Project | Technology Tutorials

In this video lesson we improve last weeks project by making the PyQt widget more virtual. The PyQt widget generates 3 sine waves, one for the Red color channel, one for the Green color channel, and one for the Blue color channel. The three sine waves are displayed on the widget. You are then given the opportunity in the widget to scale any of the three color channels. This allows you to calibrate your RGB LED in case any color channel is dominating. The widget also features a “Chase” mode where you can introduce phase injection into any of the color channels. This causes one or more of the color channels to “chase” the other ones. In this version, we preserve the phase as we turn the chase mode on or off. We also add buttons at the bottom of the widget to show the composite color being generated, as well as the individual R, G, and B color channels. This is the circuit schematic we are using on the Pi Pico side.

Circuit Schematic for Connecting the RGB LED

This is the code we developed to run on the Pi Pico side. It is the server side.

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")

You need to create this file, and save it as “secrets.py” in the lib folder of your raspberry pi Pico.

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

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

And finally, this is the client side program which 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 *
from PyQt5.QtGui 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)
chaseMode = False

phaseR=0
phaseG=2*np.pi/3
phaseB=4*np.pi/3

incR=0
incG=.5
incB=1

ampR=1
ampG=1
ampB=1

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 numPoints,xStart,xStop,Inc,frequency,phaseR,phaseG,phaseB,incR,incG,incB,ampR,ampG,ampB
    xStart=xStart + Inc
    xStop=xStop + Inc
    x =np.linspace(xStart, xStop , numPoints)
    if chaseMode:
        phaseR=(phaseR+incR*Inc)
        phaseG=(phaseG+incG*Inc)
        phaseB=(phaseB+incB*Inc)
    
    ySin=(255*np.sin(frequency*x+phaseR)/2+255/2)*ampR
    ySin2 = (255*np.sin(frequency*x + phaseG)/2+255/2)*ampG
    ySin3 = (255*np.sin(frequency*x + phaseB)/2+255/2)*ampB
    
    plotSin.setData(x, ySin)
    plotSin2.setData(x, ySin2)
    plotSin3.setData(x, ySin3)
    
    currentRed=int(ySin[numPoints-1])
    currentGreen=int(ySin2[numPoints-1])
    currentBlue=int(ySin3[numPoints-1])
    
    compositeColor=QColor(currentRed,currentGreen,currentBlue)
    compositeButton.setStyleSheet("background-color: "+compositeColor.name()+"; border-radius: 50px; min-width: 100px; min-height: 100px; font-size: 20px; color: white;")
    redButton.setStyleSheet("background-color: rgb("+str(currentRed)+ ",0,0); border-radius: 50px; min-width: 100px; min-height: 100px; font-size: 20px; color: white;")
    greenButton.setStyleSheet("background-color: rgb(0,"+str(currentGreen)+ ",0); border-radius: 50px; min-width: 100px; min-height: 100px; font-size: 20px; color: white;")
    blueButton.setStyleSheet("background-color: rgb(0,0,"+str(currentBlue)+ "); border-radius: 50px; min-width: 100px; min-height: 100px; font-size: 20px; color: white;")
    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 chaseMode
    if state:
        chaseMode=True
    if not state:
        chaseMode=False

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

def updateAmplitudeRed(value):
    global ampR
    ampR = value/100
    
def updateAmplitudeGreen(value):
    global ampG
    ampG = value/100
    
def updateAmplitudeBlue(value):
    global ampB
    ampB = value/100

for color,label in [['red','RED'],['green','GREEN'],['blue','BLUE']]:
    labelWidget=QLabel(label)
    labelWidget.setStyleSheet("color: "+color+";font-size:20px;")
    leftLayout.addWidget(labelWidget)
    
    slider=QSlider(Qt.Vertical)
    slider.setMinimum(0)
    slider.setMaximum(100)
    slider.setValue(100)
    slider.setStyleSheet("Qslider::handle:vertical{background-color: " + color+";}")
    
    if color=='red':
        slider.valueChanged.connect(updateAmplitudeRed)
    if color=='green':
        slider.valueChanged.connect(updateAmplitudeGreen)
    if color=='blue':
        slider.valueChanged.connect(updateAmplitudeBlue)
    
    leftLayout.addWidget(slider)

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

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

graphWidget =pg.PlotWidget()
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)
rightLayout.addWidget(graphWidget)

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

buttonLayout=QHBoxLayout()
compositeButton=QPushButton("RGB")
redButton=QPushButton("Red")
greenButton=QPushButton("Green")
blueButton=QPushButton("Blue")

for button in [compositeButton,redButton,greenButton,blueButton]:
    button.setFixedSize(100,100)
    buttonLayout.addWidget(button)

rightLayout.addLayout(buttonLayout)

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

mainLayout.addLayout(leftLayout)
mainLayout.addLayout(rightLayout)


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

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import sys

import socket

import numpy as np

import pyqtgraph as pg

from PyQt5.QtWidgets import *

from PyQt5.QtCore import *

from PyQt5.QtGui 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)

chaseMode = False

phaseR=0

phaseG=2*np.pi/3

phaseB=4*np.pi/3

incR=0

incG=.5

incB=1

ampR=1

ampG=1

ampB=1

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 numPoints,xStart,xStop,Inc,frequency,phaseR,phaseG,phaseB,incR,incG,incB,ampR,ampG,ampB

xStart=xStart + Inc

xStop=xStop + Inc

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

if chaseMode:

phaseR=(phaseR+incR*Inc)

phaseG=(phaseG+incG*Inc)

phaseB=(phaseB+incB*Inc)

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

ySin2 = (255*np.sin(frequency*x + phaseG)/2+255/2)*ampG

ySin3 = (255*np.sin(frequency*x + phaseB)/2+255/2)*ampB

plotSin.setData(x, ySin)

plotSin2.setData(x, ySin2)

plotSin3.setData(x, ySin3)

currentRed=int(ySin[numPoints-1])

currentGreen=int(ySin2[numPoints-1])

currentBlue=int(ySin3[numPoints-1])

compositeColor=QColor(currentRed,currentGreen,currentBlue)

compositeButton.setStyleSheet("background-color: "+compositeColor.name()+"; border-radius: 50px; min-width: 100px; min-height: 100px; font-size: 20px; color: white;")

redButton.setStyleSheet("background-color: rgb("+str(currentRed)+ ",0,0); border-radius: 50px; min-width: 100px; min-height: 100px; font-size: 20px; color: white;")

greenButton.setStyleSheet("background-color: rgb(0,"+str(currentGreen)+ ",0); border-radius: 50px; min-width: 100px; min-height: 100px; font-size: 20px; color: white;")

blueButton.setStyleSheet("background-color: rgb(0,0,"+str(currentBlue)+ "); border-radius: 50px; min-width: 100px; min-height: 100px; font-size: 20px; color: white;")

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 chaseMode

if state:

chaseMode=True

if not state:

chaseMode=False

app=QApplication(sys.argv)

window = QWidget()

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

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

mainLayout = QHBoxLayout(window)

leftLayout = QVBoxLayout()

rightLayout = QVBoxLayout()

def updateAmplitudeRed(value):

global ampR

ampR = value/100

def updateAmplitudeGreen(value):

global ampG

ampG = value/100

def updateAmplitudeBlue(value):

global ampB

ampB = value/100

for color,label in [['red','RED'],['green','GREEN'],['blue','BLUE']]:

labelWidget=QLabel(label)

labelWidget.setStyleSheet("color: "+color+";font-size:20px;")

leftLayout.addWidget(labelWidget)

slider=QSlider(Qt.Vertical)

slider.setMinimum(0)

slider.setMaximum(100)

slider.setValue(100)

slider.setStyleSheet("Qslider::handle:vertical{background-color: " + color+";}")

if color=='red':

slider.valueChanged.connect(updateAmplitudeRed)

if color=='green':

slider.valueChanged.connect(updateAmplitudeGreen)

if color=='blue':

slider.valueChanged.connect(updateAmplitudeBlue)

leftLayout.addWidget(slider)

sliderLabel=QLabel("Frequency: 1 Hz")

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

rightLayout.addWidget(sliderLabel)

slider = QSlider(Qt.Horizontal)

slider.setMinimum(1)

slider.setMaximum(40)

slider.setValue(10)

slider.valueChanged.connect(updateFrequency)

rightLayout.addWidget(slider)

graphWidget =pg.PlotWidget()

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)

rightLayout.addWidget(graphWidget)

toggleButton=QCheckBox("Chase Mode")

toggleButton.stateChanged.connect(toggleChase)

rightLayout.addWidget(toggleButton)

buttonLayout=QHBoxLayout()

compositeButton=QPushButton("RGB")

redButton=QPushButton("Red")

greenButton=QPushButton("Green")

blueButton=QPushButton("Blue")

for button in [compositeButton,redButton,greenButton,blueButton]:

button.setFixedSize(100,100)

buttonLayout.addWidget(button)

rightLayout.addLayout(buttonLayout)

timer = QTimer()

timer.timeout.connect(updatePlot)

timer.start(100)

mainLayout.addLayout(leftLayout)

mainLayout.addLayout(rightLayout)

window.setLayout(mainLayout)

window.show()

sys.exit(app.exec_())

In this video lesson we take you through the project of building an Arduino Barometric Pressure Weather Station. It builds on the last two lessons in this series. We measure and display instantaneous Barometric Pressure, normalized to Sea Level. Then in the lower portion on the OLED SSD1306 display, we show a graph of the barometric pressure over the last 24 hours.

Arduino Altimeter — Schematic for the Portable Arduino Barometric Pressure Sensor

Below we include the code we develop in the above video. Make sure to set the ‘alt’ variable to your elevation at your location, in meters.

#include <SPI.h>
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>
#include <Adafruit_BMP085.h>

int lastUpdate = 0;
int updateInterval = 600000;

float rawXdata[128];
int normXdata[128];

float rawYdata[128];
int normYdata[128];

float xMin = 0;
float xMax = 127;

float yMin = 28;
float yMax = 31;

float Pt = 14;
float Pb = 63;

float Pl = 0;
float Pr = 127;

int numPoints = 128;

Adafruit_BMP085 BP;
bool BMPconnected = false;

float BarPress = 30;
float BarPressNow = 30;
float alt = 1127;

int screenWidth = 128;
int screenHeight = 64;
int oledReset = -1;
#define SCREEN_ADDRESS 0x3C
Adafruit_SSD1306 oled(screenWidth, screenHeight, &Wire, oledReset);

void setup() {
  // put your setup code here, to run once:
  Serial.begin(9600);
  BMPconnected = BP.begin();
  if (BMPconnected == true) {
    Serial.println("BMP180 found and Connected");
  }
  if (BMPconnected == false) {
    Serial.println("BMP180 not found, Check Connections");
  }
  oled.begin(SSD1306_SWITCHCAPVCC, SCREEN_ADDRESS);
  oled.clearDisplay();
  oled.display();
  for (int i = 0; i < numPoints; i= i + 1) {
    rawXdata[i] = i;
  }
}

void loop() {
  // put your main code here, to run repeatedly:
  BarPressNow = normPress(alt);
  BarPress = .95 * BarPress + .05 * BarPressNow;
  if (millis() - lastUpdate >= updateInterval) {
    for (int i = 0; i < numPoints - 1; i = i + 1) {
      rawYdata[i] = rawYdata[i + 1];

    }
    lastUpdate=millis();
    rawYdata[numPoints-1]=BarPress;
    normData();
    oled.clearDisplay();
    plotGraph();
  }
  oled.clearDisplay();
  oled.setCursor(0, 0);
  oled.setTextColor(WHITE);
  oled.setTextSize(2);
  oled.print(BarPress);
  oled.setTextSize(1);
  oled.println(" In HG");
  normData();
  plotGraph();
  oled.display();
  delay(.1);
}

float normPress(float elev) {
  float BPRaw;
  float BPNorm;
  float T0 = 288.15;
  float L = .0065;
  float R = 8.3144598;
  float M = .0289644;
  float g = 9.8;
  float c = M * g / (R * L);
  BPRaw = BP.readPressure() * .0002953;
  BPNorm = BPRaw / pow(1 - L * elev / T0, c);
  return BPNorm;
}
void normData() {
  for (int i = 0; i < numPoints; i = i + 1) {
    normYdata[i] = (Pb - Pt) / (yMin - yMax) * (rawYdata[i] - yMax) + Pt;
    normXdata[i] = (Pr - Pl) / (xMax - xMin) * (rawXdata[i] - xMin) + Pl;
  }
}
void plotGraph() {
  oled.drawLine(Pl, Pt, Pl, Pb, WHITE);
  oled.drawLine(Pl, Pb, Pr, Pb, WHITE);
  int MID = (Pb - Pt) / (yMin - yMax) * (29.92 - yMax) + Pt;
  oled.drawLine(Pl, MID, Pr, MID, WHITE);
  for (int i = 0; i < numPoints - 1; i = i + 1) {
    oled.drawLine(normXdata[i], normYdata[i], normXdata[i + 1], normYdata[i + 1], WHITE);
  }
}

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#include <SPI.h>

#include <Wire.h>

#include <Adafruit_GFX.h>

#include <Adafruit_SSD1306.h>

#include <Adafruit_BMP085.h>

int lastUpdate = 0;

int updateInterval = 600000;

float rawXdata[128];

int normXdata[128];

float rawYdata[128];

int normYdata[128];

float xMin = 0;

float xMax = 127;

float yMin = 28;

float yMax = 31;

float Pt = 14;

float Pb = 63;

float Pl = 0;

float Pr = 127;

int numPoints = 128;

Adafruit_BMP085 BP;

bool BMPconnected = false;

float BarPress = 30;

float BarPressNow = 30;

float alt = 1127;

int screenWidth = 128;

int screenHeight = 64;

int oledReset = -1;

#define SCREEN_ADDRESS 0x3C

Adafruit_SSD1306 oled(screenWidth, screenHeight, &Wire, oledReset);

void setup() {

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

Serial.begin(9600);

BMPconnected = BP.begin();

if (BMPconnected == true) {

Serial.println("BMP180 found and Connected");

}

if (BMPconnected == false) {

Serial.println("BMP180 not found, Check Connections");

}

oled.begin(SSD1306_SWITCHCAPVCC, SCREEN_ADDRESS);

oled.clearDisplay();

oled.display();

for (int i = 0; i < numPoints; i= i + 1) {

rawXdata[i] = i;

}

void loop() {

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

BarPressNow = normPress(alt);

BarPress = .95 * BarPress + .05 * BarPressNow;

if (millis() - lastUpdate >= updateInterval) {

for (int i = 0; i < numPoints - 1; i = i + 1) {

rawYdata[i] = rawYdata[i + 1];

}

lastUpdate=millis();

rawYdata[numPoints-1]=BarPress;

normData();

oled.clearDisplay();

plotGraph();

}

oled.clearDisplay();

oled.setCursor(0, 0);

oled.setTextColor(WHITE);

oled.setTextSize(2);

oled.print(BarPress);

oled.setTextSize(1);

oled.println(" In HG");

normData();

plotGraph();

oled.display();

delay(.1);

}

float normPress(float elev) {

float BPRaw;

float BPNorm;

float T0 = 288.15;

float L = .0065;

float R = 8.3144598;

float M = .0289644;

float g = 9.8;

float c = M * g / (R * L);

BPRaw = BP.readPressure() * .0002953;

BPNorm = BPRaw / pow(1 - L * elev / T0, c);

return BPNorm;

}

void normData() {

for (int i = 0; i < numPoints; i = i + 1) {

normYdata[i] = (Pb - Pt) / (yMin - yMax) * (rawYdata[i] - yMax) + Pt;

normXdata[i] = (Pr - Pl) / (xMax - xMin) * (rawXdata[i] - xMin) + Pl;

}

void plotGraph() {

oled.drawLine(Pl, Pt, Pl, Pb, WHITE);

oled.drawLine(Pl, Pb, Pr, Pb, WHITE);

int MID = (Pb - Pt) / (yMin - yMax) * (29.92 - yMax) + Pt;

oled.drawLine(Pl, MID, Pr, MID, WHITE);

for (int i = 0; i < numPoints - 1; i = i + 1) {

oled.drawLine(normXdata[i], normYdata[i], normXdata[i + 1], normYdata[i + 1], WHITE);

}

Technology Tutorials

Tag Archives: Project

Improved PyQt Color Wheel Project

Portable Arduino Barometric Weather Station

Arduino Tutorial 24: Understanding Passive Buzzers

The Ultimate Raspberry Pi Project: To the Edge of Space with Raspberry Pi

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