Line Following Obstacle Avoiding Maze solving Robot part2

Line Following Obstacle Avoiding Maze solving Robot part 2

• PART1 System Design
• PART2 Mechanical design
• PART3 Motor control
• PART4 Electronic integration
• PART5 Software development 
• PART6 Final Code

Continue from Part 1

Mechanical design

• 2 wheels of 6 cm diameter
• 1 Castor wheel
• Acrylic sheet
  
  

Electronic component overview

Arduino microcontroller board

Microcontroller	ATmega328
Operating Voltage	5V
Input Voltage (recommended)	7-12V
Input Voltage (limits)	6-20V
Digital I/O Pins	14 (of which 6 provide PWM output)
Analog Input Pins	6
DC Current per I/O Pin	40 mA
DC Current for 3.3V Pin	50 mA
Flash Memory	32 KB (ATmega328) of which 0.5 KB used by bootloader
SRAM	2 KB (ATmega328)
EEPROM	1 KB (ATmega328)
Clock Speed	16 MHz

Power supply:

• Internal or on-board Supply
• External Supply

There is no fixed stipulation (unless specified for a competition) of which one you should use, just a matter of preference and resources available. The voltage should be equal to the rating of the motor (which is assumed to be the highest in your circuit) and should be stepped down to power the other circuit components. Internal or on-board supply requires batteries, which have to be rechargeable because you’ll run through alkaline batteries faster than you know it. If you get rechargeable ones, you’ll need a charger too. The current capacity, the weight and the rating of the battery also has to be accounted for. If you’re using alkaline batteries you can make a pack out of them by connecting them in series and parallel. New technologies like Lithium Polymer and old ones like Nickel Metal Hydride are easily available, though may seem a little expensive. Remember PWM will make the motors draw currents in bursts of a few milliseconds apart. Some battery technologies cannot handle drawing so much current in such little time. This ‘abuse’ can even damage your battery! Consider all these factors in designing your on-board power system. Consider buying or salvaging a battery holder from a gadget like an old toy car. They are helpful and neat! Check for sizes and shapes though, as 9v batteries are sometimes more useful than ‘AA’ sized ones and may have higher current ratings. A voltage regulator IC connected to a 9v battery would look something like this.

NEXT