Week #8 - Journal 

I used Tinkercad to design and simulate the smart circuit to make sure it was functional before being prototyped on an actual breadboard. After that, I used Arduino IDE to write and program Arduino C text code; then uploaded the code to the Arduino board. Finally, I used Arduino Bluetooth Control as a GUI on an Android phone to control the action components wirelessly.

To build the  smart circuit, I used the following components and materials:

• Breadboard

• Jumper Wires

• Arduino UNO

• Arduino USB Cable

• RGB LED 

• 220Ω Resistors

• Servo Motor

• HC-05 Bluetooth Module 

I started implementing and breadboarding the physical smart circuit with the Arduino board and components. I wired the components together following my Tinkercad design. I wired the Arduino 5V pin to the positive channel of the breadboard and the GND to the negative channel. Then, I wired the RGB LED to three 220Ω resistors, then to the Arduino (pin 3 green, pin 5 blue, pin 6 red), and the common cathode to the GND row on the breadboard. The servo motor was connected to Arduino's pin 9 and GND and 5V rows. Finally, I connected HC-05 Bluetooth Module to the GND and 5V rows on the breadboard, TX to Arduino's RX pin, and RX to Arduino's TX pin.

To build the code that would be uploaded to the Arduino board on Arduino IDE, I started with serial testing to make sure that the HC-05 Bluetooth Module was connected to the GUI on an Android phone (I used the Arduino Bluetooth Control app). Then, I installed the Servo.h library and used its example. I defined the Arduino pins of the servo motor and RGB LED.

After that, in the void setup that runs only once at the beginning, I used the servo example and set the function pinMode OUTPUT for the green, blue, and red pins. 

Next, in the void loop, which's a function that executes indefinitely until the power is off, I used the while (Serial.available () == 0) to disregard any unwanted values or singles. Then the following will happen:

• If incomingData received = 1: the RGB LED will emit green light and the servo motor will move 120°

• If incomingData received = 2: the RGB LED will emit blue light and the servo motor will move 90°

• If incomingData received = 3: the RGB LED will emit red light and the servo motor will move 30°

• Other than that (else) the RGB LED and servo motor will not perform any action.

Once I verified and was done with the code, I removed TX and RX pins wiring on the Arduino and connected the Arduino to my laptop to upload the code. Then, I rewired TX and RX pins again to the Arduino, opened the Arduino Bluetooth Control app on an Android phone, and connected the Bluetooth to the HC-05. It worked perfectly and was fully functional.

char incomingData = '0';

#include <Servo.h>

Servo servo_9;

#define Green 3

#define Blue 5

#define Red 6

void setup() {

 Serial.begin(9600);

 servo_9.attach(9, 500, 2500);

 pinMode(Green, OUTPUT);

 pinMode(Blue, OUTPUT);

 pinMode(Red, OUTPUT);

}

void loop() {

 while (Serial.available() == 0);

 incomingData = Serial.read();

 Serial.println(incomingData);

 if (incomingData == '1') {

   digitalWrite(Green, HIGH);

   digitalWrite(Blue, LOW);

   digitalWrite(Red, LOW);

   servo_9.write(120);

 } else if (incomingData == '2') {

   digitalWrite(Green, LOW);

   digitalWrite(Blue, HIGH);

   digitalWrite(Red, LOW);

   servo_9.write(90);

 } else if (incomingData == '3') {

   digitalWrite(Green, LOW);

   digitalWrite(Blue, LOW);

   digitalWrite(Red, HIGH);

   servo_9.write(30);

 } else {

   digitalWrite(Green, LOW);

   digitalWrite(Blue, LOW);

   digitalWrite(Red, LOW);

 }

}

I faced 2 issues while working on this assignment:

• In the function incomingData I wrote it with a capital D at the beginning, then incomingdata for the rest of the code. This issue kept me from verifying and uploading the code. I went back to the EOWeek Self-practice for week 8 and read through the codes there. I realized the issue, fixed it (changed all to incomingData), and it worked. 

• The second issue was connecting the Android phone Bluetooth to the HC-05 Bluetooth Module. In the videos of week 8, it was mentioned that I should find it under the name (HC-05), but there was nothing. I tried several times and restarted the phone. All I could find was the MD-BT-27 (as shown in the photo), but it had a password. With trial and error, I decided to write a random password (0000 or 1234). 1234 worked, the Bluetooth was connected, and the Arduino Bluetooth Control app worked perfectly.