Category Archives: Raspberry Pi

In this video lesson we create an interesting project. We create a PyQt Window which used 3 Sine Waves offset from each other by (2*Pi/). By offsetting the Sine Waves each by this amount creates 3 waves perfectly spaced across the domain. We then use the values from these sine waves to create the Red, Green and Blue values for the HSV color wheel. The x axis represents angle, in radians. Then the values of the sine wave represent the corresponding Red, Green, and Blue values. The program graphs the three waves on the PyQt widget, then passes the data via UDP over WiFi to the Pi Pico. The Pico then applies the values to the RGB LED. We save the server side program on the Pi Pico as main.py, and power the project with the Breadboard Power Bank, meaning the Pi operates remote and untethered, and the LED is controlled by the desktop client software. This is a schematic of the Pi Pico circuit for the project.

Circuit Schematic for Connecting the RGB LED

This project has a server running on the Raspberry Pi Pico, and a Client running on your desktop PC. Here is the code for the server side for the Pi Pico.

import network
import usocket as socket
import secrets
import time
from machine import Pin,PWM

redLED=PWM(Pin(20))
greenLED=PWM(Pin(19))
blueLED=PWM(Pin(18))

redLED.freq(1000)
greenLED.freq(1000)
blueLED.freq(1000)

# Set up WiFi connection
wlan = network.WLAN(network.STA_IF)
wlan.active(True)
print(secrets.SSID,secrets.PASSWORD)
wlan.connect(secrets.SSID,secrets.PASSWORD)

# Wait for connection
while not wlan.isconnected():
    time.sleep(1)
print("Connection Completed")
print('WiFi connected')
print(wlan.ifconfig())

# Set up UDP server
server_socket = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
server_socket.bind((wlan.ifconfig()[0], 12345))
print("Server is Up and Listening")
print(wlan.ifconfig()[0])

while True:
    print('Waiting for a request from the client...')
    # Receive request from client
    myColor, client_address = server_socket.recvfrom(1024)
    myColor=myColor.decode()
    print("Client Request:",myColor)
    print("FROM CLIENT",client_address)
    colorArray=myColor.split(',')
    r=int(colorArray[0])
    g=int(colorArray[1])
    b=int(colorArray[2])
    print(r,g,b)
    redLED.duty_u16(int((r/255)*65535))
    greenLED.duty_u16(int((g/255)*65535))
    blueLED.duty_u16(int((b/255)*65535))
    print("Client Request: ",myColor)
    print("From Client",client_address)
    data="LED "+myColor+" executed"
    server_socket.sendto(data.encode(), client_address)
    print("Data Sent")

import network

import usocket as socket

import secrets

import time

from machine import Pin,PWM

redLED=PWM(Pin(20))

greenLED=PWM(Pin(19))

blueLED=PWM(Pin(18))

redLED.freq(1000)

greenLED.freq(1000)

blueLED.freq(1000)

# Set up WiFi connection

wlan = network.WLAN(network.STA_IF)

wlan.active(True)

print(secrets.SSID,secrets.PASSWORD)

wlan.connect(secrets.SSID,secrets.PASSWORD)

# Wait for connection

while not wlan.isconnected():

time.sleep(1)

print("Connection Completed")

print('WiFi connected')

print(wlan.ifconfig())

# Set up UDP server

server_socket = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)

server_socket.bind((wlan.ifconfig()[0], 12345))

print("Server is Up and Listening")

print(wlan.ifconfig()[0])

while True:

print('Waiting for a request from the client...')

# Receive request from client

myColor, client_address = server_socket.recvfrom(1024)

myColor=myColor.decode()

print("Client Request:",myColor)

print("FROM CLIENT",client_address)

colorArray=myColor.split(',')

r=int(colorArray[0])

g=int(colorArray[1])

b=int(colorArray[2])

print(r,g,b)

redLED.duty_u16(int((r/255)*65535))

greenLED.duty_u16(int((g/255)*65535))

blueLED.duty_u16(int((b/255)*65535))

print("Client Request: ",myColor)

print("From Client",client_address)

data="LED "+myColor+" executed"

server_socket.sendto(data.encode(), client_address)

print("Data Sent")

Remember you must set up your ‘secrets.py’ file for your WiFi name and password. Create this file, put in your WiFi name and password, and then save the file on your Raspberry Pi Pico in the lib folder.

SSID="YOUR WIFI NAME"
PASSWORD="YOUR WIFI PASSWORD"

1 2	SSID="YOUR WIFI NAME" PASSWORD="YOUR WIFI PASSWORD"

Then the code below is the program we developed for the client side. This will run on your PC.

import sys
import socket
import numpy as np
import pyqtgraph as pg
from PyQt5.QtWidgets import *
from PyQt5.QtCore import *

client_socket = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
server_address = ('192.168.88.71',12345)
client_socket.settimeout(1.0)

numPoints = 200
xStart = 0
xStop = 4*np.pi

frequency = 1
Inc = (2*np.pi/numPoints)

count=0
incR=0
incG=0

x=np.linspace(xStart,xStop,numPoints)
ySin=255*np.sin(frequency*x)/2 + 255/2
ySin2 = 255*np.sin(frequency*x + 2*np.pi/3)/2+255/2
ySin3 = 255*np.sin(frequency*x + 4*np.pi/3)/2+255/2

def updatePlot():
    global numPoint,xStart,xStop,Inc,frequency,count
    xStart=xStart + Inc
    xStop=xStop + Inc
    x =np.linspace(xStart, xStop , numPoints)
    ySin=255*np.sin(frequency*x+count*incR/100*frequency)/2+255/2
    ySin2 = 255*np.sin(frequency*x + 2*np.pi/3+count*incG/100*frequency)/2+255/2
    ySin3 = 255*np.sin(frequency*x + 4*np.pi/3)/2+255/2
    
    plotSin.setData(x, ySin)
    plotSin2.setData(x, ySin2)
    plotSin3.setData(x, ySin3)
    
    count=count+1
    
    myColor=str(int(ySin[numPoints-1]))+","+str(int(ySin2[numPoints-1]))+","+str(int(ySin3[numPoints-1]))
    client_socket.sendto(myColor.encode(),server_address)
    try:
        data, addr =client_socket.recvfrom(1024)
        print('Received data: ',data.decode())
    except socket.timeout:
        print("Request timed out. No Response from Server")
    except Exception as e:
        print("An Error Occured")
def updateFrequency(value):
    global frequency, sliderLabel
    frequency = value/10
    sliderLabel.setText("Frequency: "+str(frequency)+" Hz")
def toggleChase(state):
    global incR,incG
    if state==0:
        incR=0
        incG=0
    if state==2:
        incR=1
        incG=2

app=QApplication(sys.argv)
window = QWidget()
window.setWindowTitle("The Magic of Sin Waves")
window.setGeometry(100,100,800,600)
layout = QVBoxLayout(window)

sliderLabel=QLabel("Frequency: 1 Hz")
sliderLabel.setStyleSheet("font-size: 40px;")
layout.addWidget(sliderLabel)

slider = QSlider(Qt.Horizontal)
slider.setMinimum(1)
slider.setMaximum(40)
slider.setValue(10)
slider.valueChanged.connect(updateFrequency)
layout.addWidget(slider)

graphWidget =pg.PlotWidget()
layout.addWidget(graphWidget)
plotSin=graphWidget.plot(x,ySin,pen=pg.mkPen('r',width=4))
plotSin2=graphWidget.plot(x,ySin2,pen=pg.mkPen('g',width=4))
plotSin3=graphWidget.plot(x,ySin3,pen=pg.mkPen('b',width=4))
graphWidget.setYRange(-10,265)

toggleButton=QCheckBox("Chase Mode")
toggleButton.stateChanged.connect(toggleChase)
layout.addWidget(toggleButton)

timer = QTimer()
timer.timeout.connect(updatePlot)
timer.start(100)

window.setLayout(layout)
window.show()
sys.exit(app.exec_())

import sys

import socket

import numpy as np

import pyqtgraph as pg

from PyQt5.QtWidgets import *

from PyQt5.QtCore import *

client_socket = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)

server_address = ('192.168.88.71',12345)

client_socket.settimeout(1.0)

numPoints = 200

xStart = 0

xStop = 4*np.pi

frequency = 1

Inc = (2*np.pi/numPoints)

count=0

incR=0

incG=0

x=np.linspace(xStart,xStop,numPoints)

ySin=255*np.sin(frequency*x)/2 + 255/2

ySin2 = 255*np.sin(frequency*x + 2*np.pi/3)/2+255/2

ySin3 = 255*np.sin(frequency*x + 4*np.pi/3)/2+255/2

def updatePlot():

global numPoint,xStart,xStop,Inc,frequency,count

xStart=xStart + Inc

xStop=xStop + Inc

x =np.linspace(xStart, xStop , numPoints)

ySin=255*np.sin(frequency*x+count*incR/100*frequency)/2+255/2

ySin2 = 255*np.sin(frequency*x + 2*np.pi/3+count*incG/100*frequency)/2+255/2

ySin3 = 255*np.sin(frequency*x + 4*np.pi/3)/2+255/2

plotSin.setData(x, ySin)

plotSin2.setData(x, ySin2)

plotSin3.setData(x, ySin3)

count=count+1

myColor=str(int(ySin[numPoints-1]))+","+str(int(ySin2[numPoints-1]))+","+str(int(ySin3[numPoints-1]))

client_socket.sendto(myColor.encode(),server_address)

try:

data, addr =client_socket.recvfrom(1024)

print('Received data: ',data.decode())

except socket.timeout:

print("Request timed out. No Response from Server")

except Exception as e:

print("An Error Occured")

def updateFrequency(value):

global frequency, sliderLabel

frequency = value/10

sliderLabel.setText("Frequency: "+str(frequency)+" Hz")

def toggleChase(state):

global incR,incG

if state==0:

incR=0

incG=0

if state==2:

incR=1

incG=2

app=QApplication(sys.argv)

window = QWidget()

window.setWindowTitle("The Magic of Sin Waves")

window.setGeometry(100,100,800,600)

layout = QVBoxLayout(window)

sliderLabel=QLabel("Frequency: 1 Hz")

sliderLabel.setStyleSheet("font-size: 40px;")

layout.addWidget(sliderLabel)

slider = QSlider(Qt.Horizontal)

slider.setMinimum(1)

slider.setMaximum(40)

slider.setValue(10)

slider.valueChanged.connect(updateFrequency)

layout.addWidget(slider)

graphWidget =pg.PlotWidget()

layout.addWidget(graphWidget)

plotSin=graphWidget.plot(x,ySin,pen=pg.mkPen('r',width=4))

plotSin2=graphWidget.plot(x,ySin2,pen=pg.mkPen('g',width=4))

plotSin3=graphWidget.plot(x,ySin3,pen=pg.mkPen('b',width=4))

graphWidget.setYRange(-10,265)

toggleButton=QCheckBox("Chase Mode")

toggleButton.stateChanged.connect(toggleChase)

layout.addWidget(toggleButton)

timer = QTimer()

timer.timeout.connect(updatePlot)

timer.start(100)

window.setLayout(layout)

window.show()

sys.exit(app.exec_())

MicroPython, Raspberry Pi, Raspberry Pi Pico

LCD1602 Display Library for Micropython and the Raspberry Pi Pico W

June 12, 2023 admin

This is some demonstration sample code showing use of the LCD1602 as an LCD display for the Raspberry Pi Pico W. The code is explained in the video above. It will prompt a user for his name, and then display a greeting on the LCD.

from lcd1602 import LCD
import utime as time
lcd=LCD()
while True:
    
    myName=input('What is Your Name? ')
    lcd.clear()
    greeting1='Hello '+myName
    greeting2='Welcome to My Pi'
    lcd.write(0,0,greeting1)
    lcd.write(0,1,greeting2)

from lcd1602 import LCD

import utime as time

lcd=LCD()

while True:

myName=input('What is Your Name? ')

lcd.clear()

greeting1='Hello '+myName

greeting2='Welcome to My Pi'

lcd.write(0,0,greeting1)

lcd.write(0,1,greeting2)

Below is the library for the Sunfounder Kepler Kit LCD1602 display. It allows the LCD display to operate with the Raspberry Pi Pico W. The code should be copied and pasted into Thonny, and then saved to your Raspberry Pi Pico W, to the same folder that contains you Python code. It MUST be saved with file name lcd1602.py

import machine
import time

class LCD():
    def __init__(self, addr=None, blen=1):
        sda = machine.Pin(6)
        scl = machine.Pin(7)
        self.bus = machine.I2C(1,sda=sda, scl=scl, freq=400000)
        #print(self.bus.scan())
        self.addr = self.scanAddress(addr)
        self.blen = blen
        self.send_command(0x33) # Must initialize to 8-line mode at first
        time.sleep(0.005)
        self.send_command(0x32) # Then initialize to 4-line mode
        time.sleep(0.005)
        self.send_command(0x28) # 2 Lines & 5*7 dots
        time.sleep(0.005)
        self.send_command(0x0C) # Enable display without cursor
        time.sleep(0.005)
        self.send_command(0x01) # Clear Screen
        self.bus.writeto(self.addr, bytearray([0x08]))

    def scanAddress(self, addr):
        devices = self.bus.scan()
        if len(devices) == 0:
            raise Exception("No LCD found")
        if addr is not None:
            if addr in devices:
                return addr
            else:
                raise Exception(f"LCD at 0x{addr:2X} not found")
        elif 0x27 in devices:
            return 0x27
        elif 0x3F in devices:
            return 0x3F
        else:
            raise Exception("No LCD found")

    def write_word(self, data):
        temp = data
        if self.blen == 1:
            temp |= 0x08
        else:
            temp &= 0xF7
        self.bus.writeto(self.addr, bytearray([temp]))
    
    def send_command(self, cmd):
        # Send bit7-4 firstly
        buf = cmd & 0xF0
        buf |= 0x04               # RS = 0, RW = 0, EN = 1
        self.write_word(buf)
        time.sleep(0.002)
        buf &= 0xFB               # Make EN = 0
        self.write_word(buf)

        # Send bit3-0 secondly
        buf = (cmd & 0x0F) << 4
        buf |= 0x04               # RS = 0, RW = 0, EN = 1
        self.write_word(buf)
        time.sleep(0.002)
        buf &= 0xFB               # Make EN = 0
        self.write_word(buf)
    
    def send_data(self, data):
        # Send bit7-4 firstly
        buf = data & 0xF0
        buf |= 0x05               # RS = 1, RW = 0, EN = 1
        self.write_word(buf)
        time.sleep(0.002)
        buf &= 0xFB               # Make EN = 0
        self.write_word(buf)

        # Send bit3-0 secondly
        buf = (data & 0x0F) << 4
        buf |= 0x05               # RS = 1, RW = 0, EN = 1
        self.write_word(buf)
        time.sleep(0.002)
        buf &= 0xFB               # Make EN = 0
        self.write_word(buf)
    
    def clear(self):
        self.send_command(0x01) # Clear Screen
        
    def openlight(self):  # Enable the backlight
        self.bus.writeto(self.addr,bytearray([0x08]))
        # self.bus.close()
    
    def write(self, x, y, str):
        if x < 0:
            x = 0
        if x > 15:
            x = 15
        if y < 0:
            y = 0
        if y > 1:
            y = 1

        # Move cursor
        addr = 0x80 + 0x40 * y + x
        self.send_command(addr)

        for chr in str:
            self.send_data(ord(chr))
    
    def message(self, text):
        #print("message: %s"%text)
        for char in text:
            if char == '\n':
                self.send_command(0xC0) # next line
            else:
                self.send_data(ord(char))

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import machine

import time

class LCD():

def __init__(self, addr=None, blen=1):

sda = machine.Pin(6)

scl = machine.Pin(7)

self.bus = machine.I2C(1,sda=sda, scl=scl, freq=400000)

#print(self.bus.scan())

self.addr = self.scanAddress(addr)

self.blen = blen

self.send_command(0x33) # Must initialize to 8-line mode at first

time.sleep(0.005)

self.send_command(0x32) # Then initialize to 4-line mode

time.sleep(0.005)

self.send_command(0x28) # 2 Lines & 5*7 dots

time.sleep(0.005)

self.send_command(0x0C) # Enable display without cursor

time.sleep(0.005)

self.send_command(0x01) # Clear Screen

self.bus.writeto(self.addr, bytearray([0x08]))

def scanAddress(self, addr):

devices = self.bus.scan()

if len(devices) == 0:

raise Exception("No LCD found")

if addr is not None:

if addr in devices:

return addr

else:

raise Exception(f"LCD at 0x{addr:2X} not found")

elif 0x27 in devices:

return 0x27

elif 0x3F in devices:

return 0x3F

else:

raise Exception("No LCD found")

def write_word(self, data):

temp = data

if self.blen == 1:

temp |= 0x08

else:

temp &= 0xF7

self.bus.writeto(self.addr, bytearray([temp]))

def send_command(self, cmd):

# Send bit7-4 firstly

buf = cmd & 0xF0

buf |= 0x04 # RS = 0, RW = 0, EN = 1

self.write_word(buf)

time.sleep(0.002)

buf &= 0xFB # Make EN = 0

self.write_word(buf)

# Send bit3-0 secondly

buf = (cmd & 0x0F) << 4

buf |= 0x04 # RS = 0, RW = 0, EN = 1

self.write_word(buf)

time.sleep(0.002)

buf &= 0xFB # Make EN = 0

self.write_word(buf)

def send_data(self, data):

# Send bit7-4 firstly

buf = data & 0xF0

buf |= 0x05 # RS = 1, RW = 0, EN = 1

self.write_word(buf)

time.sleep(0.002)

buf &= 0xFB # Make EN = 0

self.write_word(buf)

# Send bit3-0 secondly

buf = (data & 0x0F) << 4

buf |= 0x05 # RS = 1, RW = 0, EN = 1

self.write_word(buf)

time.sleep(0.002)

buf &= 0xFB # Make EN = 0

self.write_word(buf)

def clear(self):

self.send_command(0x01) # Clear Screen

def openlight(self): # Enable the backlight

self.bus.writeto(self.addr,bytearray([0x08]))

# self.bus.close()

def write(self, x, y, str):

if x < 0:

x = 0

if x > 15:

x = 15

if y < 0:

y = 0

if y > 1:

y = 1

# Move cursor

addr = 0x80 + 0x40 * y + x

self.send_command(addr)

for chr in str:

self.send_data(ord(chr))

def message(self, text):

#print("message: %s"%text)

for char in text:

if char == '\n':

self.send_command(0xC0) # next line

else:

self.send_data(ord(char))

Artificial Intelligence, OpenCV, Raspberry Pi

Raspberry Pi LESSON 63: Object Detection on Raspberry Pi Using Tensorflow Lite

May 25, 2023 admin

In this lesson I show you how to do object detection on the Raspberry Pi using Tensorflow Lite. We will write our first program and by the end of the lesson you will have your Pi detecting objects, boxing them and labeling them in OpenCV.

The video demonstrates step-by-step how to install the tensorflow libraries.

For your convenience I have included the code below we develop in this lesson

import cv2
import time
from picamera2 import Picamera2

from tflite_support.task import core
from tflite_support.task import processor
from tflite_support.task import vision
import utils

model='efficientdet_lite0.tflite'
num_threads=4

dispW=1280
dispH=720

picam2=Picamera2()
picam2.preview_configuration.main.size=(dispW,dispH)
picam2.preview_configuration.main.format='RGB888'
picam2.preview_configuration.align()
picam2.configure("preview")
picam2.start()

webCam='/dev/video2'
cam=cv2.VideoCapture(webCam)
cam.set(cv2.CAP_PROP_FRAME_WIDTH, dispW)
cam.set(cv2.CAP_PROP_FRAME_HEIGHT, dispH)
cam.set(cv2.CAP_PROP_FPS, 30)

pos=(20,60)
font=cv2.FONT_HERSHEY_SIMPLEX
height=1.5
weight=3
myColor=(255,0,0)

fps=0

base_options=core.BaseOptions(file_name=model,use_coral=False, num_threads=num_threads)
detection_options=processor.DetectionOptions(max_results=3, score_threshold=.3)
options=vision.ObjectDetectorOptions(base_options=base_options,detection_options=detection_options)
detector=vision.ObjectDetector.create_from_options(options)
tStart=time.time()
while True:
    ret, im = cam.read()
    #im=picam2.capture_array()
    #im=cv2.flip(im,-1)
    imRGB=cv2.cvtColor(im,cv2.COLOR_BGR2RGB)
    imTensor=vision.TensorImage.create_from_array(imRGB)
    detections=detector.detect(imTensor)
    image=utils.visualize(im, detections)
    cv2.putText(im,str(int(fps))+' FPS',pos,font,height,myColor,weight)
    cv2.imshow('Camera',im)
    if cv2.waitKey(1)==ord('q'):
        break
    tEnd=time.time()
    loopTime=tEnd-tStart
    fps= .9*fps +.1*1/loopTime
    tStart=time.time()
cv2.destroyAllWindows()

import cv2

import time

from picamera2 import Picamera2

from tflite_support.task import core

from tflite_support.task import processor

from tflite_support.task import vision

import utils

model='efficientdet_lite0.tflite'

num_threads=4

dispW=1280

dispH=720

picam2=Picamera2()

picam2.preview_configuration.main.size=(dispW,dispH)

picam2.preview_configuration.main.format='RGB888'

picam2.preview_configuration.align()

picam2.configure("preview")

picam2.start()

webCam='/dev/video2'

cam=cv2.VideoCapture(webCam)

cam.set(cv2.CAP_PROP_FRAME_WIDTH, dispW)

cam.set(cv2.CAP_PROP_FRAME_HEIGHT, dispH)

cam.set(cv2.CAP_PROP_FPS, 30)

pos=(20,60)

font=cv2.FONT_HERSHEY_SIMPLEX

height=1.5

weight=3

myColor=(255,0,0)

fps=0

base_options=core.BaseOptions(file_name=model,use_coral=False, num_threads=num_threads)

detection_options=processor.DetectionOptions(max_results=3, score_threshold=.3)

options=vision.ObjectDetectorOptions(base_options=base_options,detection_options=detection_options)

detector=vision.ObjectDetector.create_from_options(options)

tStart=time.time()

while True:

ret, im = cam.read()

#im=picam2.capture_array()

#im=cv2.flip(im,-1)

imRGB=cv2.cvtColor(im,cv2.COLOR_BGR2RGB)

imTensor=vision.TensorImage.create_from_array(imRGB)

detections=detector.detect(imTensor)

image=utils.visualize(im, detections)

cv2.putText(im,str(int(fps))+' FPS',pos,font,height,myColor,weight)

cv2.imshow('Camera',im)

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

break

tEnd=time.time()

loopTime=tEnd-tStart

fps= .9*fps +.1*1/loopTime

tStart=time.time()

cv2.destroyAllWindows()

OpenCV, Python, Raspberry Pi

Raspberry Pi LESSON 61: Finding and Tracking Faces and Eyes In OpenCV

May 11, 2023 admin

In this video lesson we show how to use Haar Cascades in OpenCV on the Raspberry Pi to find and track faces and eyes. We show the intelligent way to find eyes, such that CPU resources are not wasted. Below we show the code for your convenience.

import cv2
from picamera2 import Picamera2
import time
picam2 = Picamera2()
dispW=1280
dispH=720
picam2.preview_configuration.main.size = (dispW,dispH)
picam2.preview_configuration.main.format = "RGB888"
picam2.preview_configuration.controls.FrameRate=30
picam2.preview_configuration.align()
picam2.configure("preview")
picam2.start()
fps=0
pos=(30,60)
font=cv2.FONT_HERSHEY_SIMPLEX
height=1.5
weight=3
myColor=(0,0,255)

faceCascade=cv2.CascadeClassifier('./haar/haarcascade_frontalface_default.xml')
eyeCascade=cv2.CascadeClassifier('./haar/haarcascade_eye.xml')


while True:
    tStart=time.time()
    frame= picam2.capture_array()
    frame=cv2.flip(frame,-1)
    frameGray=cv2.cvtColor(frame,cv2.COLOR_BGR2GRAY)
    faces=faceCascade.detectMultiScale(frameGray,1.3,5)
    for face in faces:
        x,y,w,h=face
        cv2.rectangle(frame,(x,y),(x+w,y+h),(255,0,0),3)
        roiGray=frameGray[y:y+h,x:x+w]
        roiColor=frame[y:y+h,x:x+w]
        eyes=eyeCascade.detectMultiScale(roiGray,1.3,5)
        for eye in eyes:
            x,y,w,h=eye
            cv2.rectangle(roiColor,(x,y),(x+w,y+h),(255,0,0),3)
    cv2.putText(frame,str(int(fps))+' FPS',pos,font,height,myColor,weight)
    cv2.imshow("Camera", frame)

    if cv2.waitKey(1)==ord('q'):
        break
    tEnd=time.time()
    loopTime=tEnd-tStart
    fps=.9*fps + .1*(1/loopTime)
cv2.destroyAllWindows()

import cv2

from picamera2 import Picamera2

import time

picam2 = Picamera2()

dispW=1280

dispH=720

picam2.preview_configuration.main.size = (dispW,dispH)

picam2.preview_configuration.main.format = "RGB888"

picam2.preview_configuration.controls.FrameRate=30

picam2.preview_configuration.align()

picam2.configure("preview")

picam2.start()

fps=0

pos=(30,60)

font=cv2.FONT_HERSHEY_SIMPLEX

height=1.5

weight=3

myColor=(0,0,255)

faceCascade=cv2.CascadeClassifier('./haar/haarcascade_frontalface_default.xml')

eyeCascade=cv2.CascadeClassifier('./haar/haarcascade_eye.xml')

while True:

tStart=time.time()

frame= picam2.capture_array()

frame=cv2.flip(frame,-1)

frameGray=cv2.cvtColor(frame,cv2.COLOR_BGR2GRAY)

faces=faceCascade.detectMultiScale(frameGray,1.3,5)

for face in faces:

x,y,w,h=face

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

roiGray=frameGray[y:y+h,x:x+w]

roiColor=frame[y:y+h,x:x+w]

eyes=eyeCascade.detectMultiScale(roiGray,1.3,5)

for eye in eyes:

x,y,w,h=eye

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

cv2.putText(frame,str(int(fps))+' FPS',pos,font,height,myColor,weight)

cv2.imshow("Camera", frame)

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

break

tEnd=time.time()

loopTime=tEnd-tStart

fps=.9*fps + .1*(1/loopTime)

cv2.destroyAllWindows()

OpenCV, Python, Raspberry Pi

Raspberry Pi LESSON 59: Improved Pan/Tilt Tracking Control Algorithm

April 27, 2023 admin

In this Video Lesson we show an improved control algorithm for tracking an Object of Interest in OpenCV. We develop a simple example of Proportional control, where the correction signal is proportional to the error signal. We show this is a much improved algorithm over our earlier one, which simply applied 1 degree corrections independent of the size of the error. The code we develop in this lesson is included below for your convenience.

import cv2
from picamera2 import Picamera2
import time
import numpy as np
from servo import Servo
picam2 = Picamera2()

pan=Servo(pin=13)
tilt=Servo(pin=12)

panAngle=0
tiltAngle=0

pan.set_angle(panAngle)
tilt.set_angle(tiltAngle)

dispW=1280
dispH=720
picam2.preview_configuration.main.size = (dispW,dispH)
picam2.preview_configuration.main.format = "RGB888"
picam2.preview_configuration.controls.FrameRate=30
picam2.preview_configuration.align()
picam2.configure("preview")
picam2.start()
fps=0
pos=(30,60)
font=cv2.FONT_HERSHEY_SIMPLEX
height=1.5
weight=3
myColor=(0,0,255)
track=0

def onTrack1(val):
    global hueLow
    hueLow=val
    print('Hue Low',hueLow)
def onTrack2(val):
    global hueHigh
    hueHigh=val
    print('Hue High',hueHigh)
def onTrack3(val):
    global satLow
    satLow=val
    print('Sat Low',satLow)
def onTrack4(val):
    global satHigh
    satHigh=val
    print('Sat High',satHigh)
def onTrack5(val):
    global valLow
    valLow=val
    print('Val Low',valLow)
def onTrack6(val):
    global valHigh
    valHigh=val
    print('Val High',valHigh)
def onTrack7(val):
    global track
    track=val
    print('Track Value',track)

cv2.namedWindow('myTracker')

cv2.createTrackbar('Hue Low','myTracker',10,179,onTrack1)
cv2.createTrackbar('Hue High','myTracker',20,179,onTrack2)
cv2.createTrackbar('Sat Low','myTracker',100,255,onTrack3)
cv2.createTrackbar('Sat High','myTracker',255,255,onTrack4)
cv2.createTrackbar('Val Low','myTracker',100,255,onTrack5)
cv2.createTrackbar('Val High','myTracker',255,255,onTrack6)
cv2.createTrackbar('Train-0 Track-1','myTracker',0,1,onTrack7)


while True:
    tStart=time.time()
    frame= picam2.capture_array()
    frame=cv2.flip(frame,-1)
    frameHSV=cv2.cvtColor(frame,cv2.COLOR_BGR2HSV)
    cv2.putText(frame,str(int(fps))+' FPS',pos,font,height,myColor,weight)
    lowerBound=np.array([hueLow,satLow,valLow])
    upperBound=np.array([hueHigh,satHigh,valHigh])
    myMask=cv2.inRange(frameHSV,lowerBound,upperBound)
    myMaskSmall=cv2.resize(myMask,(int(dispW/2),int(dispH/2)))
    myObject=cv2.bitwise_and(frame,frame, mask=myMask)
    myObjectSmall=cv2.resize(myObject,(int(dispW/2),int(dispH/2)))
    
    contours,junk=cv2.findContours(myMask,cv2.RETR_EXTERNAL,cv2.CHAIN_APPROX_SIMPLE)
    if len(contours)>0:
        contours=sorted(contours,key=lambda x:cv2.contourArea(x),reverse=True)
        #cv2.drawContours(frame,contours,-1,(255,0,0),3)
        contour=contours[0]
        x,y,w,h=cv2.boundingRect(contour)
        cv2.rectangle(frame,(x,y),(x+w,y+h),(0,0,255),3)
        if track==1:
            error=(x+w/2)-dispW/2
            panAngle=panAngle-error/75
            if panAngle>90:
                panAngle=90
            if panAngle<-90:
                panAngle=-90
            if abs(error)>35:
                pan.set_angle(panAngle)
            tiltError=(y+h/2)-dispH/2
            tiltAngle=tiltAngle+tiltError/75
            if tiltAngle>40:
                tiltAngle=40
            if tiltAngle<-90:
                tiltAngle=-90
            if abs(tiltError)>35:
                tilt.set_angle(tiltAngle)
        
    cv2.imshow('Camera',frame)
    cv2.imshow('Mask',myMaskSmall)
    cv2.imshow('My Object',myObjectSmall)
    if cv2.waitKey(1)==ord('q'):
        break
    tEnd=time.time()
    loopTime=tEnd-tStart
    fps=.9*fps + .1*(1/loopTime)
cv2.destroyAllWindows()

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import cv2

from picamera2 import Picamera2

import time

import numpy as np

from servo import Servo

picam2 = Picamera2()

pan=Servo(pin=13)

tilt=Servo(pin=12)

panAngle=0

tiltAngle=0

pan.set_angle(panAngle)

tilt.set_angle(tiltAngle)

dispW=1280

dispH=720

picam2.preview_configuration.main.size = (dispW,dispH)

picam2.preview_configuration.main.format = "RGB888"

picam2.preview_configuration.controls.FrameRate=30

picam2.preview_configuration.align()

picam2.configure("preview")

picam2.start()

fps=0

pos=(30,60)

font=cv2.FONT_HERSHEY_SIMPLEX

height=1.5

weight=3

myColor=(0,0,255)

track=0

def onTrack1(val):

global hueLow

hueLow=val

print('Hue Low',hueLow)

def onTrack2(val):

global hueHigh

hueHigh=val

print('Hue High',hueHigh)

def onTrack3(val):

global satLow

satLow=val

print('Sat Low',satLow)

def onTrack4(val):

global satHigh

satHigh=val

print('Sat High',satHigh)

def onTrack5(val):

global valLow

valLow=val

print('Val Low',valLow)

def onTrack6(val):

global valHigh

valHigh=val

print('Val High',valHigh)

def onTrack7(val):

global track

track=val

print('Track Value',track)

cv2.namedWindow('myTracker')

cv2.createTrackbar('Hue Low','myTracker',10,179,onTrack1)

cv2.createTrackbar('Hue High','myTracker',20,179,onTrack2)

cv2.createTrackbar('Sat Low','myTracker',100,255,onTrack3)

cv2.createTrackbar('Sat High','myTracker',255,255,onTrack4)

cv2.createTrackbar('Val Low','myTracker',100,255,onTrack5)

cv2.createTrackbar('Val High','myTracker',255,255,onTrack6)

cv2.createTrackbar('Train-0 Track-1','myTracker',0,1,onTrack7)

while True:

tStart=time.time()

frame= picam2.capture_array()

frame=cv2.flip(frame,-1)

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

cv2.putText(frame,str(int(fps))+' FPS',pos,font,height,myColor,weight)

lowerBound=np.array([hueLow,satLow,valLow])

upperBound=np.array([hueHigh,satHigh,valHigh])

myMask=cv2.inRange(frameHSV,lowerBound,upperBound)

myMaskSmall=cv2.resize(myMask,(int(dispW/2),int(dispH/2)))

myObject=cv2.bitwise_and(frame,frame, mask=myMask)

myObjectSmall=cv2.resize(myObject,(int(dispW/2),int(dispH/2)))

contours,junk=cv2.findContours(myMask,cv2.RETR_EXTERNAL,cv2.CHAIN_APPROX_SIMPLE)

if len(contours)>0:

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

#cv2.drawContours(frame,contours,-1,(255,0,0),3)

contour=contours[0]

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

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

if track==1:

error=(x+w/2)-dispW/2

panAngle=panAngle-error/75

if panAngle>90:

panAngle=90

if panAngle<-90:

panAngle=-90

if abs(error)>35:

pan.set_angle(panAngle)

tiltError=(y+h/2)-dispH/2

tiltAngle=tiltAngle+tiltError/75

if tiltAngle>40:

tiltAngle=40

if tiltAngle<-90:

tiltAngle=-90

if abs(tiltError)>35:

tilt.set_angle(tiltAngle)

cv2.imshow('Camera',frame)

cv2.imshow('Mask',myMaskSmall)

cv2.imshow('My Object',myObjectSmall)

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

break

tEnd=time.time()

loopTime=tEnd-tStart

fps=.9*fps + .1*(1/loopTime)

cv2.destroyAllWindows()

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Category Archives: Raspberry Pi

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Raspberry Pi LESSON 59: Improved Pan/Tilt Tracking Control Algorithm

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