This Instructable made by Sara Casasola Borrego and Óscar Elena Varela details how to create a remote controlled car using a ATmega328P microcontroller (this one is the microcontroller used by Arduino) and communication by Bluetooth.This project was for 'Creative Electronics', a Beng Electronics Engineering 4th year module at the University of Málaga, School of Telecommunications. ( http://www.etsit.uma.es/ )
The design is such that the car can be directed to the place that we want in the moment that we desire, also, it has a light system which can be understood like high beams, low beams and reversing lights that it could be turned on or turned off. All of this can be controlled by Android, meaning, by Smartphone or tablet.
The tools that we are going to use are the next:
· Microcontroller ATMega328P
· Arduino LaunchPad
· Servo Futaba S3003
· Servo Socket
· Bluetooth Module for Arduino HC-06
· Bluetooth Socket
· Voltage Regulator LM2596S
· Quartz Crystal
· H Bridge: BD243 Transistors; TIP32C Transistors; 2N2222 Transistors
· LDR Resistor
· Perforated Sheet
· Car Chassis
· DC Motors
Step 1: Components Interconnected
In the picture that we can see up, there is a block diagram with the different components of the design interconnected between them.
Step 2: H Bridge
The H Bridge is necessary because it is what allows a motor to run forwards/backwards. To create this device we have used two BD243 transistors, two TIP32C transistors and two 2N2222 transistors besides two 1kΩ and two 27Ω resistors. This components were interconnected like the diagram shows above.
The sheet finished is like the picture where black and red wires are the points 'a' and 'b' of the motor in the previous diagram and the different signals are marked.
Step 3: Voltage Regulator
We have used a LM2596S Voltage Regulator with the schematic above.
We could find a PCB which we could buy. This module should be regulated for the 5V voltage in which the circuit worked. For this it uses a potenciometer.
Step 4: Bluetooth Module HC-06
This device implements a Virtual UART in which like master has a bidirectional communication with the microcontroller.
Step 5: Servo
We are used a S3003 servo. This one is used for the steering and it is connected to the 15 pin of the microcontroller.
Step 6: Light System
We have incorporated a Light System that lies in a detector and a actuator.
The detector consists of a LDR with a pull-down resistor that when the light level is less than a threshold turns on a LED considers like low beams of the car.
The actuator consists of three kind of LEDs. One of them lights up itself with the maximum power and plays the role of the high beam. The second one is such that we can control it in two ways, one of them is previously commented and it is with the detector, the second one is like the first kind of LED, just with one port of the microcontroller although without the maximum power. Finally, the last one is the reverse light and it turns on when the car moves backwards.
Step 7: Code
This is the code for Arduino.
Step 8: App
We have used an application called MOBOT BTCar (avaliable in Play Store). This app sends different kinds of commands by Bluetooth depending on the movements of the car or the ligth chosen. With the purpose that we can use the code mentioned before we need to introduce the same movements codes in the application.