Tag Archives: Plotting

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_())

Arduino

Plot any Data or Graph on any OLED

March 6, 2025 admin

In this video I show you how you can easily plot any graph or data onto any OLED display. We create a mathematical function which will map the raw data onto the screen. We demonstrate the function with a sin wave, but the function will work with any equation or data. This is the code which we developed in the video.

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

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

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

float xMin = 0;
float xMax = 2 * 3.1415;

float yMin = -1;
float yMax = 1;

float Pt = 0;
float Pb = 63;

float Pl = 0;
float Pr = 127;

float pi = 3.14159265;

int numPoints = 128;

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

int j=0;

void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  oled.begin(SSD1306_SWITCHCAPVCC, SCREEN_ADDRESS);
  oled.clearDisplay();
  oled.display();
}
void loop() {
  // put your main code here, to run repeatedly:

  for (int i = 0; i < numPoints; i = i + 1) {
    rawXdata[i] = i * (2 * pi / 127);
    rawYdata[i] = sin(rawXdata[i]);
    Serial.println(rawYdata[i]);
    delay(100);
  }
normData();
plotGraph();
oled.display();
}

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);
  for (int i=0;i<numPoints-1;i=i+1){
  oled.drawLine(normXdata[i],normYdata[i],normXdata[i+1],normYdata[i+1],WHITE);
  }
}

#include <SPI.h>

#include <Wire.h>

#include <Adafruit_GFX.h>

#include <Adafruit_SSD1306.h>

float rawXdata[128];

int normXdata[128];

float rawYdata[128];

int normYdata[128];

float xMin = 0;

float xMax = 2 * 3.1415;

float yMin = -1;

float yMax = 1;

float Pt = 0;

float Pb = 63;

float Pl = 0;

float Pr = 127;

float pi = 3.14159265;

int numPoints = 128;

int screenWidth = 128;

int screenHeight = 64;

int oledReset = -1;

#define SCREEN_ADDRESS 0x3C

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

int j=0;

void setup() {

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

Serial.begin(115200);

oled.begin(SSD1306_SWITCHCAPVCC, SCREEN_ADDRESS);

oled.clearDisplay();

oled.display();

}

void loop() {

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

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

rawXdata[i] = i * (2 * pi / 127);

rawYdata[i] = sin(rawXdata[i]);

Serial.println(rawYdata[i]);

delay(100);

}

normData();

plotGraph();

oled.display();

}

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);

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

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

}

Arduino, Arduino 9-Axis IMU Totorials, Tutorial

9-Axis IMU LESSON 4: Plotting Serial Data from Arduino with Control of Axis Scale

September 5, 2019 admin

As this project continues it is very important for us to be able to quickly and easily plot data streaming from the sensor. The Arduino Serial Plotter has some real limitations, we recommend a simple “Serial Plotter” tool that can be downloaded. In this video we take you step by step through the download and installation process, and then an overview of how to use the tool.

Technology Tutorials

Tag Archives: Plotting

Plotting Live Data in Python Using PyQT

Plot any Data or Graph on any OLED

9-Axis IMU LESSON 4: Plotting Serial Data from Arduino with Control of Axis Scale

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