Project description :
Transforming cheap rc toy to be AvoidanceBOT Arduino control.
Materials and ToolsMaterials
1. Arduino controller - Pro Mini 3.3V/5V
2. 2-LEDs (Different color)
3. 2-Resistor 1 kOhm. 1/4 watt.
4. Ultrasonic Distance Sensor Module (HC-SR04)
5. L298N dual motor drive module
6. Dupont wires.
7. PCB - DIY circuit board or prototype bread board.
8. Motor size 120
9. Motor size 180
10. Battery 5-9 V.
Tools
1. Soldering gun.
2. Soldering wire.
3. Soldering paste.
4. Screw driver.
5. Plier.
6. Hot glue gun.
7. Screw,Bolt & Nut.
Electronic devices installation & Wiring
Arduino Pro Mini pins to
2 : Green LED
Arduino Pro Mini pins to Ultrasonic Distance Sensor Module
3 : Trigger pin
4 : Echo pin
Arduino Pro Mini pins to L298N module
5 : ENA
6 : IN1
7 : IN2
8 : ENB
9 : IN3
10 : IN4
L298N module to :
OutputA : Steering motor
OutputB : Driving motor
+12V : Battery positive pole
GND : Connect Battery negative pole and Mini controller GND pin together.
+5V : Mini controller Vcc pin
* Don't use too small wire gauge,nevertheless controller pin will always HIGH status.
* Soldering need skill and extra cleanliness to prevent small electrical touching points.
Code sketch installation
Arduino sketch and Library :
1.Down load sketch file .ino and library zip file S05RF from Github.(This library file use with new ultrasonic sensor module HY-SRF05 but it can be applied to old model HC-SR04,they said it shall eliminate 0 noisy signal and better than older library(NewPing_v1.7).Add the library to your Arduino IDE.
2.Comply and upload .ino sketch to Arduino mini controller.(This sketch valid for Arduino UNO/Nano/Pro Mini 5V / 3.3V)
3.Open Arduino serial monitor to see output.
Observe ultrasonic sensor read distance value by varying different distance to detect.(This attached sketch read in centimeter unit.) If there are some 0 distance,it's normal.But If there are many continuous 0 distance,perhaps the ultrasonic sensor is defective.
4.Let's the robot test run by laying obstructive object around.Collect every problems for editing the sketch.
5.The speed of two motor can be adjusted to match the robot size,weight and battery power that you assembled by changing PWM value in command analogWrite(enableA, PWM) and analogWrite(enableB, PWM ); from 0 to 255.(in attached sketch is 150 for steering motor and 100 for driving motor)
To calibrate the robot speed,timing,appropriate distance zone and driving power is very difficult step.It needs time and experience to run the robot properly.
* Checking short circuit before connect power supply battery is necessary.
