Tag Archives: Python

In this video lesson we show how we can send and receive data between the Raspberry Pi Pico W, and your PC. We will be running python on the PC, and we will exchange data using the UDP protocol. UDP is simple, and a very reliable way to send data packets back and forth. In this example, we will be demonstrating a simple Client Server relationship between the Pi Pico and PC using UDP over WiFi.

For your convenience, this is the “Server” software you will run on the Pi Pico.

import network
import usocket as socket
import secrets
import time

wlan = network.WLAN(network.STA_IF)
wlan.active(True)
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
    request, client_address = server_socket.recvfrom(1024)
    print("Client Request:",request.decode())
    print("FROM CLIENT",client_address)
    
    # String to send
    data = "225,128,64"
    
    # Send data to client
    server_socket.sendto(data.encode(), client_address)
    print(f'Sent data to {client_address}')
    
    # Optional: Pause for a short period to prevent overwhelming the client
    time.sleep(1)

import network

import usocket as socket

import secrets

import time

wlan = network.WLAN(network.STA_IF)

wlan.active(True)

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

request, client_address = server_socket.recvfrom(1024)

print("Client Request:",request.decode())

print("FROM CLIENT",client_address)

# String to send

data = "225,128,64"

# Send data to client

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

print(f'Sent data to {client_address}')

# Optional: Pause for a short period to prevent overwhelming the client

time.sleep(1)

Notice that the above code wants to load a “secrets” file that contain your WiFi name, and password

You should edit the code below with your WiFi username and your password, and then save the file in the Pi Pico lib folder, with the name secrets.py (don’t forget the .py)

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

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

Now, on the PC side, you will run your client, which will be run in Python. Here is the client software:

import socket
import time

# Set up UDP client
client_socket = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
server_address = ('192.168.88.71', 12345)  # Adjust IP address and port as needed

while True:
    # Send request to the server
    request_message = "SEND DATA"
    client_socket.sendto(request_message.encode(), server_address)
    
    # Receive data from the server
    data, addr = client_socket.recvfrom(1024)
    print('Received data:', data.decode())
    
    # Send acknowledgment back to server
    #ack_message = "Data received successfully"
    #client_socket.sendto(ack_message.encode(), addr)
    
    # Wait for 10 seconds before next request
    time.sleep(10)

import socket

import time

# Set up UDP client

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

server_address = ('192.168.88.71', 12345) # Adjust IP address and port as needed

while True:

# Send request to the server

request_message = "SEND DATA"

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

# Receive data from the server

data, addr = client_socket.recvfrom(1024)

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

# Send acknowledgment back to server

#ack_message = "Data received successfully"

#client_socket.sendto(ack_message.encode(), addr)

# Wait for 10 seconds before next request

time.sleep(10)

Python, Raspberry Pi

Library for Reading a 16 Button Keypad on the Raspberry Pi

October 27, 2022 admin

In this lesson we show you how to create a Python Class and Library that allows you to easily get user input on a Raspberry Pi from a 16 button keypad. This will allow very easy interaction with the keypad.

The Library Code which we develop in the video is presented below for your convenience:

class keypad:
    def __init__(self,rows=[11,13,15,29],columns=[31,33,35,37],keyLabels=[['1','2','3','A'],['4','5','6','B'],['7','8','9','C'],['*','0','#','D']],retChar='D'):
        import RPi.GPIO as GPIO
        self.rows=rows
        self.columns=columns
        self.retChar=retChar
        self.keyLabels=keyLabels
        GPIO.setmode(GPIO.BOARD)
        for i in rows:
            GPIO.setup(i,GPIO.OUT)
        for j in columns:
            GPIO.setup(j,GPIO.IN,pull_up_down=GPIO.PUD_DOWN)
    def readKeypad(self):
        from time import sleep
        import RPi.GPIO as GPIO
        keyStrokes=''
        noPress=True
        noPressOld=True
        while True:
            noPress=True
            for myRow in [0,1,2,3]:
                for myColumn in [0,1,2,3]:
                    GPIO.output(self.rows[myRow],GPIO.HIGH)
                    butVal=GPIO.input(self.columns[myColumn])
                    GPIO.output(self.rows[myRow],GPIO.LOW)
                    if butVal==1:
                        myChar=self.keyLabels[myRow][myColumn]
                        if myChar==self.retChar:
                            return keyStrokes
                        noPress=False
                    if butVal==1 and noPressOld==True and noPress==False:
                        keyStrokes=keyStrokes+myChar
            noPressOld=noPress
            sleep(.25)

class keypad:

def __init__(self,rows=[11,13,15,29],columns=[31,33,35,37],keyLabels=[['1','2','3','A'],['4','5','6','B'],['7','8','9','C'],['*','0','#','D']],retChar='D'):

import RPi.GPIO as GPIO

self.rows=rows

self.columns=columns

self.retChar=retChar

self.keyLabels=keyLabels

GPIO.setmode(GPIO.BOARD)

for i in rows:

GPIO.setup(i,GPIO.OUT)

for j in columns:

GPIO.setup(j,GPIO.IN,pull_up_down=GPIO.PUD_DOWN)

def readKeypad(self):

from time import sleep

import RPi.GPIO as GPIO

keyStrokes=''

noPress=True

noPressOld=True

while True:

noPress=True

for myRow in [0,1,2,3]:

for myColumn in [0,1,2,3]:

GPIO.output(self.rows[myRow],GPIO.HIGH)

butVal=GPIO.input(self.columns[myColumn])

GPIO.output(self.rows[myRow],GPIO.LOW)

if butVal==1:

myChar=self.keyLabels[myRow][myColumn]

if myChar==self.retChar:

return keyStrokes

noPress=False

if butVal==1 and noPressOld==True and noPress==False:

keyStrokes=keyStrokes+myChar

noPressOld=noPress

sleep(.25)

To use this code as a library, save it in the same folder as your python programs, and save it as KPLIB.py

import RPi.GPIO as GPIO
from KPLIB import keypad
myPad=keypad(retChar='A')
myString=myPad.readKeypad()
print(myString)
GPIO.cleanup()

import RPi.GPIO as GPIO

from KPLIB import keypad

myPad=keypad(retChar='A')

myString=myPad.readKeypad()

print(myString)

GPIO.cleanup()

This is a simple demo program that calls the library above, to receive input from the keypad.

3D Graphics with Visual Python, Arduino with Python

Using an Arduino with Python LESSON 14: Model a Moving Marble in a Room Using Parameters

April 12, 2022 admin

In this lesson we show how to model a moving marble in vPython. We show how to create an animation where the marble bounces off the left and righty walls of our virtual room. For your convenience, we include the code below:

from vpython import *
roomX=12
roomY=10
roomZ=16
wallT=.5
wallColor=vector(1,1,1)
wallOpacity=.8
frontOpacity=.1
marbleR=.5
ballColor=vector(0,0,1)

myFloor=box(size=vector(roomX,wallT,roomZ),pos=vector(0,-roomY/2,0),color=wallColor,opacity=wallOpacity)
myCeiling=box(size=vector(roomX,wallT,roomZ),pos=vector(0,roomY/2,0),color=wallColor,opacity=wallOpacity)
leftWall=box(size=vector(wallT,roomY,roomZ),pos=vector(-roomX/2,0,0),color=wallColor,opacity=wallOpacity)
rightWall=box(size=vector(wallT,roomY,roomZ),pos=vector(roomX/2,0,0),color=wallColor,opacity=wallOpacity)
backWall=box(size=vector(roomX,roomY,wallT),pos=vector(0,0,-roomZ/2),color=wallColor,opacity=wallOpacity)
frontWall=box(size=vector(roomX,roomY,wallT),pos=vector(0,0,roomZ/2),color=wallColor,opacity=frontOpacity)
marble=sphere(color=ballColor,radius=marbleR)

marbleX=0
deltaX=.1

while True:
    rate(20)
    marbleX=marbleX+deltaX
    if marbleX+marbleR>(roomX/2-wallT/2) or marbleX-marbleR<(-roomX/2+wallT/2):
        deltaX=deltaX*(-1)
        marbleX=marbleX+deltaX
    marble.pos=vector(marbleX,0,0)

from vpython import *

roomX=12

roomY=10

roomZ=16

wallT=.5

wallColor=vector(1,1,1)

wallOpacity=.8

frontOpacity=.1

marbleR=.5

ballColor=vector(0,0,1)

myFloor=box(size=vector(roomX,wallT,roomZ),pos=vector(0,-roomY/2,0),color=wallColor,opacity=wallOpacity)

myCeiling=box(size=vector(roomX,wallT,roomZ),pos=vector(0,roomY/2,0),color=wallColor,opacity=wallOpacity)

leftWall=box(size=vector(wallT,roomY,roomZ),pos=vector(-roomX/2,0,0),color=wallColor,opacity=wallOpacity)

rightWall=box(size=vector(wallT,roomY,roomZ),pos=vector(roomX/2,0,0),color=wallColor,opacity=wallOpacity)

backWall=box(size=vector(roomX,roomY,wallT),pos=vector(0,0,-roomZ/2),color=wallColor,opacity=wallOpacity)

frontWall=box(size=vector(roomX,roomY,wallT),pos=vector(0,0,roomZ/2),color=wallColor,opacity=frontOpacity)

marble=sphere(color=ballColor,radius=marbleR)

marbleX=0

deltaX=.1

while True:

rate(20)

marbleX=marbleX+deltaX

if marbleX+marbleR>(roomX/2-wallT/2) or marbleX-marbleR<(-roomX/2+wallT/2):

deltaX=deltaX*(-1)

marbleX=marbleX+deltaX

marble.pos=vector(marbleX,0,0)

3D Graphics with Visual Python, Arduino, Arduino with Python, Python

Using an Arduino with Python LESSON 8: Live Thermometer 3D Visual Using DHT11

March 1, 2022 admin

In this video lesson we connect the Arduino to a DHT11 temperature and humidity sensor. We show how to wire the device up, and then how to code the Arduino. The data is passed from the Arduino to python. We then create a live 3D thermometer model that updates as the temperature changes.

On the arduino side, this is the code which we use:

#include "DHT.h"
#define DHTPIN 2
#define DHTTYPE DHT11

float tempF;
float tempC;
float humidity;

int setTime=500;
int dt=1000;

DHT TH(DHTPIN,DHTTYPE);

void setup() {
  // put your setup code here, to run once:
Serial.begin(115200);
TH.begin();
delay(setTime);
}
void loop() {
  // put your main code here, to run repeatedly:
tempC=TH.readTemperature();
tempF=TH.readTemperature(true);
humidity=TH.readHumidity();


Serial.print(tempF);
Serial.print(",");
Serial.println(humidity);

delay(dt);
}

#include "DHT.h"

#define DHTPIN 2

#define DHTTYPE DHT11

float tempF;

float tempC;

float humidity;

int setTime=500;

int dt=1000;

DHT TH(DHTPIN,DHTTYPE);

void setup() {

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

Serial.begin(115200);

TH.begin();

delay(setTime);

}

void loop() {

// put your main code here, to run repeatedly:

tempC=TH.readTemperature();

tempF=TH.readTemperature(true);

humidity=TH.readHumidity();

Serial.print(tempF);

Serial.print(",");

Serial.println(humidity);

delay(dt);

}

Then on the python side, we use the following code:

import time
import serial
from vpython import *

arduinoData=serial.Serial('com3',115200)
time.sleep(.5)
digValue=label(text='50',height=20,box=False,pos=vector(0,-2.5,2))
bulb=sphere(radius=1,color=color.red,pos=vector(0,-3,0))
cyl=cylinder(radius=.6,color=color.red,axis=vector(0,1,0),length=6,pos=vector(0,-3,0))
bulbGlass=sphere(radius=1.2,color=color.white,opacity=.25,pos=vector(0,-3,0))
cylGlass=cylinder(radius=.8,color=color.white,axis=vector(0,1,0),opacity=.25,length=6,pos=vector(0,-3,0))
for temp in range(0,115,10):
    tickPos=4.5/115*temp+1.5
    tick=cylinder(radius=.7,color=color.black,length=.1,axis=vector(0,1,0),pos=vector(0,tickPos-3,0))
    label=text(text=str(temp),color=color.white,pos=vector(-2,tickPos-3,0),height=.3)
while True:
    while arduinoData.in_waiting==0:
        pass
    dataPacket=arduinoData.readline()
    dataPacket=str(dataPacket,'utf-8')
    dataPacket=dataPacket.strip('\r\n')
    dataPacket=dataPacket.split(',')
    temp=float(dataPacket[0])
    hum=float(dataPacket[1])
    len=(4.5/115)*temp+1.5
    cyl.length=len
    digValue.text=str(temp)

import time

import serial

from vpython import *

arduinoData=serial.Serial('com3',115200)

time.sleep(.5)

digValue=label(text='50',height=20,box=False,pos=vector(0,-2.5,2))

bulb=sphere(radius=1,color=color.red,pos=vector(0,-3,0))

cyl=cylinder(radius=.6,color=color.red,axis=vector(0,1,0),length=6,pos=vector(0,-3,0))

bulbGlass=sphere(radius=1.2,color=color.white,opacity=.25,pos=vector(0,-3,0))

cylGlass=cylinder(radius=.8,color=color.white,axis=vector(0,1,0),opacity=.25,length=6,pos=vector(0,-3,0))

for temp in range(0,115,10):

tickPos=4.5/115*temp+1.5

tick=cylinder(radius=.7,color=color.black,length=.1,axis=vector(0,1,0),pos=vector(0,tickPos-3,0))

label=text(text=str(temp),color=color.white,pos=vector(-2,tickPos-3,0),height=.3)

while True:

while arduinoData.in_waiting==0:

pass

dataPacket=arduinoData.readline()

dataPacket=str(dataPacket,'utf-8')

dataPacket=dataPacket.strip('\r\n')

dataPacket=dataPacket.split(',')

temp=float(dataPacket[0])

hum=float(dataPacket[1])

len=(4.5/115)*temp+1.5

cyl.length=len

digValue.text=str(temp)

Artificial Intelligence, OpenCV, Python, Tutorial

Improved Gesture Recognition in Python and MediaPipe

February 10, 2022 admin

In this video lesson we show you how you can improve the accuracy of your gesture recognition program developed in the last lesson. We do this by normalizing the hand landmarks distance matrix to a standard size. By doing this, you get accurate results independent of the distance your hand is from the camera. For your convenience, I include the code below which we develop in this lesson. Enjoy!

import time
import cv2
print(cv2.__version__)
import numpy as np

class mpHands:
    import mediapipe as mp
    def __init__(self,maxHands=2,tol1=.5,tol2=.5):
        self.hands=self.mp.solutions.hands.Hands(False,maxHands,tol1,tol2)
    def Marks(self,frame):
        myHands=[]
        frameRGB=cv2.cvtColor(frame,cv2.COLOR_BGR2RGB)
        results=self.hands.process(frameRGB)
        if results.multi_hand_landmarks != None:
            for handLandMarks in results.multi_hand_landmarks:
                myHand=[]
                for landMark in handLandMarks.landmark:
                    myHand.append((int(landMark.x*width),int(landMark.y*height)))
                myHands.append(myHand)
        return myHands
def findDistances(handData):
    distMatrix=np.zeros([len(handData),len(handData)],dtype='float')
    palmSize=((handData[0][0]-handData[9][0])**2+(handData[0][1]-handData[9][1])**2)**(1./2.)
    for row in range(0,len(handData)):
        for column in range(0,len(handData)):
            distMatrix[row][column]=(((handData[row][0]-handData[column][0])**2+(handData[row][1]-handData[column][1])**2)**(1./2.))/palmSize
    return distMatrix

def findError(gestureMatrix,unknownMatrix,keyPoints):
    error=0
    for row in keyPoints:
        for column in keyPoints:
            error=error+abs(gestureMatrix[row][column]-unknownMatrix[row][column])
    print(error)
    return error
def findGesture(unknownGesture,knownGestures,keyPoints,gestNames,tol):
    errorArray=[]
    for i in range(0,len(gestNames),1):
        error=findError(knownGestures[i],unknownGesture,keyPoints)
        errorArray.append(error)
    errorMin=errorArray[0]
    minIndex=0
    for i in range(0,len(errorArray),1):
        if errorArray[i]<errorMin:
            errorMin=errorArray[i]
            minIndex=i
    if errorMin<tol:
        gesture=gestNames[minIndex]
    if errorMin>=tol:
        gesture='Unknown'
    return gesture


width=1280
height=720
cam=cv2.VideoCapture(4,cv2.CAP_DSHOW)
cam.set(cv2.CAP_PROP_FRAME_WIDTH, width)
cam.set(cv2.CAP_PROP_FRAME_HEIGHT,height)
cam.set(cv2.CAP_PROP_FPS, 30)
cam.set(cv2.CAP_PROP_FOURCC,cv2.VideoWriter_fourcc(*'MJPG'))
findHands=mpHands(1)
time.sleep(5)
keyPoints=[0,4,5,9,13,17,8,12,16,20]
train=True
tol=10
trainCnt=0
knownGestures=[]

numGest=int(input('How Many Gestures Do You Want? '))

gestNames=[]

for i in range(0,numGest,1):
    prompt='Name of Gesture #'+str(i+1)+' '
    name=input(prompt)
    gestNames.append(name)
print(gestNames)

while True:
    ignore,  frame = cam.read()
    frame=cv2.resize(frame,(width,height))
    handData=findHands.Marks(frame)
    if train==True:
        if handData!=[]:
            print('Please Show Gesture ',gestNames[trainCnt],': Press t when Ready')
            if cv2.waitKey(1) & 0xff==ord('t'):
                knownGesture=findDistances(handData[0])
                knownGestures.append(knownGesture)
                trainCnt=trainCnt+1
                if trainCnt==numGest:
                    train=False
    if train == False:
        if handData!=[]:
            unknownGesture=findDistances(handData[0])
            myGesture=findGesture(unknownGesture,knownGestures,keyPoints,gestNames,tol)
            #error=findError(knownGesture,unknownGesture,keyPoints)
            cv2.putText(frame,myGesture,(100,175),cv2.FONT_HERSHEY_SIMPLEX,3,(255,0,0),8)
    for hand in handData:
        for ind in keyPoints:
            cv2.circle(frame,hand[ind],25,(255,0,255),3)
    cv2.imshow('my WEBcam', frame)
    cv2.moveWindow('my WEBcam',0,0)
    if cv2.waitKey(1) & 0xff ==ord('q'):
        break
cam.release()

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105

import time

import cv2

print(cv2.__version__)

import numpy as np

class mpHands:

import mediapipe as mp

def __init__(self,maxHands=2,tol1=.5,tol2=.5):

self.hands=self.mp.solutions.hands.Hands(False,maxHands,tol1,tol2)

def Marks(self,frame):

myHands=[]

frameRGB=cv2.cvtColor(frame,cv2.COLOR_BGR2RGB)

results=self.hands.process(frameRGB)

if results.multi_hand_landmarks != None:

for handLandMarks in results.multi_hand_landmarks:

myHand=[]

for landMark in handLandMarks.landmark:

myHand.append((int(landMark.x*width),int(landMark.y*height)))

myHands.append(myHand)

return myHands

def findDistances(handData):

distMatrix=np.zeros([len(handData),len(handData)],dtype='float')

palmSize=((handData[0][0]-handData[9][0])**2+(handData[0][1]-handData[9][1])**2)**(1./2.)

for row in range(0,len(handData)):

for column in range(0,len(handData)):

distMatrix[row][column]=(((handData[row][0]-handData[column][0])**2+(handData[row][1]-handData[column][1])**2)**(1./2.))/palmSize

return distMatrix

def findError(gestureMatrix,unknownMatrix,keyPoints):

error=0

for row in keyPoints:

for column in keyPoints:

error=error+abs(gestureMatrix[row][column]-unknownMatrix[row][column])

print(error)

return error

def findGesture(unknownGesture,knownGestures,keyPoints,gestNames,tol):

errorArray=[]

for i in range(0,len(gestNames),1):

error=findError(knownGestures[i],unknownGesture,keyPoints)

errorArray.append(error)

errorMin=errorArray[0]

minIndex=0

for i in range(0,len(errorArray),1):

if errorArray[i]<errorMin:

errorMin=errorArray[i]

minIndex=i

if errorMin<tol:

gesture=gestNames[minIndex]

if errorMin>=tol:

gesture='Unknown'

return gesture

width=1280

height=720

cam=cv2.VideoCapture(4,cv2.CAP_DSHOW)

cam.set(cv2.CAP_PROP_FRAME_WIDTH, width)

cam.set(cv2.CAP_PROP_FRAME_HEIGHT,height)

cam.set(cv2.CAP_PROP_FPS, 30)

cam.set(cv2.CAP_PROP_FOURCC,cv2.VideoWriter_fourcc(*'MJPG'))

findHands=mpHands(1)

time.sleep(5)

keyPoints=[0,4,5,9,13,17,8,12,16,20]

train=True

tol=10

trainCnt=0

knownGestures=[]

numGest=int(input('How Many Gestures Do You Want? '))

gestNames=[]

for i in range(0,numGest,1):

prompt='Name of Gesture #'+str(i+1)+' '

name=input(prompt)

gestNames.append(name)

print(gestNames)

while True:

ignore, frame = cam.read()

frame=cv2.resize(frame,(width,height))

handData=findHands.Marks(frame)

if train==True:

if handData!=[]:

print('Please Show Gesture ',gestNames[trainCnt],': Press t when Ready')

if cv2.waitKey(1) & 0xff==ord('t'):

knownGesture=findDistances(handData[0])

knownGestures.append(knownGesture)

trainCnt=trainCnt+1

if trainCnt==numGest:

train=False

if train == False:

if handData!=[]:

unknownGesture=findDistances(handData[0])

myGesture=findGesture(unknownGesture,knownGestures,keyPoints,gestNames,tol)

#error=findError(knownGesture,unknownGesture,keyPoints)

cv2.putText(frame,myGesture,(100,175),cv2.FONT_HERSHEY_SIMPLEX,3,(255,0,0),8)

for hand in handData:

for ind in keyPoints:

cv2.circle(frame,hand[ind],25,(255,0,255),3)

cv2.imshow('my WEBcam', frame)

cv2.moveWindow('my WEBcam',0,0)

if cv2.waitKey(1) & 0xff ==ord('q'):

break

cam.release()

s lesson. Enjoy!

Technology Tutorials

Tag Archives: Python

Sending Data Over WiFi Between Raspberry Pi Pico W and Your PC

Library for Reading a 16 Button Keypad on the Raspberry Pi

Using an Arduino with Python LESSON 14: Model a Moving Marble in a Room Using Parameters

Using an Arduino with Python LESSON 8: Live Thermometer 3D Visual Using DHT11

Improved Gesture Recognition in Python and MediaPipe

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