Henry Varley – Page 3 – Henry's Website

IoT Temperature Meter

posted on 6 September 20216 September 2021

Parts

Description

In this project, I made an internet connected device which displays the temperature of the room it is situated in, and relays the temperature to the Blynk cloud service to be accessed from another device.

Gallery

Code

/*************************************************************
  Download latest Blynk library here:
    https://github.com/blynkkk/blynk-library/releases/latest

  Blynk is a platform with iOS and Android apps to control
  Arduino, Raspberry Pi and the likes over the Internet.
  You can easily build graphic interfaces for all your
  projects by simply dragging and dropping widgets.

    Downloads, docs, tutorials: http://www.blynk.cc
    Sketch generator:           http://examples.blynk.cc
    Blynk community:            http://community.blynk.cc
    Follow us:                  http://www.fb.com/blynkapp
                                Tweets by blynk_app

  Blynk library is licensed under MIT license
  This example code is in public domain.

 *************************************************************

  This example shows how to use ESP8266 Shield (with AT commands)
  to connect your project to Blynk.

  WARNING!
    It's very tricky to get it working. Please read this article:
    http://help.blynk.cc/hardware-and-libraries/arduino/esp8266-with-at-firmware

  Change WiFi ssid, pass, and Blynk auth token to run :)
  Feel free to apply it to any other example. It's simple!
 *************************************************************/

/* Comment this out to disable prints and save space */
#define BLYNK_PRINT Serial


/* Fill-in your Template ID (only if using Blynk.Cloud) */
#define BLYNK_TEMPLATE_ID "******************"
#define BLYNK_DEVICE_NAME "Temperature 1"
char auth[] = "**************************************";


#include &lt;ESP8266_Lib.h&gt;
#include &lt;BlynkSimpleShieldEsp8266.h&gt;


#include &lt;Wire.h&gt; // Enable this line if using Arduino Uno, Mega, etc.
#include &lt;DS18B20.h&gt;

#include "LCD.h" // For LCD
#include "LiquidCrystal_I2C.h" // Added library*

// You should get Auth Token in the Blynk App.
// Go to the Project Settings (nut icon).

// Your WiFi credentials.
// Set password to "" for open networks.
char ssid[] = "*************";  // Put WiFi SSID and Password here
char pass[] = "************";

// Hardware Serial on Mega, Leonardo, Micro...
#define EspSerial Serial1

// or Software Serial on Uno, Nano...
#include &lt;SoftwareSerial.h&gt;
SoftwareSerial EspSerial(2, 3); // RX, TX

// Your ESP8266 baud rate:
#define ESP8266_BAUD 9600

ESP8266 wifi(&amp;EspSerial);
DS18B20 ds(6);
LiquidCrystal_I2C lcd(0x27,2,1,0,4,5,6,7); // 0x27 is the default I2C bus address of the backpack-see article


void setup()
{
  // Debug console
  Serial.begin(9600);

  delay(10);

  // Set ESP8266 baud rate
  EspSerial.begin(ESP8266_BAUD);
  delay(10);

  lcd.begin (20,4); // 20 x 4 LCD module
  lcd.setCursor(6, 1);
  lcd.setBacklightPin(3,POSITIVE); // BL, BL_POL
  lcd.setBacklight(HIGH);

  Blynk.begin(auth, wifi, ssid, pass);
}

void loop()
{
  Blynk.run();

  float t = ds.getTempC();
  Serial.println(t);

  lcd.clear();
  lcd.setCursor(6, 1);`
  lcd.print(t);
  lcd.print("C");

  
  delay(2000);
  Blynk.virtualWrite(V10, t);
  
}
// Comment me plz

Mandelbrot Set Python

posted on 8 August 20218 August 2021tagged as Fractals, MandelbrotSet, Maths, Python

First let me get out the way the glaring problem of Python being a terrible language to make a Mandelbrot Set generator in. Mandelbrot Generators need speed to make the best possible images with the highest resolutions. Python, compared to a language such as C – which would be a much better language to program this project – is incredibly, incredibly slow to run. This is due to multiple things, mainly Python being an interpreted language meaning each line of code is compiled line as the program is executed, while a compiled language like C is converted into a binary file before runtime. The reason I used Python is because 1. I am a million times more competent with Python than any other programming language, and 2. Sufficient quality images can be acquired in Python in a relatively reasonable amount of time; good enough for this little experiment.

The Mandelbrot Set

The Mandelbrot Set is a set of numbers. A list of numbers which satisfy one rule. First, we must take the entire set of numbers, which in this case is a small area on the complex plain, with real numbers going along the x axis and imaginary numbers going up the y axis.

Complex numbers: the complex plane, addition and subtraction

If you throw a dart onto the complex plain, the position that dart landed can be described by taking it’s position on the x dimension and y dimension and combining them together, this is a complex number; a number combining a real part and an imaginary part.

A Mandelbrot Set generator takes every position in this plain (every complex number), with certain bounds and a set level of fidelity, and applies this formula to it.

$Z_{n+1} = Z_n^2 + c$

What this does is takes the number 0, square it, and add the current complex number to it. Then it does this again, but instead of Z being 0, Z is now the number which the last calculation created. This is repeated many times and this iteration will do one of two things. First, and true for basically all complex numbers save a few around 1 to 2 x or y on the plain the iteration will blow up as it is squared over and over again, so it will go off to infinity. However, due to the nature of mathematics, there are some numbers which do not spiral off into infinity, instead doing something far more remarkable. These numbers make a series of calculations which turn into a loop, they stabilise out into a repeated pattern of numbers that never expand to infinity. Complex numbers which do this are in the Mandelbrot Set.

So, if you repeat this process over and over again for many complex numbers you create a group of complex numbers which are in the set. But a list of numbers is not very interesting. The magic happens when you give the numbers a colour, most commonly black, and place them back onto the complex plain:

A fractal: a beautiful shape with infinite complexity buried in the reality of the universe.

In addition to simply colouring the numbers that are in the set black, pixels can also be coloured by taking the number of iterations it took the program before the complex number began to increase to infinity, essentially a measurement of how “stable” that position is.

By simply subtracting the red and green values of the pixel by the iteration count multiplied by some arbitrary constant to give it more of an effect, a blue colouration can be given to the space around the set: