Grid Follower (nexus IIT Bombay)

So as usual there is Nexus at this time of the year and looking at the problem statement i decided to ditch the event but...nancy was enthu about it so we all(me, mishel, nancy and chinmayee) decided to go for it with less than 2 weeks left for the event (more than enough anyway). By the way we won first place and kicked some a**.Check out the video here.

THE BOT:

I decided to get rid of the chassis and instead use the pcb itself as the base and attach the motors to it.

Specs:

THE MOTORS are rated at 12v and 420rpm they've become my favorite recently , been using them in most bots, they are small and give sufficient torque.(check out the pic).


We used standard 5mm IR DIODES AND EMITTERS , they have an angle of acceptance of 5 degrees, which is a good thing since they are directional the entire arrangement will be reliable because the emitters of one pair do not interfere with the other.


The sensing resistors are 10 k and each of the emitters are getting about 20 mA (which makes them pretty bright) .Refer to the circuit diagram at the end .

The micro-controller is an atmega 168 and we used a l293d for the motor driver

                                                                                                         This is how it looked after the assembly

We initially put two wheels in the front ,but later replaced them with a caster wheel (cause three wheels will always stay on the ground as all of them will be in one plane)

The sensor board is detachable and we put burg strips in front to protect the sensors

The green module you see on the top is a rf transceiver module based on the cc2500.(bought from robosoft systems)


I used a LM7805 as the voltage regulator to provide the 5v supply needed for the micro-controller.


This is the motherboard you ca see the slots for the micro-controller and the l293d in this pic

 Software:

We used arduino as the platform for this bot. the micro-controller has arduino firmware and is programmed in system using the rx,tx (usart) pins with connectors coming from the arduino decimilia board.

We used the flood-fill algorithm to find the shortest path to the destination,it optimizes the path and returns the path with the least distance and the least number of turns required.

You can checkout the code here.