Piotr Bejenka Fab Academy 2020 Week 11

Invidal Assignment

For this assigment I will start with building a circut with LCM1602 LCD 16x2 screen.

Normally connectin such screen is complicated and requires some additional components like potentiometer and resissotrs. To make the connecting easier and less messy I used LCD screen with I2C conventer soldered.

Building a connection with such conventer is simple.
To visualise how the connection will look like I used website https://www.circuito.io.

The real-life circut looks as following:

So now I have to write the code to use it 1st. But before I start writing I need to download proper library to properly use the screen. I decided to use New LiquidCrystal .
To install the library I need to place it in general folder of Arduino Libraries C:/Users/Me/Documents/Arduino/Libraries/.
Now I can take a look at LiquidCrystal_I2C.h as it is a file that I will include into my sketch. Reading that library file will give me important informations about using in at its full potential.
Lets start code writing. I asked the professional for aid.

After 15-20 minutes the code looks as following:

	#include    // standard lib for Arduino projects like this
	#include  // lib for I2C for LCD that I downloaded and installed into arduino library
	LiquidCrystal_I2C lcd(0x27, 2, 1, 0, 4, 5, 6, 7, 3, POSITIVE);  // Setting an address of I2C for 0x27

	void setup() {
	  lcd.begin(16,2);   // Iinicialisation of LCD 2x16
	  lcd.backlight(); // Turning on the backlight of the screen
	  lcd.setCursor(0,0); // Seting a position for cursors on 1st top line, which is basically a place where it will start writing the text
	  lcd.print("Hi Fabacademy!"); // Writing text on screen
	  delay(500);
	  lcd.setCursor(0,1); // Seting cursors on second line
	  lcd.print("2020"); // Writing text on screen
	}

	void loop() {
	// nothing here cuz it is just a test
	}

After I uploaded the code into the board nothing happened... or rather this happened:

To find the solution of the problem I decided to make a list of the possible bugs:

Code
Connection
Arduino itself
Connection wires

Then I evaluated those possible bugs and decided to start from easy ones so:
For 1st try was the connection, I checked online datasheets for the LCM1602 module with i2c conventer and it turned out to be OK.
As 2nd I decided to check on new arduino but problem remained.
3rd try goes to connection wires, I made simple LED circut to test if the wires are OK and test came out possitive for all wires.
As a 4th and last try I checked again very slowly the code. It looked OK.
I have spend few hours looking and diging for the problem.
After this time I realised that I might have wrong I2C address. To check this I found on Arduino website a code that checks the connected I2C device address.
I2C Scanner

Using this I2C Scanner worked perfectly after a second I knew the proper address for my i2c conventer.

After I changed the line that is responsible for I2C address:
Before: LiquidCrystal_I2C lcd(0x27, 2, 1, 0, 4, 5, 6, 7, 3, POSITIVE);
After: LiquidCrystal_I2C lcd(0x20, 2, 1, 0, 4, 5, 6, 7, 3, POSITIVE);
I uploaded the code again and the effect was as it was expected to be:

Adding DHT11 Sensor

To make the circut more intresting I decided to add a DHT11 sensor to make a readout of temperature and humidity visible on the LCD screen. I will use knowledge from the Input Devices week and use the scheme of the circut. I will also add a button to the circut.
The circut will work in following scheme:
1. The setup will print "%RH" and "*C" on screen in two separte lines.
2. The void loop will wait for user to the button.
3. After the button is pressed the DHT11 sensor will make a readout.
4. The readout will be added to the coresponding lines on the screen.
To make the code I merged the code from before with the code from week 09 and also added button state check feature. So the code looks as following:

#include "DHT.h" //Including the sensor library
#include    // standard lib for Arduino projects like this
#include  // lib for I2C for LCD that I downloaded and installed into arduino library
#define DHT11_PIN 6 // defining the physical sensor - telling the board on which PIN the sensor data in supplied
DHT dht; // declaration needed for DHT library
const int buttonPin = 3; //Pin for the button
LiquidCrystal_I2C lcd(0x20, 2, 1, 0, 4, 5, 6, 7, 3, POSITIVE);  // Setting an address of I2C for 0x20

void setup() //setup void in which we state things that we want to declare once for whole code operation like pins etc.
{
  pinMode(buttonPin, INPUT); //setting the input PIN
  Serial.begin(9600); // declaration of badurate need to communicate with board on serial monitor
  dht.setup(DHT11_PIN); // declaration of type of the sensor applied for library purpose
  lcd.begin(16,2);   // Inicialisation of LCD 2x16
  lcd.backlight(); // Turning the screen backligh on
  lcd.setCursor(0,0); // Seting a position for cursors on 1st top line, which is basically a place where it will start writing the text
  lcd.print("%RH="); // Printing on the screen
  delay(500);
  lcd.setCursor(0,1); // Setting the cursor on 2nd line
	lcd.print("*C"); // Printing on the screen
}

void loop() // loop void is a section that is repeated continuously
{
    if (digitalRead(buttonPin) == HIGH) //checking the state of the button
    {
  int humm = dht.getHumidity(); // using command supplied by library to read value of humidity and signing it into a int valuable
  lcd.setCursor(4,0);
  lcd.print(humm);
  int temp = dht.getTemperature(); // using command supplied by library to read value of temperature and signing it into a int valuable
  lcd.setCursor(3,1);
  lcd.print(temp);
  delay(1000);
       }
  delay(500);
}

Operation of the circut:

Week 11:Output Devices

Invidal Assignment

Adding DHT11 Sensor

Group Assignment

LCD Screen Test

Servo Test