Tag Archives: Servos

<span data-mce-type="bookmark" style="display: inline-block; width: 0px; overflow: hidden; line-height: 0;" class="mce_SELRES_start"></span>
In this lesson we learn how to use OpenCV on the Jetson Xavier NX to track an object of interest in with two cameras on two Pan/Tilt servo brackets. The system tracks based on HSV color space, but the same basic setup could be used with other object detection algorithms. In this project we are using the Jetson Xavier NX, which you can pick up HERE. You will also need to of the bracket/servo kits, which you can get HERE, and then two Raspberry Pi Version two cameras, available HERE.

import cv2
import numpy as np
import time
from adafruit_servokit import ServoKit
print(cv2.__version__)
timeMark=time.time()
dtFIL=0

def nothing(x):
    pass

cv2.namedWindow('TrackBars')
cv2.moveWindow('TrackBars',1320,0)
cv2.createTrackbar('hueLower', 'TrackBars',100,179,nothing)
cv2.createTrackbar('hueUpper', 'TrackBars',116,179,nothing)
cv2.createTrackbar('satLow', 'TrackBars',160,255,nothing)
cv2.createTrackbar('satHigh', 'TrackBars',255,255,nothing)
cv2.createTrackbar('valLow', 'TrackBars',150,255,nothing)
cv2.createTrackbar('valHigh', 'TrackBars',255,255,nothing)
kit=ServoKit(channels=16)

tilt1=90
pan1=90
tilt2=90
pan2=90

kit.servo[0].angle=pan1
kit.servo[1].angle=tilt1
kit.servo[2].angle=pan2
kit.servo[3].angle=tilt2

width=720
height=480
flip=2
font=cv2.FONT_HERSHEY_SIMPLEX
camSet1='nvarguscamerasrc sensor-id=0 ee-mode=1 ee-strength=0 tnr-mode=2 tnr-strength=1 wbmode=3 ! video/x-raw(memory:NVMM), width=3264, height=2464, framerate=21/1,format=NV12 ! nvvidconv flip-method='+str(flip)+' ! video/x-raw, width='+str(width)+', height='+str(height)+', format=BGRx ! videoconvert ! video/x-raw, format=BGR ! videobalance contrast=1.3 brightness=-.2 saturation=1.2 ! appsink drop=True'
camSet2='nvarguscamerasrc sensor-id=1 ee-mode=1 ee-strength=0 tnr-mode=2 tnr-strength=1 wbmode=3 ! video/x-raw(memory:NVMM), width=3264, height=2464, framerate=21/1,format=NV12 ! nvvidconv flip-method='+str(flip)+' ! video/x-raw, width='+str(width)+', height='+str(height)+', format=BGRx ! videoconvert ! video/x-raw, format=BGR ! videobalance contrast=1.3 brightness=-.2 saturation=1.2 ! appsink drop=True'

#camSet='nvarguscamerasrc sensor-id=0 ! video/x-raw(memory:NVMM), width=3264, height=2464, framerate=21/1,format=NV12 ! nvvidconv flip-method='+str(flip)+' ! video/x-raw, width='+str(width)+', height='+str(height)+', format=BGRx ! videoconvert ! video/x-raw, format=BGR ! appsink'
#camSet ='v4l2src device=/dev/video1 ! video/x-raw,width='+str(width)+',height='+str(height)+',framerate=20/1 ! videoconvert ! appsink'
cam1=cv2.VideoCapture(camSet1)
cam2=cv2.VideoCapture(camSet2)
while True:
    _, frame1 = cam1.read()
    _, frame2 = cam2.read()

    hsv1=cv2.cvtColor(frame1,cv2.COLOR_BGR2HSV)
    hsv2=cv2.cvtColor(frame2,cv2.COLOR_BGR2HSV)

    hueLow=cv2.getTrackbarPos('hueLower', 'TrackBars')
    hueUp=cv2.getTrackbarPos('hueUpper', 'TrackBars')

    Ls=cv2.getTrackbarPos('satLow', 'TrackBars')
    Us=cv2.getTrackbarPos('satHigh', 'TrackBars')

    Lv=cv2.getTrackbarPos('valLow', 'TrackBars')
    Uv=cv2.getTrackbarPos('valHigh', 'TrackBars')

    l_b=np.array([hueLow,Ls,Lv])
    u_b=np.array([hueUp,Us,Uv])

    FGmask1=cv2.inRange(hsv1,l_b,u_b)
    FGmask2=cv2.inRange(hsv2,l_b,u_b)

    cv2.imshow('FGmask1',FGmask1)
    cv2.moveWindow('FGmask1',0,0)

    contours1,_ = cv2.findContours(FGmask1,cv2.RETR_EXTERNAL,cv2.CHAIN_APPROX_SIMPLE)
    contours1=sorted(contours1,key=lambda x:cv2.contourArea(x),reverse=True)
    for cnt in contours1:
        area=cv2.contourArea(cnt)
        (x,y,w,h)=cv2.boundingRect(cnt)
        if area>=100:
            cv2.rectangle(frame1,(x,y),(x+w,y+h),(0,255,255),3)
            objX=x+w/2
            objY=y+h/2
            errorPan1=objX-width/2
            errorTilt1=objY-height/2
            if abs(errorPan1)>15:
                pan1=pan1+errorPan1/40
            if abs(errorTilt1)>15:
                tilt1=tilt1-errorTilt1/40
            if pan1>180:
                pan1=180
                print('Pan Out of Range')
            if pan1<0:
                pan1=0
                print('Pan Out of Range')
            if tilt1>180:
                tilt1=180
                print('Tilt Out of Range')
            if tilt1<0:
                tilt1=0
            kit.servo[2].angle=pan1
            kit.servo[3].angle=tilt1
            break
    
    contours2,_ = cv2.findContours(FGmask2,cv2.RETR_EXTERNAL,cv2.CHAIN_APPROX_SIMPLE)
    contours2=sorted(contours2,key=lambda x:cv2.contourArea(x),reverse=True)
    for cnt in contours2:
        area=cv2.contourArea(cnt)
        (x,y,w,h)=cv2.boundingRect(cnt)
        if area>=100:
            cv2.rectangle(frame2,(x,y),(x+w,y+h),(0,255,255),3)
            objX=x+w/2
            objY=y+h/2
            errorPan2=objX-width/2
            errorTilt2=objY-height/2
            if abs(errorPan2)>15:
                pan2=pan2+errorPan2/40
            if abs(errorTilt2)>15:
                tilt2=tilt2-errorTilt2/40
            if pan2>180:
                pan2=180
                print('Pan Out of Range')
            if pan2<0:
                pan2=0
                print('Pan Out of Range')
            if tilt2>180:
                tilt2=180
                print('Tilt Out of Range')
            if tilt2<0:
                tilt2=0
            kit.servo[0].angle=pan2
            kit.servo[1].angle=tilt2            
            break

    frame3=np.hstack((frame1,frame2))
    dt=time.time()-timeMark
    timeMark=time.time()
    dtFIL=.9*dtFIL + .1*dt
    fps=1/dtFIL
    cv2.rectangle(frame3,(0,0),(150,40),(0,0,255),-1)
    cv2.putText(frame3,'fps: '+str(round(fps,1)),(0,30),font,1,(0,255,255),2)

    #cv2.imshow('myCam1',frame1)
    #cv2.imshow('myCam2',frame2)
    cv2.imshow('comboCam',frame3)
    cv2.moveWindow('comboCam',0,450)

    if cv2.waitKey(1)==ord('q'):
        break
cam1.release()
cam2.release()
cv2.destroyAllWindows()

100

101

102

103

104

105

106

107

108

109

110

111

112

113

114

115

116

117

118

119

120

121

122

123

124

125

126

127

128

129

130

131

132

133

134

135

136

137

138

139

140

141

142

143

144

145

import cv2

import numpy as np

import time

from adafruit_servokit import ServoKit

print(cv2.__version__)

timeMark=time.time()

dtFIL=0

def nothing(x):

pass

cv2.namedWindow('TrackBars')

cv2.moveWindow('TrackBars',1320,0)

cv2.createTrackbar('hueLower', 'TrackBars',100,179,nothing)

cv2.createTrackbar('hueUpper', 'TrackBars',116,179,nothing)

cv2.createTrackbar('satLow', 'TrackBars',160,255,nothing)

cv2.createTrackbar('satHigh', 'TrackBars',255,255,nothing)

cv2.createTrackbar('valLow', 'TrackBars',150,255,nothing)

cv2.createTrackbar('valHigh', 'TrackBars',255,255,nothing)

kit=ServoKit(channels=16)

tilt1=90

pan1=90

tilt2=90

pan2=90

kit.servo[0].angle=pan1

kit.servo[1].angle=tilt1

kit.servo[2].angle=pan2

kit.servo[3].angle=tilt2

width=720

height=480

flip=2

font=cv2.FONT_HERSHEY_SIMPLEX

camSet1='nvarguscamerasrc sensor-id=0 ee-mode=1 ee-strength=0 tnr-mode=2 tnr-strength=1 wbmode=3 ! video/x-raw(memory:NVMM), width=3264, height=2464, framerate=21/1,format=NV12 ! nvvidconv flip-method='+str(flip)+' ! video/x-raw, width='+str(width)+', height='+str(height)+', format=BGRx ! videoconvert ! video/x-raw, format=BGR ! videobalance contrast=1.3 brightness=-.2 saturation=1.2 ! appsink drop=True'

camSet2='nvarguscamerasrc sensor-id=1 ee-mode=1 ee-strength=0 tnr-mode=2 tnr-strength=1 wbmode=3 ! video/x-raw(memory:NVMM), width=3264, height=2464, framerate=21/1,format=NV12 ! nvvidconv flip-method='+str(flip)+' ! video/x-raw, width='+str(width)+', height='+str(height)+', format=BGRx ! videoconvert ! video/x-raw, format=BGR ! videobalance contrast=1.3 brightness=-.2 saturation=1.2 ! appsink drop=True'

#camSet='nvarguscamerasrc sensor-id=0 ! video/x-raw(memory:NVMM), width=3264, height=2464, framerate=21/1,format=NV12 ! nvvidconv flip-method='+str(flip)+' ! video/x-raw, width='+str(width)+', height='+str(height)+', format=BGRx ! videoconvert ! video/x-raw, format=BGR ! appsink'

#camSet ='v4l2src device=/dev/video1 ! video/x-raw,width='+str(width)+',height='+str(height)+',framerate=20/1 ! videoconvert ! appsink'

cam1=cv2.VideoCapture(camSet1)

cam2=cv2.VideoCapture(camSet2)

while True:

_, frame1 = cam1.read()

_, frame2 = cam2.read()

hsv1=cv2.cvtColor(frame1,cv2.COLOR_BGR2HSV)

hsv2=cv2.cvtColor(frame2,cv2.COLOR_BGR2HSV)

hueLow=cv2.getTrackbarPos('hueLower', 'TrackBars')

hueUp=cv2.getTrackbarPos('hueUpper', 'TrackBars')

Ls=cv2.getTrackbarPos('satLow', 'TrackBars')

Us=cv2.getTrackbarPos('satHigh', 'TrackBars')

Lv=cv2.getTrackbarPos('valLow', 'TrackBars')

Uv=cv2.getTrackbarPos('valHigh', 'TrackBars')

l_b=np.array([hueLow,Ls,Lv])

u_b=np.array([hueUp,Us,Uv])

FGmask1=cv2.inRange(hsv1,l_b,u_b)

FGmask2=cv2.inRange(hsv2,l_b,u_b)

cv2.imshow('FGmask1',FGmask1)

cv2.moveWindow('FGmask1',0,0)

contours1,_ = cv2.findContours(FGmask1,cv2.RETR_EXTERNAL,cv2.CHAIN_APPROX_SIMPLE)

contours1=sorted(contours1,key=lambda x:cv2.contourArea(x),reverse=True)

for cnt in contours1:

area=cv2.contourArea(cnt)

(x,y,w,h)=cv2.boundingRect(cnt)

if area>=100:

cv2.rectangle(frame1,(x,y),(x+w,y+h),(0,255,255),3)

objX=x+w/2

objY=y+h/2

errorPan1=objX-width/2

errorTilt1=objY-height/2

if abs(errorPan1)>15:

pan1=pan1+errorPan1/40

if abs(errorTilt1)>15:

tilt1=tilt1-errorTilt1/40

if pan1>180:

pan1=180

print('Pan Out of Range')

if pan1<0:

pan1=0

print('Pan Out of Range')

if tilt1>180:

tilt1=180

print('Tilt Out of Range')

if tilt1<0:

tilt1=0

kit.servo[2].angle=pan1

kit.servo[3].angle=tilt1

break

contours2,_ = cv2.findContours(FGmask2,cv2.RETR_EXTERNAL,cv2.CHAIN_APPROX_SIMPLE)

contours2=sorted(contours2,key=lambda x:cv2.contourArea(x),reverse=True)

for cnt in contours2:

area=cv2.contourArea(cnt)

(x,y,w,h)=cv2.boundingRect(cnt)

if area>=100:

cv2.rectangle(frame2,(x,y),(x+w,y+h),(0,255,255),3)

objX=x+w/2

objY=y+h/2

errorPan2=objX-width/2

errorTilt2=objY-height/2

if abs(errorPan2)>15:

pan2=pan2+errorPan2/40

if abs(errorTilt2)>15:

tilt2=tilt2-errorTilt2/40

if pan2>180:

pan2=180

print('Pan Out of Range')

if pan2<0:

pan2=0

print('Pan Out of Range')

if tilt2>180:

tilt2=180

print('Tilt Out of Range')

if tilt2<0:

tilt2=0

kit.servo[0].angle=pan2

kit.servo[1].angle=tilt2

break

frame3=np.hstack((frame1,frame2))

dt=time.time()-timeMark

timeMark=time.time()

dtFIL=.9*dtFIL + .1*dt

fps=1/dtFIL

cv2.rectangle(frame3,(0,0),(150,40),(0,0,255),-1)

cv2.putText(frame3,'fps: '+str(round(fps,1)),(0,30),font,1,(0,255,255),2)

#cv2.imshow('myCam1',frame1)

#cv2.imshow('myCam2',frame2)

cv2.imshow('comboCam',frame3)

cv2.moveWindow('comboCam',0,450)

if cv2.waitKey(1)==ord('q'):

break

cam1.release()

cam2.release()

cv2.destroyAllWindows()

Jetson Xavier NX

Jetson Xavier NX Lesson 9: Tracking Objects with Two Cameras in OpenCV

July 15, 2020 admin

In this lesson we use OpenCV to track an object of interest based on HSV color value. We are running two cameras in parallel, and track the same object in both cameras. The code below is provided for your convenience, and is the code developed in the video lesson. If you want to play along at home, you can get your NVIDIA Jetson Xavier NX HERE.

In this lesson, we are running two raspberry pi cameras. I like the following ones and have verified that they work on the Xavier NX. You can pick your cameras up HERE.

import cv2
import numpy as np
import time
#from adafruit_servokit import ServoKit
print(cv2.__version__)
timeMark=time.time()
dtFIL=0

def nothing(x):
    pass

cv2.namedWindow('TrackBars')
cv2.moveWindow('TrackBars',1320,0)
cv2.createTrackbar('hueLower', 'TrackBars',100,179,nothing)
cv2.createTrackbar('hueUpper', 'TrackBars',116,179,nothing)
cv2.createTrackbar('satLow', 'TrackBars',160,255,nothing)
cv2.createTrackbar('satHigh', 'TrackBars',255,255,nothing)
cv2.createTrackbar('valLow', 'TrackBars',150,255,nothing)
cv2.createTrackbar('valHigh', 'TrackBars',255,255,nothing)
#kit=ServoKit(channels=16)

# tilt=90
# pan=90
# dTilt=10
# dPan=1

# kit.servo[0].angle=pan
# kit.servo[1].angle=tilt
# kit.servo[2].angle=pan
# kit.servo[3].angle=tilt

width=720
height=480
flip=2
font=cv2.FONT_HERSHEY_SIMPLEX
camSet1='nvarguscamerasrc sensor-id=0 ee-mode=1 ee-strength=0 tnr-mode=2 tnr-strength=1 wbmode=3 ! video/x-raw(memory:NVMM), width=3264, height=2464, framerate=21/1,format=NV12 ! nvvidconv flip-method='+str(flip)+' ! video/x-raw, width='+str(width)+', height='+str(height)+', format=BGRx ! videoconvert ! video/x-raw, format=BGR ! videobalance contrast=1.3 brightness=-.2 saturation=1.2 ! appsink drop=True'
camSet2='nvarguscamerasrc sensor-id=1 ee-mode=1 ee-strength=0 tnr-mode=2 tnr-strength=1 wbmode=3 ! video/x-raw(memory:NVMM), width=3264, height=2464, framerate=21/1,format=NV12 ! nvvidconv flip-method='+str(flip)+' ! video/x-raw, width='+str(width)+', height='+str(height)+', format=BGRx ! videoconvert ! video/x-raw, format=BGR ! videobalance contrast=1.3 brightness=-.2 saturation=1.2 ! appsink drop=True'

#camSet='nvarguscamerasrc sensor-id=0 ! video/x-raw(memory:NVMM), width=3264, height=2464, framerate=21/1,format=NV12 ! nvvidconv flip-method='+str(flip)+' ! video/x-raw, width='+str(width)+', height='+str(height)+', format=BGRx ! videoconvert ! video/x-raw, format=BGR ! appsink'
#camSet ='v4l2src device=/dev/video1 ! video/x-raw,width='+str(width)+',height='+str(height)+',framerate=20/1 ! videoconvert ! appsink'
cam1=cv2.VideoCapture(camSet1)
cam2=cv2.VideoCapture(camSet2)
while True:
    _, frame1 = cam1.read()
    _, frame2 = cam2.read()

    hsv1=cv2.cvtColor(frame1,cv2.COLOR_BGR2HSV)
    hsv2=cv2.cvtColor(frame2,cv2.COLOR_BGR2HSV)

    hueLow=cv2.getTrackbarPos('hueLower', 'TrackBars')
    hueUp=cv2.getTrackbarPos('hueUpper', 'TrackBars')

    Ls=cv2.getTrackbarPos('satLow', 'TrackBars')
    Us=cv2.getTrackbarPos('satHigh', 'TrackBars')

    Lv=cv2.getTrackbarPos('valLow', 'TrackBars')
    Uv=cv2.getTrackbarPos('valHigh', 'TrackBars')

    l_b=np.array([hueLow,Ls,Lv])
    u_b=np.array([hueUp,Us,Uv])

    FGmask1=cv2.inRange(hsv1,l_b,u_b)
    FGmask2=cv2.inRange(hsv2,l_b,u_b)

    cv2.imshow('FGmask1',FGmask1)
    cv2.moveWindow('FGmask1',0,0)

    contours1,_ = cv2.findContours(FGmask1,cv2.RETR_EXTERNAL,cv2.CHAIN_APPROX_SIMPLE)
    contours1=sorted(contours1,key=lambda x:cv2.contourArea(x),reverse=True)
    for cnt in contours1:
        area=cv2.contourArea(cnt)
        (x,y,w,h)=cv2.boundingRect(cnt)
        if area>=100:
            cv2.rectangle(frame1,(x,y),(x+w,y+h),(0,255,255),3)
            break
    
    contours2,_ = cv2.findContours(FGmask2,cv2.RETR_EXTERNAL,cv2.CHAIN_APPROX_SIMPLE)
    contours2=sorted(contours2,key=lambda x:cv2.contourArea(x),reverse=True)
    for cnt in contours2:
        area=cv2.contourArea(cnt)
        (x,y,w,h)=cv2.boundingRect(cnt)
        if area>=100:
            cv2.rectangle(frame2,(x,y),(x+w,y+h),(0,255,255),3)
            break

    frame3=np.hstack((frame1,frame2))
    dt=time.time()-timeMark
    timeMark=time.time()
    dtFIL=.9*dtFIL + .1*dt
    fps=1/dtFIL
    cv2.rectangle(frame3,(0,0),(150,40),(0,0,255),-1)
    cv2.putText(frame3,'fps: '+str(round(fps,1)),(0,30),font,1,(0,255,255),2)

    #cv2.imshow('myCam1',frame1)
    #cv2.imshow('myCam2',frame2)
    cv2.imshow('comboCam',frame3)
    cv2.moveWindow('comboCam',0,450)
    # kit.servo[0].angle=pan
    # kit.servo[2].angle=pan
    # pan=pan+dPan
    # if pan>=179 or pan<=1:
    #     dPan=dPan*(-1)
    #     tilt=tilt+dTilt
    #     kit.servo[1].angle=tilt
    #     kit.servo[3].angle=tilt
    #     if tilt>=169 or tilt<=11:
    #         dTilt=dTilt*(-1)
    if cv2.waitKey(1)==ord('q'):
        break
cam1.release()
cam2.release()
cv2.destroyAllWindows()

100

101

102

103

104

105

106

107

108

109

110

111

112

import cv2

import numpy as np

import time

#from adafruit_servokit import ServoKit

print(cv2.__version__)

timeMark=time.time()

dtFIL=0

def nothing(x):

pass

cv2.namedWindow('TrackBars')

cv2.moveWindow('TrackBars',1320,0)

cv2.createTrackbar('hueLower', 'TrackBars',100,179,nothing)

cv2.createTrackbar('hueUpper', 'TrackBars',116,179,nothing)

cv2.createTrackbar('satLow', 'TrackBars',160,255,nothing)

cv2.createTrackbar('satHigh', 'TrackBars',255,255,nothing)

cv2.createTrackbar('valLow', 'TrackBars',150,255,nothing)

cv2.createTrackbar('valHigh', 'TrackBars',255,255,nothing)

#kit=ServoKit(channels=16)

# tilt=90

# pan=90

# dTilt=10

# dPan=1

# kit.servo[0].angle=pan

# kit.servo[1].angle=tilt

# kit.servo[2].angle=pan

# kit.servo[3].angle=tilt

width=720

height=480

flip=2

font=cv2.FONT_HERSHEY_SIMPLEX

#camSet ='v4l2src device=/dev/video1 ! video/x-raw,width='+str(width)+',height='+str(height)+',framerate=20/1 ! videoconvert ! appsink'

cam1=cv2.VideoCapture(camSet1)

cam2=cv2.VideoCapture(camSet2)

while True:

_, frame1 = cam1.read()

_, frame2 = cam2.read()

hsv1=cv2.cvtColor(frame1,cv2.COLOR_BGR2HSV)

hsv2=cv2.cvtColor(frame2,cv2.COLOR_BGR2HSV)

hueLow=cv2.getTrackbarPos('hueLower', 'TrackBars')

hueUp=cv2.getTrackbarPos('hueUpper', 'TrackBars')

Ls=cv2.getTrackbarPos('satLow', 'TrackBars')

Us=cv2.getTrackbarPos('satHigh', 'TrackBars')

Lv=cv2.getTrackbarPos('valLow', 'TrackBars')

Uv=cv2.getTrackbarPos('valHigh', 'TrackBars')

l_b=np.array([hueLow,Ls,Lv])

u_b=np.array([hueUp,Us,Uv])

FGmask1=cv2.inRange(hsv1,l_b,u_b)

FGmask2=cv2.inRange(hsv2,l_b,u_b)

cv2.imshow('FGmask1',FGmask1)

cv2.moveWindow('FGmask1',0,0)

contours1,_ = cv2.findContours(FGmask1,cv2.RETR_EXTERNAL,cv2.CHAIN_APPROX_SIMPLE)

contours1=sorted(contours1,key=lambda x:cv2.contourArea(x),reverse=True)

for cnt in contours1:

area=cv2.contourArea(cnt)

(x,y,w,h)=cv2.boundingRect(cnt)

if area>=100:

cv2.rectangle(frame1,(x,y),(x+w,y+h),(0,255,255),3)

break

contours2,_ = cv2.findContours(FGmask2,cv2.RETR_EXTERNAL,cv2.CHAIN_APPROX_SIMPLE)

contours2=sorted(contours2,key=lambda x:cv2.contourArea(x),reverse=True)

for cnt in contours2:

area=cv2.contourArea(cnt)

(x,y,w,h)=cv2.boundingRect(cnt)

if area>=100:

cv2.rectangle(frame2,(x,y),(x+w,y+h),(0,255,255),3)

break

frame3=np.hstack((frame1,frame2))

dt=time.time()-timeMark

timeMark=time.time()

dtFIL=.9*dtFIL + .1*dt

fps=1/dtFIL

cv2.rectangle(frame3,(0,0),(150,40),(0,0,255),-1)

cv2.putText(frame3,'fps: '+str(round(fps,1)),(0,30),font,1,(0,255,255),2)

#cv2.imshow('myCam1',frame1)

#cv2.imshow('myCam2',frame2)

cv2.imshow('comboCam',frame3)

cv2.moveWindow('comboCam',0,450)

# kit.servo[0].angle=pan

# kit.servo[2].angle=pan

# pan=pan+dPan

# if pan>=179 or pan<=1:

# dPan=dPan*(-1)

# tilt=tilt+dTilt

# kit.servo[1].angle=tilt

# kit.servo[3].angle=tilt

# if tilt>=169 or tilt<=11:

# dTilt=dTilt*(-1)

if cv2.waitKey(1)==ord('q'):

break

cam1.release()

cam2.release()

cv2.destroyAllWindows()

Jetson Nano

AI on the Jetson Nano LESSON 32: Tracking an Object with Servos in OpenCV

March 28, 2020 admin

In this lesson we actively track an object using the Jetson Nano, pan/tilt servos, and OpenCV. In order for this code to work, you need to first set up your servos, as explained in Lesson 31 on youtube. Make sure to follow the instructions on that lesson before trying to do this one, as that will show you how to get your servos connected and set up.

import cv2
print(cv2.__version__)
import numpy as np
from adafruit_servokit import ServoKit
kit=ServoKit(channels=16)

pan=90
tilt=45
kit.servo[0].angle=pan
kit.servo[1].angle=tilt

def nothing(x):
    pass

cv2.namedWindow('Trackbars')
cv2.moveWindow('Trackbars',1320,0)

cv2.createTrackbar('hueLower', 'Trackbars',96,179,nothing)
cv2.createTrackbar('hueUpper', 'Trackbars',120,179,nothing)

cv2.createTrackbar('hue2Lower', 'Trackbars',50,179,nothing)
cv2.createTrackbar('hue2Upper', 'Trackbars',0,179,nothing)

cv2.createTrackbar('satLow', 'Trackbars',157,255,nothing)
cv2.createTrackbar('satHigh', 'Trackbars',255,255,nothing)
cv2.createTrackbar('valLow','Trackbars',100,255,nothing)
cv2.createTrackbar('valHigh','Trackbars',255,255,nothing)


dispW=640
dispH=480
flip=2
#Uncomment These next Two Line for Pi Camera
#camSet='nvarguscamerasrc !  video/x-raw(memory:NVMM), width=3264, height=2464, format=NV12, framerate=21/1 ! nvvidconv flip-method='+str(flip)+' ! video/x-raw, width='+str(dispW)+', height='+str(dispH)+', format=BGRx ! videoconvert ! video/x-raw, format=BGR ! appsink'
#cam= cv2.VideoCapture(camSet)

#Or, if you have a WEB cam, uncomment the next line
#(If it does not work, try setting to '1' instead of '0')
cam=cv2.VideoCapture(1)
width=cam.get(cv2.CAP_PROP_FRAME_WIDTH)
height=cam.get(cv2.CAP_PROP_FRAME_HEIGHT)
print('width:',width,'height:',height)
while True:   ret, frame = cam.read()
    #frame=cv2.imread('smarties.png')

    hsv=cv2.cvtColor(frame,cv2.COLOR_BGR2HSV)

    hueLow=cv2.getTrackbarPos('hueLower', 'Trackbars')
    hueUp=cv2.getTrackbarPos('hueUpper', 'Trackbars')

    hue2Low=cv2.getTrackbarPos('hue2Lower', 'Trackbars')
    hue2Up=cv2.getTrackbarPos('hue2Upper', 'Trackbars')

    Ls=cv2.getTrackbarPos('satLow', 'Trackbars')
    Us=cv2.getTrackbarPos('satHigh', 'Trackbars')

    Lv=cv2.getTrackbarPos('valLow', 'Trackbars')
    Uv=cv2.getTrackbarPos('valHigh', 'Trackbars')

    l_b=np.array([hueLow,Ls,Lv])
    u_b=np.array([hueUp,Us,Uv])

    l_b2=np.array([hue2Low,Ls,Lv])
    u_b2=np.array([hue2Up,Us,Uv])

    FGmask=cv2.inRange(hsv,l_b,u_b)
    FGmask2=cv2.inRange(hsv,l_b2,u_b2)
    FGmaskComp=cv2.add(FGmask,FGmask2)
    cv2.imshow('FGmaskComp',FGmaskComp)
    cv2.moveWindow('FGmaskComp',0,530)

    _,contours,_=cv2.findContours(FGmaskComp,cv2.RETR_EXTERNAL,cv2.CHAIN_APPROX_SIMPLE)
    contours=sorted(contours,key=lambda x:cv2.contourArea(x),reverse=True)
    for cnt in contours:
        area=cv2.contourArea(cnt)
        (x,y,w,h)=cv2.boundingRect(cnt)
        if area>=50:
            #cv2.drawContours(frame,[cnt],0,(255,0,0),3)
            cv2.rectangle(frame,(x,y),(x+w,y+h),(255,0,0),3)
            objX=x+w/2
            objY=y+h/2
            errorPan=objX-width/2
            errorTilt=objY-height/2
            if abs(errorPan)>15:
                pan=pan-errorPan/75
            if abs(errorTilt)>15:
                tilt=tilt-errorTilt/75


            if pan>180:
                pan=180
                print("Pan Out of  Range")   
            if pan<0:
                pan=0
                print("Pan Out of  Range") 
            if tilt>180:
                tilt=180
                print("Tilt Out of  Range") 
            if tilt<0:
                tilt=0
                print("Tilt Out of  Range")                 

            kit.servo[0].angle=pan
            kit.servo[1].angle=tilt 
            break        

    cv2.imshow('nanoCam',frame)
    cv2.moveWindow('nanoCam',0,0)
    

    if cv2.waitKey(1)==ord('q'):
        break
cam.release()
cv2.destroyAllWindows()

100

101

102

103

104

105

106

107

108

109

110

111

112

113

114

import cv2

print(cv2.__version__)

import numpy as np

from adafruit_servokit import ServoKit

kit=ServoKit(channels=16)

pan=90

tilt=45

kit.servo[0].angle=pan

kit.servo[1].angle=tilt

def nothing(x):

pass

cv2.namedWindow('Trackbars')

cv2.moveWindow('Trackbars',1320,0)

cv2.createTrackbar('hueLower', 'Trackbars',96,179,nothing)

cv2.createTrackbar('hueUpper', 'Trackbars',120,179,nothing)

cv2.createTrackbar('hue2Lower', 'Trackbars',50,179,nothing)

cv2.createTrackbar('hue2Upper', 'Trackbars',0,179,nothing)

cv2.createTrackbar('satLow', 'Trackbars',157,255,nothing)

cv2.createTrackbar('satHigh', 'Trackbars',255,255,nothing)

cv2.createTrackbar('valLow','Trackbars',100,255,nothing)

cv2.createTrackbar('valHigh','Trackbars',255,255,nothing)

dispW=640

dispH=480

flip=2

#Uncomment These next Two Line for Pi Camera

#camSet='nvarguscamerasrc ! video/x-raw(memory:NVMM), width=3264, height=2464, format=NV12, framerate=21/1 ! nvvidconv flip-method='+str(flip)+' ! video/x-raw, width='+str(dispW)+', height='+str(dispH)+', format=BGRx ! videoconvert ! video/x-raw, format=BGR ! appsink'

#cam= cv2.VideoCapture(camSet)

#Or, if you have a WEB cam, uncomment the next line

#(If it does not work, try setting to '1' instead of '0')

cam=cv2.VideoCapture(1)

width=cam.get(cv2.CAP_PROP_FRAME_WIDTH)

height=cam.get(cv2.CAP_PROP_FRAME_HEIGHT)

print('width:',width,'height:',height)

while True: ret, frame = cam.read()

#frame=cv2.imread('smarties.png')

hsv=cv2.cvtColor(frame,cv2.COLOR_BGR2HSV)

hueLow=cv2.getTrackbarPos('hueLower', 'Trackbars')

hueUp=cv2.getTrackbarPos('hueUpper', 'Trackbars')

hue2Low=cv2.getTrackbarPos('hue2Lower', 'Trackbars')

hue2Up=cv2.getTrackbarPos('hue2Upper', 'Trackbars')

Ls=cv2.getTrackbarPos('satLow', 'Trackbars')

Us=cv2.getTrackbarPos('satHigh', 'Trackbars')

Lv=cv2.getTrackbarPos('valLow', 'Trackbars')

Uv=cv2.getTrackbarPos('valHigh', 'Trackbars')

l_b=np.array([hueLow,Ls,Lv])

u_b=np.array([hueUp,Us,Uv])

l_b2=np.array([hue2Low,Ls,Lv])

u_b2=np.array([hue2Up,Us,Uv])

FGmask=cv2.inRange(hsv,l_b,u_b)

FGmask2=cv2.inRange(hsv,l_b2,u_b2)

FGmaskComp=cv2.add(FGmask,FGmask2)

cv2.imshow('FGmaskComp',FGmaskComp)

cv2.moveWindow('FGmaskComp',0,530)

_,contours,_=cv2.findContours(FGmaskComp,cv2.RETR_EXTERNAL,cv2.CHAIN_APPROX_SIMPLE)

contours=sorted(contours,key=lambda x:cv2.contourArea(x),reverse=True)

for cnt in contours:

area=cv2.contourArea(cnt)

(x,y,w,h)=cv2.boundingRect(cnt)

if area>=50:

#cv2.drawContours(frame,[cnt],0,(255,0,0),3)

cv2.rectangle(frame,(x,y),(x+w,y+h),(255,0,0),3)

objX=x+w/2

objY=y+h/2

errorPan=objX-width/2

errorTilt=objY-height/2

if abs(errorPan)>15:

pan=pan-errorPan/75

if abs(errorTilt)>15:

tilt=tilt-errorTilt/75

if pan>180:

pan=180

print("Pan Out of Range")

if pan<0:

pan=0

print("Pan Out of Range")

if tilt>180:

tilt=180

print("Tilt Out of Range")

if tilt<0:

tilt=0

print("Tilt Out of Range")

kit.servo[0].angle=pan

kit.servo[1].angle=tilt

break

cv2.imshow('nanoCam',frame)

cv2.moveWindow('nanoCam',0,0)

if cv2.waitKey(1)==ord('q'):

break

cam.release()

cv2.destroyAllWindows()

Arduino, Tutorial

Arduino Tutorial 33: Understanding How to Control Servos with a Joystick

October 22, 2019 admin

In this lesson we show you how to precisely control the position of two servos using a joystick. We derive the math equations which will allow you to get smooth and precise control of the servo. We also add a buzzer to the project to create an audible alarm when the button the joystick is pressed.

If you want to follow along at home, you can order the Arduino Kit we are using HERE.

Typically, the servos in electronics kits are not the best ones, but are suitable to learn with. If you want a more stable and better quality servo, this is the one I user in more of my projects: HiTEC

Below is the code we developed in this project.

#include <Servo.h>
Servo Xservo;
Servo Yservo;

int Xpin=A0;
int Ypin=A1;
int Spin=2;
int XSpin=9;
int YSpin=10;
int buzzPin=7;
int WVx;
int WVy;
int Xval;
int Yval;
int Sval;
int dt=200;
void setup() {
  // put your setup code here, to run once:
Serial.begin(9600);
pinMode(Xpin,INPUT);
pinMode(Ypin,INPUT);
pinMode(Spin,INPUT);
pinMode(XSpin,OUTPUT);
pinMode(YSpin,OUTPUT);
pinMode(buzzPin,OUTPUT);

Xservo.attach(XSpin);
Yservo.attach(YSpin);

digitalWrite(Spin,HIGH);
}

void loop() {
 Xval=analogRead(Xpin);
 WVx=(180./1023.)*Xval;
 Yval=analogRead(Ypin);
 WVy=(180./1023.)*Yval;
 Sval=digitalRead(Spin);


 Xservo.write(WVx);
 Yservo.write(WVy);

 if (Sval==0){
  digitalWrite(buzzPin, HIGH);
 }
 else {
  digitalWrite(buzzPin, LOW);
 }


 
 delay(dt);
 Serial.print("X Value = ");
 Serial.print(Xval);
 Serial.print(" Y Value = ");
 Serial.print(Yval);
 Serial.print(" Switch State is ");
 Serial.println(Sval);
}

#include <Servo.h>

Servo Xservo;

Servo Yservo;

int Xpin=A0;

int Ypin=A1;

int Spin=2;

int XSpin=9;

int YSpin=10;

int buzzPin=7;

int WVx;

int WVy;

int Xval;

int Yval;

int Sval;

int dt=200;

void setup() {

// put your setup code here, to run once:

Serial.begin(9600);

pinMode(Xpin,INPUT);

pinMode(Ypin,INPUT);

pinMode(Spin,INPUT);

pinMode(XSpin,OUTPUT);

pinMode(YSpin,OUTPUT);

pinMode(buzzPin,OUTPUT);

Xservo.attach(XSpin);

Yservo.attach(YSpin);

digitalWrite(Spin,HIGH);

}

void loop() {

Xval=analogRead(Xpin);

WVx=(180./1023.)*Xval;

Yval=analogRead(Ypin);

WVy=(180./1023.)*Yval;

Sval=digitalRead(Spin);

Xservo.write(WVx);

Yservo.write(WVy);

if (Sval==0){

digitalWrite(buzzPin, HIGH);

}

else {

digitalWrite(buzzPin, LOW);

}

delay(dt);

Serial.print("X Value = ");

Serial.print(Xval);

Serial.print(" Y Value = ");

Serial.print(Yval);

Serial.print(" Switch State is ");

Serial.println(Sval);

}

Technology Tutorials

Tag Archives: Servos

Jetson Xavier NX Lesson 10: Tracking Multiple Objects of Interest with Servos in OpenCV

Jetson Xavier NX Lesson 9: Tracking Objects with Two Cameras in OpenCV

AI on the Jetson Nano LESSON 32: Tracking an Object with Servos in OpenCV

Arduino Tutorial 33: Understanding How to Control Servos with a Joystick

Making The World a Better Place One High Tech Project at a Time. Enjoy!