In this video we introduce key concepts in the area of Machine Learning, Deep Neural Networks, and Deep Learning. We use the code below to demonstrate a simple image recognition capability.

import jetson.inference
import jetson.utils
import time
import cv2
import numpy as np
width=1280
height=720
#cam=jetson.utils.gstCamera(width,height,'/dev/video1')
cam=jetson.utils.gstCamera(width,height,'0')
net=jetson.inference.imageNet('googlenet')
timeMark=time.time()
fpsFilter=0
timeMark=time.time()
font=cv2.FONT_HERSHEY_SIMPLEX
while True:
    frame, width, height = cam.CaptureRGBA(zeroCopy=1)
    classID, confidence = net.Classify(frame, width, height)
    item = net.GetClassDesc(classID)
    dt=time.time()-timeMark
    fps=1/dt
    fpsFilter=.95*fpsFilter+.05*fps
    timeMark=time.time()
    frame=jetson.utils.cudaToNumpy(frame,width,height,4)
    frame=cv2.cvtColor(frame, cv2.COLOR_RGBA2BGR).astype(np.uint8)
    cv2.putText(frame,str(round(fpsFilter,1))+'      '+item,(0,30),font,1,(0,0,255),2)
    cv2.imshow('webCam',frame)
    cv2.moveWindow('webCam',0,0)
    if cv2.waitKey(1)==ord('q'):
        break
cam.release()
cv2.destroyAllWindows()

import jetson.inference

import jetson.utils

import time

import cv2

import numpy as np

width=1280

height=720

#cam=jetson.utils.gstCamera(width,height,'/dev/video1')

cam=jetson.utils.gstCamera(width,height,'0')

net=jetson.inference.imageNet('googlenet')

timeMark=time.time()

fpsFilter=0

timeMark=time.time()

font=cv2.FONT_HERSHEY_SIMPLEX

while True:

frame, width, height = cam.CaptureRGBA(zeroCopy=1)

classID, confidence = net.Classify(frame, width, height)

item = net.GetClassDesc(classID)

dt=time.time()-timeMark

fps=1/dt

fpsFilter=.95*fpsFilter+.05*fps

timeMark=time.time()

frame=jetson.utils.cudaToNumpy(frame,width,height,4)

frame=cv2.cvtColor(frame, cv2.COLOR_RGBA2BGR).astype(np.uint8)

cv2.putText(frame,str(round(fpsFilter,1))+' '+item,(0,30),font,1,(0,0,255),2)

cv2.imshow('webCam',frame)

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

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

break

cam.release()

cv2.destroyAllWindows()

Elegoo Smart Car Tutorial

Robotics Training LESSON 5: Programming Core DC Motor Control Functions

July 9, 2020 admin

In this video tutorial, we show how to program the Elegoo Smart Car 3 to have simple core capabilities. We create code that will move the car forward or backward by a user defined distance. We also have functions that allow the car to turn by a user defined angle. With these simple functions, we can program the car to move along a path we define. Below is the code we developed in this video.

int ENA=5; 
int ENB=6; 
int IN1=7; 
int IN2=8; 
int IN3=9; 
int IN4=11; 
float d; 
int degRot; 
void setup() { 
  // put your setup code here, to run once: 
  Serial.begin(9600); 
  pinMode(ENA,OUTPUT); 
  pinMode(ENB,OUTPUT); 
  pinMode(IN1,OUTPUT); 
  pinMode(IN2,OUTPUT); 
  pinMode(IN3,OUTPUT); 
  pinMode(IN4,OUTPUT); 
  digitalWrite(ENA,HIGH); 
  digitalWrite(ENB,HIGH); 
  } 
  void loop() { 
    forward(10); 
    turnRight(180); 
    forward(10); 
    turnLeft(180); 
    while(1==1){ } 
    } 
    void forward(float d){ 
      float t; 
      digitalWrite(IN1,HIGH); 
      digitalWrite(IN2,LOW); 
      digitalWrite(IN3,LOW); 
      digitalWrite(IN4,HIGH); 
      t=d/2.45*1000; 
      delay(t); 
      stopCar(); 
      } 
      void backward(float d){ 
      float t; 
      digitalWrite(IN1,LOW); 
      digitalWrite(IN2,HIGH); 
      digitalWrite(IN3,HIGH); 
      digitalWrite(IN4,LOW); 
      t=d/2.45*1000; delay(t); 
      stopCar(); 
      } 
      void turnRight(int deg){ 
        float t; 
        digitalWrite(IN1,HIGH); 
        digitalWrite(IN2,LOW); 
        digitalWrite(IN3,HIGH); 
        digitalWrite(IN4,LOW); 
        t=deg/345.*1000.; 
        Serial.println(deg); 
        delay(t); stopCar(); 
        } 
        void turnLeft(float deg){ 
          float t; 
          digitalWrite(IN1,LOW); 
          digitalWrite(IN2,HIGH); 
          digitalWrite(IN3,LOW); 
          digitalWrite(IN4,HIGH); 
          t=deg/345.*1000.; 
          Serial.println(deg); 
          delay(t); stopCar(); 
          } 
          void stopCar(){ 
            digitalWrite(IN1,LOW); 
            digitalWrite(IN2,LOW); 
            digitalWrite(IN3,LOW); 
            digitalWrite(IN4,LOW); 
            } 
            void calF(){ 
             digitalWrite(IN1,HIGH); 
             digitalWrite(IN2,LOW); 
             digitalWrite(IN3,LOW); 
             digitalWrite(IN4,HIGH); 
             delay(5000); stopCar(); 
             } 
             void calB(){ 
              digitalWrite(IN1,LOW); 
              digitalWrite(IN2,HIGH); 
              digitalWrite(IN3,HIGH); 
              digitalWrite(IN4,LOW); 
              delay(5000); 
              stopCar(); 
              } 
              void calR(){ 
                digitalWrite(IN1,HIGH); 
                digitalWrite(IN2,LOW); 
                digitalWrite(IN3,HIGH); 
                digitalWrite(IN4,LOW); 
                delay(5000); stopCar(); 
                } 
                void calL(){ 
                  digitalWrite(IN1,LOW); 
                  digitalWrite(IN2,HIGH); 
                  digitalWrite(IN3,LOW); 
                  digitalWrite(IN4,HIGH); 
                  delay(5000); 
                  stopCar(); 
                  }
}

100

101

102

103

int ENA=5;

int ENB=6;

int IN1=7;

int IN2=8;

int IN3=9;

int IN4=11;

float d;

int degRot;

void setup() {

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

Serial.begin(9600);

pinMode(ENA,OUTPUT);

pinMode(ENB,OUTPUT);

pinMode(IN1,OUTPUT);

pinMode(IN2,OUTPUT);

pinMode(IN3,OUTPUT);

pinMode(IN4,OUTPUT);

digitalWrite(ENA,HIGH);

digitalWrite(ENB,HIGH);

}

void loop() {

forward(10);

turnRight(180);

forward(10);

turnLeft(180);

while(1==1){ }

}

void forward(float d){

float t;

digitalWrite(IN1,HIGH);

digitalWrite(IN2,LOW);

digitalWrite(IN3,LOW);

digitalWrite(IN4,HIGH);

t=d/2.45*1000;

delay(t);

stopCar();

}

void backward(float d){

float t;

digitalWrite(IN1,LOW);

digitalWrite(IN2,HIGH);

digitalWrite(IN3,HIGH);

digitalWrite(IN4,LOW);

t=d/2.45*1000; delay(t);

stopCar();

}

void turnRight(int deg){

float t;

digitalWrite(IN1,HIGH);

digitalWrite(IN2,LOW);

digitalWrite(IN3,HIGH);

digitalWrite(IN4,LOW);

t=deg/345.*1000.;

Serial.println(deg);

delay(t); stopCar();

}

void turnLeft(float deg){

float t;

digitalWrite(IN1,LOW);

digitalWrite(IN2,HIGH);

digitalWrite(IN3,LOW);

digitalWrite(IN4,HIGH);

t=deg/345.*1000.;

Serial.println(deg);

delay(t); stopCar();

}

void stopCar(){

digitalWrite(IN1,LOW);

digitalWrite(IN2,LOW);

digitalWrite(IN3,LOW);

digitalWrite(IN4,LOW);

}

void calF(){

digitalWrite(IN1,HIGH);

digitalWrite(IN2,LOW);

digitalWrite(IN3,LOW);

digitalWrite(IN4,HIGH);

delay(5000); stopCar();

}

void calB(){

digitalWrite(IN1,LOW);

digitalWrite(IN2,HIGH);

digitalWrite(IN3,HIGH);

digitalWrite(IN4,LOW);

delay(5000);

stopCar();

}

void calR(){

digitalWrite(IN1,HIGH);

digitalWrite(IN2,LOW);

digitalWrite(IN3,HIGH);

digitalWrite(IN4,LOW);

delay(5000); stopCar();

}

void calL(){

digitalWrite(IN1,LOW);

digitalWrite(IN2,HIGH);

digitalWrite(IN3,LOW);

digitalWrite(IN4,HIGH);

delay(5000);

stopCar();

}

Jetson Xavier NX

Jetson Xavier NX Lesson 8: Controlling Dual Pan/Tilt Raspberry Pi Cameras

July 8, 2020 admin

In this lesson we show how to independently control two Raspberry Pi Cameras using servo controlled pan/tilt brackets. This work will serve as the foundation for allowing us to create cameras that scan a room and locate objects of interest.

In this lesson, I am using two pan/tilt camera mounts. You can get the gear I am using on amazon HERE. I suggest purchasing two units.

Then, we also need two Version two raspberry pi cameras. I like the following ones, because they include a neat little acrylic case, and the long cable, which makes it work much better on the pan/tilt bracket. You can get the cameras HERE.

If you do not have a Jetson Xavier NX yet, you can pick up the gear I am using below:

First, you will need the Jetson Xavier NX, which you can get HERE:
You will want a quality, large SD card, I have very good luck with this one HERE:
You will need a camera. I have found that the Jetson Xavier NX works very well with most Logitech Webcams, but these cameras are a little hard to find right now. I suggest the best option if you do not have a logitech webcam is to get the Raspberry Pi Version 2 camera, which works very well. You can pick the camera up HERE.
It is optional, but I have found that it is nice to have an extra, longer cable for the Raspberry Pi camera, which is available HERE. Also, a small case/stand for the camera is nice and you can get the one I use HERE.
The Jetson Nano has a slot for a SSD drive. I really like having the SSD drive attached, and makes it much easier to keep your work backed up. The projects in these lessons will work fine with just the SD card, but if you like, the SSD drive makes life easier (note even with SSD drive, you will still need the SD card above). You can get the SSD drive I am using HERE.
You can use USB keyboard and mouse, but I like to preserve my USB slots for other things, so like using a wireless keyboard and mouse. This is optional, but I have found these work well on the Jetson Xavier NX, and you can get what I am using HERE.
You will need an HDMI cable and monitor, which you probably already have.

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

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()
    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)
    print('fps: ',fps)
    #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
cam.release()
cv2.destroyAllWindows()

import cv2

import numpy as np

import time

from adafruit_servokit import ServoKit

print(cv2.__version__)

timeMark=time.time()

dtFIL=0

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()

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)

print('fps: ',fps)

#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

cam.release()

cv2.destroyAllWindows()

Elegoo Smart Car Tutorial

ROBOTICS Training LESSON 4: Fundamentals of Robot Motor Control Using L298N Module

July 2, 2020 admin

In the video tutorial above we describe the fundamentals of Robot Motor Control Using the L298N control module. This establishes the core functions that will be used throughout the remainder of these lessons. We show how we can create the core motion components of forward, backward, turn left and turn right. The code developed in the lesson above is presented below for your convenience. If you would like to play along at home, you can get the hardware I am using HERE:

int ENA=5;
int ENB=6;
int IN1=7;
int IN2=8;
int IN3=9;
int IN4=11;
void setup() {
  // put your setup code here, to run once:
pinMode(ENA,OUTPUT);
pinMode(ENB,OUTPUT);
pinMode(IN1,OUTPUT);
pinMode(IN2,OUTPUT);
pinMode(IN3,OUTPUT);
pinMode(IN4,OUTPUT);
digitalWrite(ENA,HIGH);
digitalWrite(ENB,HIGH);
}

void loop() {
  // Right Turn
digitalWrite(IN1,HIGH);
digitalWrite(IN2,LOW);
digitalWrite(IN3,HIGH);
digitalWrite(IN4,LOW);
delay(1000);
//Left Turn
digitalWrite(IN1,LOW);
digitalWrite(IN2,HIGH);
digitalWrite(IN3,LOW);
digitalWrite(IN4,HIGH);
delay(1000);
//forward
digitalWrite(IN1,HIGH);
digitalWrite(IN2,LOW);
digitalWrite(IN3,LOW);
digitalWrite(IN4,HIGH);
delay(1000);
//backwards
digitalWrite(IN1,LOW);
digitalWrite(IN2,HIGH);
digitalWrite(IN3,HIGH);
digitalWrite(IN4,LOW);
delay(1000);
}

int ENA=5;

int ENB=6;

int IN1=7;

int IN2=8;

int IN3=9;

int IN4=11;

void setup() {

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

pinMode(ENA,OUTPUT);

pinMode(ENB,OUTPUT);

pinMode(IN1,OUTPUT);

pinMode(IN2,OUTPUT);

pinMode(IN3,OUTPUT);

pinMode(IN4,OUTPUT);

digitalWrite(ENA,HIGH);

digitalWrite(ENB,HIGH);

}

void loop() {

// Right Turn

digitalWrite(IN1,HIGH);

digitalWrite(IN2,LOW);

digitalWrite(IN3,HIGH);

digitalWrite(IN4,LOW);

delay(1000);

//Left Turn

digitalWrite(IN1,LOW);

digitalWrite(IN2,HIGH);

digitalWrite(IN3,LOW);

digitalWrite(IN4,HIGH);

delay(1000);

//forward

digitalWrite(IN1,HIGH);

digitalWrite(IN2,LOW);

digitalWrite(IN3,LOW);

digitalWrite(IN4,HIGH);

delay(1000);

//backwards

digitalWrite(IN1,LOW);

digitalWrite(IN2,HIGH);

digitalWrite(IN3,HIGH);

digitalWrite(IN4,LOW);

delay(1000);

}

Jetson Xavier NX

Jetson Xavier NX Lesson 7: Connecting and Controlling Servos

July 1, 2020 admin

In this lesson we show you how to control a pan/tilt camera bracket with the NVIDIA Jetson Xavier NX. We go through the physical build of the bracket, how to connect the circuit, and then how to program the servos. We use the Adafruit circuitpython library, and show how to download and use the library. If you want to play along at home, you can pick the pan/tilt bracket and servos up HERE, and you can grab a couple of Raspberry Pi cameras HERE.

Below is the simple code for moving the servo using the Jetson Xavier NX:

import time
from adafruit_servokit import ServoKit
kit=ServoKit(channels=16)
tilt=125
pan=0
kit.servo[0].angle=pan
kit.servo[1].angle=tilt
for i in range(0,180):
    kit.servo[0].angle=i
    time.sleep(.05)
for i in range(180,0,-1):
    kit.servo[0].angle=i
    time.sleep(.05)
for i in range(45,180):
    kit.servo[1].angle=i
    time.sleep(.05)
for i in range(180,0,-1):
    kit.servo[1].angle=i
    time.sleep(.05)

import time

from adafruit_servokit import ServoKit

kit=ServoKit(channels=16)

tilt=125

pan=0

kit.servo[0].angle=pan

kit.servo[1].angle=tilt

for i in range(0,180):

kit.servo[0].angle=i

time.sleep(.05)

for i in range(180,0,-1):

kit.servo[0].angle=i

time.sleep(.05)

for i in range(45,180):

kit.servo[1].angle=i

time.sleep(.05)

for i in range(180,0,-1):

kit.servo[1].angle=i

time.sleep(.05)

Technology Tutorials

AI on the Jetson Nano LESSON 50: Introduction to Deep Learning and Deep Neural Networks

Robotics Training LESSON 5: Programming Core DC Motor Control Functions

Jetson Xavier NX Lesson 8: Controlling Dual Pan/Tilt Raspberry Pi Cameras

ROBOTICS Training LESSON 4: Fundamentals of Robot Motor Control Using L298N Module

Jetson Xavier NX Lesson 7: Connecting and Controlling Servos

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

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

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