32), # generic_green_thresholds
(0, 30, 0, 64, -128, 0)] # generic_blue_thresholdssensor.reset()
sensor.set_pixformat(sensor.RGB565)
sensor.set_framesize(sensor.QVGA)
sensor.skip_frames(time = 2000)
sensor.set_auto_gain(False) # must be turned off for color tracking
sensor.set_auto_whitebal(False) # must be turned off for color tracking
clock = time.clock()Only blobs that with more pixels than "pixel_threshold" and more area than "area_threshold" are
returned by "find_blobs" below. Change "pixels_threshold" and "area_threshold" if you change the
camera resolution. "merge=True" merges all overlapping blobs in the image.
while(True):
clock.tick()
img = sensor.snapshot()
for blob in img.find_blobs([thresholds[threshold_index]], pixels_threshold=200, area_threshold=200, merge=True):
# These values depend on the blob not being circular - otherwise they will be shaky.
if blob.elongation() > 0.5:
img.draw_edges(blob.min_corners(), color=(255,0,0))
img.draw_line(blob.major_axis_line(), color=(0,255,0))
img.draw_line(blob.minor_axis_line(), color=(0,0,255))
# These values are stable all the time.
img.draw_rectangle(blob.rect())
img.draw_cross(blob.cx(), blob.cy())
# Note - the blob rotation is unique to 0-180 only.
img.draw_keypoints([(blob.cx(), blob.cy(), int(math.degrees(blob.rotation())))], size=20)
uart.write("1")
#print("none")原本是有COM3 和COM5,突然就剩下COM5了,代码把串口改为5,会报错ValueError:UART(5)doesn't exist
串口助手显示如图
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代码里的UART3只和OpenMV的引脚有关,与电脑上的COM几无关。你换一个电脑,或者用其他串口模块,会发现COM几是变化的。
解决办法,代码不要动,继续用UART 3, COM口的数字在设备管理器查看对应的。
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@kidswong999 谢谢你,我OK了