追小球的云台代码。联机时，舵机能180度跟随。而脱机时，舵机只能转半圈。

[zx2b]

占空比的限制也调过了，联机的时候一直很正常，但是一旦脱机就只能转动半边，另一边没反应。一开始以为P调小了 但是调过P也没反应 ，代码如下。

import sensor, image, time

from pid import PID
from pyb import Servo
from pyb import UART
import json

pan_servo=Servo(1)
pan_servo.calibration(500,2500,500)


red_threshold  =  (21, 100, -82, -28, -73, 59)

#pan_pid = PID(p=0.07, i=0, imax=90) #脱机运行或者禁用图像传输，用这个
pan_pid = PID(p=1.5, i=0, imax=90)#在线调试使用这个PID


sensor.reset() # Initialize the camera sensor.
sensor.set_pixformat(sensor.RGB565) # use RGB565.
sensor.set_framesize(sensor.QVGA) # use QQVGA for speed.
sensor.skip_frames(10) # Let new settings take affect.
sensor.set_auto_whitebal(False) # turn this off.
clock = time.clock() # Tracks FPS.
uart = UART(3, 9600)

K=1911

def find_max(blobs):
    max_size=0
    for blob in blobs:
        if blob[2]*blob[3] > max_size:
            max_blob=blob
            max_size = blob[2]*blob[3]
    return max_blob


while(True):
    clock.tick() # Track elapsed milliseconds between snapshots().
    img = sensor.snapshot() # Take a picture and return the image.

    blobs = img.find_blobs([red_threshold])
    if blobs:
        max_blob = find_max(blobs)
        pan_error = max_blob.cx()-img.width()/2

#        output_str=bytearray([max_blob.cx(),max_blob.cy()])
#        output_str="%d" % (pan_servo.angle())
 #       uart.write(output_str+'\r\n')
#        print("pan_error: ", pan_error)

        img.draw_rectangle(max_blob.rect()) # rect
        img.draw_cross(max_blob.cx(), max_blob.cy()) # cx, cy
        Lm = (max_blob.w()+max_blob.h())/2
        length = K/Lm
       #output_str="%d" % (length)
         #uart.write(output_str)
       # uart.write(output_str+'\r\n')
       # print(length)
        uart.writechar(int(length))
        pan_output=pan_pid.get_pid(pan_error,1)/2
#        print("pan_output",pan_output)
        pan_servo.angle(pan_servo.angle()+pan_output)

[kidswong999]

电脑调试的时候，右上角，禁用framebuffer，就是和脱机一样的。看一下效果。