Conclusion

Buggy Design

Our buggy design was simple and the chassis had three wheels, two at the back and one at the front. The original idea was to have the chassis as a platform for the circuit that controlled the rotation of the two back wheels. This meant that the circuit was untidy and it was difficult to keep the buggy stable. The LEDs and LDRs were placed in the right positions but because they were held down by tape they weren't held securely. Due to the breadboard not being stable on the buggy the LEDs kept short-circuiting. One major problem with design was chosing the right front wheel. Many designs were developed over several days and none gave the required turning. If the buggy could have been redesigned then it would have been made to be more stable. To do this the breadboard, micrcontroller and darlington driver would be placed securely on the chassis before completeing the circuit. A better caster wheel would have been used instead of a botched wheel.

Circuit

During testing the programmed circuit controlled the motors as it was supposed to with no errors. Two LDRs were used and placed either side of the black line and when both read light the buggy would move forward and when one read dark the buggy would turn. For example, if the left LDR read dark and the other read light, then the left motor would reverse and the right motor would move forward. However, this only worked well when the LDRs were covered but not very well on the track. Each LDR was paired with an LED and covered in black paper so that it had a control light setting. As the LED moved over the black line it would reflect less light into the LDR. The idea of using paper could have been improved if more time was available and LDRs and LEDs could have been secured properly. As this wasn't the case the LDRs kept detecting wide ranges of light and it was difficult to calibrate each time the buggy was used. Another improvement would be to use a third LDR in the middle that would always read dark and keep the buggy on the track at all times.