Week 5 - 3/3/2017

 Just to confirm at the beginning of the session the individual circuits were tested separately and as a whole as we didn’t need any more issues to arise at this point in the proceedings. After confirming that they each work, the circuits were then connected to the Arduino board and ultrasonic sensor.

The Ultrasonic sensor was attached to the Mobile platform using a smaller breadboard that can just sit at top of the mobile platform. This is then connected to the Arduino which we have been able to re-wire so that it takes its power source from the batteries rather than having it plugged in to the main power or a laptop.

For the Arduino to control the robotic car, two separate programs were written, the first for the line sensor and motor drive circuit, therefore knowing which way the wheels were going to turn depending on which way the path was going, which is what the sensors will relay the information back to the Arduino to complete the loop of the program. The second program is for the ultrasonic sensor circuit, this sensor is going to continuously take measurements of the path in front of the car, then when these measurements get to a certain distance that still gives us a turning circle distance for the car before reaching to object that is blocking the path.

The 2 programs were tested on the Arduino board and each worked as expected, therefore our project is nearing completion. It was now time to fully connect everything and ensure that it works when placed on a path.

We tried to combine the 2 program together to get the final program. The combined program didn’t work in the way in which we expected. The robot is meant to:

-follow a line

-stop if it finds an obstacle less than 25cm away on the track

-move when the obstacle is removed

(possible extension is for the robot to then rotate until it finds a new track, without an obstacle, to follow)

With the combined program the robot can follow a line but doesn’t respond to an object in front of it. Which is not what we thought we had programmed the Arduino to react to. This is more than likely to do with an error within the code and should easily be rectified before the bench inspection in a weeks’ time.

During a discussion we had a concern that may be an issue within how the RC is programed in its basic electronics; the robot might appear to follow a black line but actually avoids it, the line sensor gives logic 1 on a white surface and logic 0 on a black surface so when on a black surface, it moves in a direction to avoid it, we might have issues with tight bends on the track, meaning if it goes off track it will continue moving.

Also we decided on a final track circuit for the car to follow. We wanted to ensure that there would be turns and options for the car, due to the current standings of the car not re-routing we have chosen to design a single lane track but this could change if we can fix the coding of the Arduino.