Week 9

add an output device to a microcontroller board you've designed, and program it to do something

Firstly I satrted the week with redesigning my week 8 Electronics design week's board with lesser 0ohms.One because, it had too many 0 ohms and I didnt like it and secondly because it is no longer functionable after falling off a display shelf.And I successfully did with just 6 0 ohms this time!

But happily a board with lesser ohms:)

I fabricated it and finished soldering!

I tested the board to see if it was still working, I uploaded the button code

But for some weird reason, without even touching the buttons the led was lighting up when it sensed you were near.

but unfortunately when I was connecting the LCD to my board, I noticed I had no SCL pin my connector. And also when I was testing all the buttons, one of the buttons didn't work. So, I had to redesign it again.

No worries, I will get better each time!

I checked the ATtiny44 pinout again, and I found out that pin PA4 is SCL, so I changed it.

Since one of the switch was not working I changed it too. I connected the button in RX which was not recommended.The RX pin is designed for receiving serial data, not for reading button presses. It's optimized for this specific task and may not work reliably for other purposes like digital input from a button. Using it for such tasks can lead to unpredictable behavior and isn't recommended. It's better to use other available pins specifically designed for digital input tasks like reading button presses.

Now, the overall schematic and PCB design with the recent changes made

Programming a output device

Before starting the assignment, I decided to ask chatgpt to give me definitions on what voltage and curret are. And also the definitions of the components I use so that I could understand better.

Thank you Chatgpt for helping me understand and giving me simple definitions.

Voltage and Current

Voltage: Voltage is the electrical force or potential difference that pushes electric charges (electrons) through a circuit. It's measured in volts (V). Think of it like the "push" or pressure in a water pipe that makes water flow. Higher voltage means more force pushing the electrons.

Current: Current is the rate of flow of electric charge (electrons) through a conductor in a circuit. It's measured in amperes (A), often called amps. Current tells us how many electrons are flowing past a point in the circuit per second. You can compare it to the amount of water flowing through a pipe per second.

In summary, voltage is the electrical pressure that pushes electrons, while current is the actual flow of electrons through a conductor. Together, they determine how electricity behaves in a circuit.

LCD I2C display

What is a LCD?

An LCD (Liquid Crystal Display) is a flat panel display that uses liquid crystals to create images or text.An LCD display used in projects, such as those with Arduino or Raspberry Pi, typically refers to a small screen module that integrates liquid crystal technology for displaying text, numbers, or graphics. These displays come in various sizes and can be controlled via microcontroller platforms using specific libraries and protocols like I2C or SPI.

Thank you Chatgpt for helping me understand and giving me simple definitions.

What is a I2C module?

An I2C module is like a translator that helps electronic parts talk to each other using a special language called I2C. It's like a connector that allows different devices to communicate smoothly and share information.

Thank you Chatgpt for helping me understand and giving me simple definitions.

LCD I2C

To work with the LCD I2C, I needed to get an additional library because the standard Arduino IDE library doesn't support LCDs with I2C modules. It's like getting an extra tool to make sure the LCD and the I2C module can understand each other and work together properly.

For the additional library, you can download it from here Downloading the additional library Download the .zip file that the link above leads you to.

Arduino Example code, LCD I2C

/*
*	Hello_World.ino
*
*	Author: Frank Häfele
*	Date:	01.12.2023
*
*	Object: Print Hello World on LCD Display
*/

#include 


LCD_I2C lcd(0x27, 16, 2); // Default address of most PCF8574 modules, change according

void setup() {
    // If you are using more I2C devices using the Wire library use lcd.begin(false)
    // this stop the library(LCD-I2C) from calling Wire.begin()
    lcd.begin();
    lcd.display();
    lcd.backlight();
}

void loop()
{
    lcd.print("     Hello"); // You can make spaces using well... spaces
    lcd.setCursor(5, 1); // Or setting the cursor in the desired position.
    lcd.print("World!");
    delay(500);

    // Flashing the backlight
    for (int i = 0; i < 5; ++i)
    {
        lcd.backlight();
        delay(50);
        lcd.backlightOff();
        delay(50);
    }

    lcd.backlight();
    lcd.clear();
    delay(500);
}

                            

Since I am a beginner in using the LCD I2C I didnt understand the whole code. So I asked Chatgpt to explain it to me.

Explanation of Arduino Code: Hello World on LCD I2C

Here’s a breakdown of the Arduino code I used to display "Hello World!" on an LCD screen:

Setup

The code included the necessary library to communicate with the LCD using #include <LCD-I2C.h>.

The line LCD_I2C lcd(0x27, 16, 2); initializes the LCD object with the address and size of the display.

In the setup() function:

• lcd.begin(); initializes the LCD.
• lcd.display(); turns on the LCD display.
• lcd.backlight(); lights up the LCD backlight.

Loop

The loop() function runs continuously:

• lcd.print(" Hello"); prints "Hello" with leading spaces for formatting.
• lcd.setCursor(5, 1); sets the cursor at column 5, row 1.
• lcd.print("World!"); prints "World!" starting from the set cursor position.
• delay(500); pauses execution for half a second.
• A loop flashes the backlight five times for visual effect.
• lcd.clear(); clears the LCD screen.
• delay(500); pauses execution for another half second before repeating.

        lcd.print("     Hello");
        lcd.setCursor(5, 1);
        lcd.print("World!");
        delay(500);
            

lcd.print(" Hello"); prints "Hello" with leading spaces for formatting. This line demonstrates how to use spaces to align text on the LCD display.

lcd.setCursor(5, 1); sets the cursor at column 5, row 1 on the LCD display. This function allows you to position where the next text or character will be printed.

lcd.print("World!"); prints "World!" starting from the cursor position set by lcd.setCursor(5, 1);. This shows how to print text at a specific location on the LCD screen.

delay(500); pauses execution for half a second. It adds a delay before the LCD screen is cleared and the loop repeats.

Conclusion

This code continuously displays "Hello World!" on the LCD, with a flashing backlight effect every half-second. It's a basic example of using an Arduino with an LCD screen.

It worked!

Next, I just changed the text

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