Arduino code

The code that brings Rambo to life!

Initialisation

Assigning the different variables and pins of the arduino.










Driving

This part regulates the voltage to the H-bridge controller, it also reads the values of the encoders to regulate the motors such that both turn at the same speed. For this the angle difference between the two motors is used, if they have the same angle it is assumed they drive at the same speed.



Stopping

This function stops the motors.

Turning

When the robot detects an edge of the table, this function makes the robot turn around. The function reads the current angle and makes the wheels turn (in opposite direction) as long as one of the two wheels as not turned for 180 degrees.

Encoders

This function reads the values of the encoders as a certain voltage and returns them as an angle in degrees.








Brushless motor

The brushless motor requires an initialisation.


Initialisation loop










Infrared sensor

Reading the values of the infrared sensor. These values are read during a certain time and averaged to make sure that noise or other wrong peak values make the robot turn around.

When not at an edge, so small values of the IR sensor, the robot drives straight with the function advance. At the same time also the brushless motor is controlled using the setSpeed function.

If the value is larger than 120, which is a experimentally obtained value, the robot is at the edge of the table. In this case the robot is stopped and turns around.


Computer Aided Design Software

To build this project, we had to be able to design our robot on the computer. The aim of that is to know the exact dimensions of our pieces and notice before starting the construction that things would go wrong. The program we used was INVENTOR.

FabLab

When the design on computer was done, we had to build the robot. Few years ago, the robots could be made thanks to different techniques : turning, milling, drilling. Today, the technology evolved and we used for this project laser cutting to cut our plates of plexi and 3D printing for complex pieces. The machinery was available for us at the FabLab

Eagle

The PCB is an important part of the project. It enables to connect the microcontroller with ll the different parts of the project. The creation of it requires to be precise on the band width and the place of everything. To do it, we used a program, which gather a lot of electrical components to build those boards, called Eagle