Week #6 - Journal 

The 6th-week assignment of the Maker Diploma is about making things get smart by using Arduino and code blocks that translate into Arduino C programming language to perform a specific command or function. The required is building and programming a smart circuit using an Arduino UNO to read a signal from an input component and control an action component using code blocks.

I looked for cool ideas to build the smart circuit and I found a tutorial on Arduino Project Hub about an "Ultrasonic Security System" to create a little security device using an Arduino. Since I'll be using an Ultrasonic sensor and a Piezo buzzer in my final project, I decided to proceed with this idea. 

I started by designing and simulating the smart circuit for the Ultrasonic security system using Tinkercad. My goal was to use an Arduino UNO board to control the input and output as follows: 

• Input: Ultrasonic sensor to measure the distance to an object using ultrasonic sound waves 

• Output: Piezo buzzer and red, yellow, and green LEDs to make a sound and emit light

Then, I started connecting my smart circuit and I used the following pins on the Arduino:

• 5V pin: on the Arduino to the positive channel of the breadboard

• GND pin: on the Arduino to the negative channel of the breadboard

• Pin 3: Echo Ultrasonic Sensor

• Pin 2: Trig Ultrasonic Sensor

• Pin 9: Buzzer

• Pin 4: Red LED

• Pin 5: Yellow LED

• Pin 6: Green LED

The wires connected to the LEDs are connected in line with the positive side of each LED, while the negative side of the LEDs is connected to the negative channel of the breadboard using 220Ω resistors. 

After that, I started working on the code blocks to build the code that would be uploaded to the Arduino board. The idea of the security system is that when the Ultrasonic sensor reads a distance from an object approaching, the following actions will happen:

• At 30 cm, the green LED will emit light

• At 20 cm, the yellow LED will emit light

• At 10 cm, the red LED will emit light and the buzzer will make an alarming sound.

Finally, I started the simulation to make sure the smart circuit was functional and I copied the code text to Arduino IDE to upload it to the Arduino board.

It took me a while to understand Arduino's different pins and how to use code blocks to program it. I faced an issue while working on the assignment related to the Piezo buzzer wiring and code. The tutorial that I followed from Arduino Project Hub wired the buzzer to pin 7 and was set to 1000. I couldn't figure out how to build code blocks for it, and there were several failed attempts. Then, I thought I should go back to the week's videos about the buzzer and I understood that a buzzer is an analog output. So I changed it to pin 9 and dragged the code block output set pin (9) to a value (1000). After that, it worked perfectly with the red LED.