Introduction: Smart Compass

About: Technomentis is a venture to foster innovation and hands on learning for youngsters at formative ages. We explore, create, design, tinker and innovate at Explorato - our makers space.

Artists have often found difficulties in drawing an arc or a circle with precision on sheets of different sizes. The smart compass is a simple mobile app based utility device that can draw arcs with different radii. The usage of servo motor in this project contributes to the accurate movement of the end effector (pen/pencil). The compass is designed to rotate to a certain degree specified by the user in the Mobile App via Bluetooth. Furthermore, a provision for drawing with three different radii is provided.

Step 1: Components Required:

  1. Intel Galileo Board x 1
  2. Power Cord x 1
  3. USB cable x 1
  4. Servo Motor x 1
  5. HC-05 Bluetooth Module x 1
  6. Breadboard x 1
  7. Connecting Wires (Male to Male) x 20
  8. Connecting Wires (Male to Female) x 20

Step 2: Interfacing Bluetooth With Intel Galileo

HC-05 Bluetooth Module

It is a wireless communication module that transmits data serially. Out of the six pins that comes with general break out board, only 4 pins are used. VCC pin of HC-05 is connected to +5V while GND pin is connected to GND of the microcontroller. RX pin refers to receiver and TX pin refers to transmitter. These pins are used for communication between the Bluetooth and the microcontroller.
Note: HC-06 Bluetooth modules can also be used for this project instead of HC-05.

Circuit Connections:

  1. Place the HC-05 on the Breadboard.
  2. Connect an M-M jumper wire from the 5V pin of the Intel Galileo to the vertical column where VCC of HC-05 is placed.
  3. Connect an M-M jumper wire from the GND pin of the HC-05 to the GND pin of Intel Galileo.
  4. Connect an M-M jumper wire from the TX pin of the HC-05 to pin 0 of the Intel Galileo.
  5. Connect an M-M jumper wire from the RX pin of the HC-05 to pin 1 of the Intel Galileo.

Step 3: Interfacing Servo Motor With Intel Galileo

Servo Motor:

A servo motor is a rotary actuator that allows for precise control of angular position. It consists of a motor coupled to a sensor for position feedback. By varying the pulse width of the output voltage to a servo, you can move a servo to a specific position.

Circuit Connections:

  1. The Orange wire of the Servo Motor is the signal Wire which will be connected to Digital PWM Pin 3 on the Intel Galileo.
  2. The Brown wire of the Servo Motor is the GND wire will be connected to the breadboard where GND from Intel Galileo is connected.
  3. The Red wire of the Servo Motor is the VCC wire and it will be connected to the breadboard where 5V of the Intel Galileo is connected.

The connections of the Servo Motor will be done using Male to Male connecting wire.

Step 4: Download and the Upload the Sketch

Step 5: Download and Install Android App

Download and install the following Android App and follow the instructions

  1. Open the Bluetooth Settings and pair your phone with HC-05. (Passcode is '1234')
  2. Open the App.
  3. Tap the 'Connect' button and choose 'HC-05'. Now, it, should show as 'Connected'.

Now, you can control the curtain from your phone!

Step 6: Reference Images for Construction