Micro Mouse

Jatin PasrijaPrateek AgrawalShashank SinglaSushmita Rawat

Project Statement We had planned to work on micromouse which is a maze

solving robot. The project incorporates implementation of a maze

solving algorithm on a actual piece of hardware which in this case is a free to move 2 wheeled machine (motor driven)

The first phase of our project was to design the robot capable of all degrees of motion + implementation of sensors +control of the two stepper motors installed on the robot based on outputs from a PIC (Programmable IC) Microcontroller. We also planned to use ADC (Analog to Digital Conversion) for the sensors in our robot.

The next phase consists of actually calibrating the sensors, programming the robot, installing radio communication in it +installing LCD in it for getting feedback from the robot.

What is a Micro Mouse A Micro Mouse is an

miniature electro-mechanical robot, typically consisting of three main subsystems: The drive system, an array of sensors, and the control system. Its purpose is to find its way through ANY type of maze - in the shortest amount of time. It integrates several different disciplines of engineering, ranging from electrical to mechanical to computer science

Micromouse – Building Blocks Chassis The chassis needs to

hold two motors, sensors, circuit and the power supply. It has been made using two aluminum angles. The robustness and flexibility of the robot depends on the chassis.

The chassis has been kept simple and of light weight.

Wheels The wheels are a crucial part of the robot

and they must be very precise in their size for the straight motion of the robot.

We had earlier bought wooden wheels manufactured, however these were of insufficient strength and broke up after a few rounds of testing

Then we procured aluminium wheels from the manufacturing lab.

Sensors

Side- looking sensors to measure the distance from the wall and detect their absence/presence.

We have used three sensors, one in front and one on each side of the mouse, thus allowing our robot to move in one direction properly.

We prepared IR sensors ourselves.They were working but for short distance only. So, we procured modulated visible light sensors.

Motors Stepper motors suits for

the needs. Those which come out of old electronic gadgets are more than sufficient.

While choosing a stepper motor for a micromouse, we kept few things in mind. We need to look for motors with low voltages and higher current ratings. This holds true for unipolar as well as bipolar motors.

we have two motors properly fixed into the chassis.

Motor Driver

  We have used IC L298 as the motor driver for our stepper motors because of its high current capabilities.

Driver Circuit

LCD Screen

LCD is an extremely handy debugging tool. We have used a 16x2 LCD that has a contrast-setting pot and a backlight switch soldered on to the back.

We have used the LCD for two main purposes: We can display all the sensor readings on the LCD so that we could observe and note the readings as the mouse moves through the maze.

We can also calibrate the mouse easily using the LCD, since, instead of reprogramming the PIC every time, all we have to do is create a menu interface and change the values of ‘parameters’.

Power Supply

 We’ll need a 12V battery as our power supply. So we have procured 10, 1.2 V Ni-Cd batteries for this purpose because of their better performance and low cost.

Wireless Module A simple micromouse

usually consists of an onboard LCD display and switching mechanism.

However, we intended to go a step further by wirelessly transmitting the data to the LCD, and perhaps even calibrate the program wirelessly.

This will require an RF module working at 413/433 MHz

We have left the space for the hardware on our main circuit board. But we need to procure the same and place it.

The brain We have

used microcontroller. PIC 18F4550, a very powerful chip, supported by Microchip’s C18 C compiler.

Micromouse demands a lot of processing power, a good onboard ADC (Analog to Digital Converter) and lot of multiprocessing tasks (good set of timers), this PIC has got it all. Although there is no free running ADC mode, the actual conversion time is really small.

All the programming for the micromouse has been done in C.

Summary of work done Build the chassis Procured Motors , batteries, LCD, PIC, Motor

Drivers etc. Made the sensor plate containing three sensors Placed the sensor plate on the chassis.

(placement needs to be accurate) Have made the basic circuitry for our micro

mouse, which include the PIC circuit, LCD module, Sensor Ports and motor drivers , including space for RF module and tested the same.

Cont..

Worked out the LCD code. LCD is now working and displaying data.

Sensors have been properly cascaded with the main circuitry and the data from same has been made available on LCD for calibration.

Code for motor driver has been written.

Still to do………. Procure wheels from the

manufacturer Test the motor driver code. Work on the RF module. Write the code for solving a maze. Finally coordinate all the individual

blocks (through coding) to get a working micro mouse.

Test it. (construct a maze it)

ESTIMATED BUDGETEstimated Cost in Rupees-> Chassis - 500 Stepper Motors - 1000 Wheels - 200 Motor Drivers - 300 Microcontroller - 300 Sensors - 300 Electronic Components - 200 16x2 LCD - 120 RF Module - 350 Battery - 600 TOTAL->Rs 3870 BUDGET INCLUDING OVERHEADS->Rs 4000/-