Category Archives: Python

In this video lesson we show how Live Data can be plotted using a PyQt window. Our eventual goal is to bring in live data from the Raspberry Pi Pico W using UDP over WiFi, but to learn the concepts today, we will be generating a live sin wave to show how the plotting works. Here is the code we developed in this lesson:

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

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

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

count=0
incR=1
incG=2

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

def updatePlot():
    global numPoint,xStart,xStop,Inc,frequency,count
    xStart=xStart + Inc
    xStop=xStop + Inc
    x =np.linspace(xStart, xStop , numPoints)
    ySin=np.sin(frequency*x+count*incR/100*frequency)
    ySin2 = np.sin(frequency*x + 2*np.pi/3+count*incG/100*frequency)
    ySin3 = np.sin(frequency*x + 4*np.pi/3)
    
    plotSin.setData(x, ySin)
    plotSin2.setData(x, ySin2)
    plotSin3.setData(x, ySin3)
    
    count=count+1

def updateFrequency(value):
    global frequency, sliderLabel
    frequency = value/10
    sliderLabel.setText("Frequency: "+str(frequency)+" Hz")

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(-1.25,1.25)

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

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

import sys

import numpy as np

import pyqtgraph as pg

from PyQt5.QtWidgets import *

from PyQt5.QtCore import *

numPoints = 200

xStart = 0

xStop = 4*np.pi

frequency = 1

Inc = (2*np.pi/numPoints)

count=0

incR=1

incG=2

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

ySin=np.sin(frequency*x)

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

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

def updatePlot():

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

xStart=xStart + Inc

xStop=xStop + Inc

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

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

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

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

plotSin.setData(x, ySin)

plotSin2.setData(x, ySin2)

plotSin3.setData(x, ySin3)

count=count+1

def updateFrequency(value):

global frequency, sliderLabel

frequency = value/10

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

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(-1.25,1.25)

timer = QTimer()

timer.timeout.connect(updatePlot)

timer.start(100)

window.setLayout(layout)

window.show()

sys.exit(app.exec_())

Python

PyQt Essentials for Absolute Beginners

March 4, 2025 admin

In this Video Lesson we show you how to create a Graphical User Interface to allow you to interact with your python program and hardware projects. The GUI can have buttons, slider bars, radio buttons, drop down menus, and many more widgets. In this lesson we show you how to install the package, and step-by-step instructions on how to use it. For your convenience, here is the code we developed in the lesson.

import sys
from PyQt5.QtWidgets import *
from PyQt5.QtCore import Qt
import time

def greenButtonPressed():
    print("green button clicked")
def yellowButtonPressed():
    print("yellow button clicked")
def redButtonPressed():
    print("red button clicked")
def offButtonPressed():
    print("off button clicked")
def sliderValueChanged(val):
    frequency=val/10
    sliderLabel.setText("Frequency: "+str(frequency)+" Hz")
    print("Frequency: ",frequency)

app = QApplication(sys.argv)
window = QWidget()
window.setWindowTitle("My Grand Widget")
window.setGeometry(100,100,800,600)

widgetBox=QVBoxLayout(window)
buttonBox=QHBoxLayout()

greenButton = QPushButton("Green Button")
greenButton.setStyleSheet("background-color: green; color: white;")
greenButton.clicked.connect(greenButtonPressed)
buttonBox.addWidget(greenButton)

yellowButton = QPushButton("Yellow Button")
yellowButton.setStyleSheet("background-color: yellow; color: black;")
yellowButton.clicked.connect(yellowButtonPressed)
buttonBox.addWidget(yellowButton)

redButton = QPushButton("Red Button")
redButton.setStyleSheet("background-color: red; color: white;")
redButton.clicked.connect(redButtonPressed)
buttonBox.addWidget(redButton)

offButton = QPushButton("Off Button")
offButton.setStyleSheet("background-color: black; color: white;")
offButton.clicked.connect(offButtonPressed)

slider = QSlider(Qt.Horizontal)
slider.setMinimum(1)
slider.setMaximum(40)
slider.setValue(10)
slider.setTickPosition(QSlider.TicksBelow)
slider.setTickInterval(5)
slider.valueChanged.connect(sliderValueChanged)


sliderLabel=QLabel("Frequency: 1.0 HZ")
sliderLabel.setAlignment(Qt.AlignCenter)
sliderLabel.setStyleSheet("font-size: 24px;padding 2px;")

widgetBox.addLayout(buttonBox)
widgetBox.addWidget(sliderLabel)
widgetBox.addWidget(slider)
widgetBox.addStretch()

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

import sys

from PyQt5.QtWidgets import *

from PyQt5.QtCore import Qt

import time

def greenButtonPressed():

print("green button clicked")

def yellowButtonPressed():

print("yellow button clicked")

def redButtonPressed():

print("red button clicked")

def offButtonPressed():

print("off button clicked")

def sliderValueChanged(val):

frequency=val/10

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

print("Frequency: ",frequency)

app = QApplication(sys.argv)

window = QWidget()

window.setWindowTitle("My Grand Widget")

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

widgetBox=QVBoxLayout(window)

buttonBox=QHBoxLayout()

greenButton = QPushButton("Green Button")

greenButton.setStyleSheet("background-color: green; color: white;")

greenButton.clicked.connect(greenButtonPressed)

buttonBox.addWidget(greenButton)

yellowButton = QPushButton("Yellow Button")

yellowButton.setStyleSheet("background-color: yellow; color: black;")

yellowButton.clicked.connect(yellowButtonPressed)

buttonBox.addWidget(yellowButton)

redButton = QPushButton("Red Button")

redButton.setStyleSheet("background-color: red; color: white;")

redButton.clicked.connect(redButtonPressed)

buttonBox.addWidget(redButton)

offButton = QPushButton("Off Button")

offButton.setStyleSheet("background-color: black; color: white;")

offButton.clicked.connect(offButtonPressed)

slider = QSlider(Qt.Horizontal)

slider.setMinimum(1)

slider.setMaximum(40)

slider.setValue(10)

slider.setTickPosition(QSlider.TicksBelow)

slider.setTickInterval(5)

slider.valueChanged.connect(sliderValueChanged)

sliderLabel=QLabel("Frequency: 1.0 HZ")

sliderLabel.setAlignment(Qt.AlignCenter)

sliderLabel.setStyleSheet("font-size: 24px;padding 2px;")

widgetBox.addLayout(buttonBox)

widgetBox.addWidget(sliderLabel)

widgetBox.addWidget(slider)

widgetBox.addStretch()

window.setLayout(widgetBox)

window.show()

sys.exit(app.exec_())

Python, Raspberry Pi Pico

Simple Client Server Project for the Raspberry Pi Pico W

February 25, 2025 admin

In this video lesson we demonstrate a simple client server project on the Raspberry Pi Pico W. The Pico is configures as the server, and your desktop pc or laptop is configures to be the client. You will be running python on your PC. The project requests the user on the PC to specify a desired color. The color is then sent to the Pico, the Server.

For this lesson we are not using the breadvolt power supply, but we will use it in future lessons. For this lesson, you do not need to attach it, and if you do attach it, leave it ‘off’.

Below is the schematic for the Server Side of the project:

LED and Buttons — Schematic for Circuit to Demonstrate a Client Server Example on Pi Pico

For your convenience, this is the code we developed in the video

import network
import usocket as socket
import secrets
import time

greenLED=machine.Pin(18,machine.Pin.OUT)
yellowLED=machine.Pin(19,machine.Pin.OUT)
redLED=machine.Pin(20,machine.Pin.OUT)
# 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
    color, client_address = server_socket.recvfrom(1024)
    color=color.decode()
    print("Client Request:",color)
    print("FROM CLIENT",client_address)
    
    if (color=="green"):
        greenLED.on()
        yellowLED.off()
        redLED.off()
    if (color=="yellow"):
        greenLED.off()
        yellowLED.on()
        redLED.off()
    if (color=="red"):
        greenLED.off()
        yellowLED.off()
        redLED.on()
    if (color=="off"):
        greenLED.off()
        yellowLED.off()
        redLED.off()
    
    # Send data to client
    data="LED "+color+" executed"
    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

greenLED=machine.Pin(18,machine.Pin.OUT)

yellowLED=machine.Pin(19,machine.Pin.OUT)

redLED=machine.Pin(20,machine.Pin.OUT)

# 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

color, client_address = server_socket.recvfrom(1024)

color=color.decode()

print("Client Request:",color)

print("FROM CLIENT",client_address)

if (color=="green"):

greenLED.on()

yellowLED.off()

redLED.off()

if (color=="yellow"):

greenLED.off()

yellowLED.on()

redLED.off()

if (color=="red"):

greenLED.off()

yellowLED.off()

redLED.on()

if (color=="off"):

greenLED.off()

yellowLED.off()

redLED.off()

# Send data to client

data="LED "+color+" executed"

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)

Remember you must create a secrets.py file, and save it on the Pi Pico in the lib folder. You need to specify YOUR WiFi name and password in the file.

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

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

And finally, here is the code to run on the client side on your PC

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
    myColor=input("Please Input Your Color (Green, Yellow, Red, Off )")
    myColor=myColor.lower()
    client_socket.sendto(myColor.encode(), server_address)
    
    # Receive data from the server
    data, addr = client_socket.recvfrom(1024)
    print('Received data:', data.decode())

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

myColor=input("Please Input Your Color (Green, Yellow, Red, Off )")

myColor=myColor.lower()

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

# Receive data from the server

data, addr = client_socket.recvfrom(1024)

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

Python, Raspberry Pi Pico

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

February 18, 2025 admin

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 Pico

Raspberry Pi Pico PIO State Machine IRQ Interrupts

January 7, 2025 admin

<span data-mce-type="bookmark" style="display: inline-block; width: 0px; overflow: hidden; line-height: 0;" class="mce_SELRES_start"></span> In the video lesson above, we show how to incorporate IRQ interrupts on the Pi Pico PIO State Machines. The state machines will monitor the buttons, watching for button presses. When a button is pressed, an interrupt is set. That interrupt can then be used by that same state machine, a different state machine on the same PIO, or in the main micropython program. Our first example will be to toggle the LED in the main python program, based on the interrupt from the state machine. In the second example, one state machine monitors the button, and the second state machine controls the LED. This is a schematic for the circuit we will be using.

Circuit Schematic for Button Control LED Interrupts

This first code controls the LED from the main python program.

import rp2
from machine import Pin
import time

# Define PIO program for SM0 to trigger an interrupt on button press
@rp2.asm_pio()
def button_irq():
    wrap_target()
    wait(1, pin, 0)  [31]  # Wait for the button press (low signal on GPIO 11)
    nop() [31]
    nop() [31]
    nop() [31]
    nop() [31]
    irq(block, 0)      # Trigger interrupt 0
    wait(0, pin, 0)    # Wait for the button release (high signal on GPIO 11)
    nop() [31]
    nop() [31]
    nop() [31]
    nop() [31]
    wrap()
# Initialize State Machine 0 for the button (GPIO 11)
button_pin = Pin(11, Pin.IN, Pin.PULL_DOWN)
sm_button = rp2.StateMachine(0, button_irq, freq=2000, in_base=button_pin)
# GPIO pin for the LED (GPIO 18)
led_pin = Pin(18, Pin.OUT)
# Interrupt handler for the button press
def button_handler(sm):
    led_pin.value(not led_pin.value())  # Toggle LED state
# Attach the interrupt handler to the State Machine's IRQ
sm_button.irq(button_handler)
# Activate the state machine
sm_button.active(1)

# Keep the program running
while True:
    time.sleep(1)

import rp2

from machine import Pin

import time

# Define PIO program for SM0 to trigger an interrupt on button press

@rp2.asm_pio()

def button_irq():

wrap_target()

wait(1, pin, 0) [31] # Wait for the button press (low signal on GPIO 11)

nop() [31]

irq(block, 0) # Trigger interrupt 0

wait(0, pin, 0) # Wait for the button release (high signal on GPIO 11)

nop() [31]

wrap()

# Initialize State Machine 0 for the button (GPIO 11)

button_pin = Pin(11, Pin.IN, Pin.PULL_DOWN)

sm_button = rp2.StateMachine(0, button_irq, freq=2000, in_base=button_pin)

# GPIO pin for the LED (GPIO 18)

led_pin = Pin(18, Pin.OUT)

# Interrupt handler for the button press

def button_handler(sm):

led_pin.value(not led_pin.value()) # Toggle LED state

# Attach the interrupt handler to the State Machine's IRQ

sm_button.irq(button_handler)

# Activate the state machine

sm_button.active(1)

# Keep the program running

while True:

time.sleep(1)

This next program uses only the state machines. Interrupts and LED control are both done in the state machines.

import rp2
from machine import Pin
import time

@rp2.asm_pio()
def button_irq():
    wrap_target()
    wait(1, pin, 0) [31]
    nop() [31]
    nop() [31]
    nop() [31]
    nop() [31]
    irq(block,0)
    wait(0,pin,0)
    nop() [31]
    nop() [31]
    nop() [31]
    nop() [31]
    wrap()

@rp2.asm_pio(out_init=rp2.PIO.OUT_LOW)
def led_control():
    set(x,0b00000)
    wrap_target()
    wait(1, irq, 0)
    mov(x,invert(x))
    mov(pins,x)
    irq(clear, 0)
    wrap()

button_pin = Pin(11,Pin.IN,Pin.PULL_DOWN)
sm_button=rp2.StateMachine(0,button_irq, freq=2000, in_base=button_pin)

led_pin = Pin(18, Pin.OUT)
sm_led=rp2.StateMachine(1, led_control, freq=2000, out_base=led_pin)
sm_button.active(1)
sm_led.active(1)

import rp2

from machine import Pin

import time

@rp2.asm_pio()

def button_irq():

wrap_target()

wait(1, pin, 0) [31]

nop() [31]

irq(block,0)

wait(0,pin,0)

nop() [31]

wrap()

@rp2.asm_pio(out_init=rp2.PIO.OUT_LOW)

def led_control():

set(x,0b00000)

wrap_target()

wait(1, irq, 0)

mov(x,invert(x))

mov(pins,x)

irq(clear, 0)

wrap()

button_pin = Pin(11,Pin.IN,Pin.PULL_DOWN)

sm_button=rp2.StateMachine(0,button_irq, freq=2000, in_base=button_pin)

led_pin = Pin(18, Pin.OUT)

sm_led=rp2.StateMachine(1, led_control, freq=2000, out_base=led_pin)

sm_button.active(1)

sm_led.active(1)

Technology Tutorials

Category Archives: Python

Plotting Live Data in Python Using PyQT

PyQt Essentials for Absolute Beginners

Simple Client Server Project for the Raspberry Pi Pico W

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

Raspberry Pi Pico PIO State Machine IRQ Interrupts

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