Building your own robot seems to be a lot of fun. However, building robots can be quite expensive. Most robot enthusiasts estimate an expense of about $200 to $400 for even a tiny, but functional robot. This tutorial provides a step-by step guide on how to build a car-like robot well under 50$.
Electronic Materials Needed
- Two Hitec HS-311 servos
- 5 volt linear regulator
- ATmega8 AVR
- 28 pin
- DIP socket
- 220uF+ electrolytic capacitor
- Two 0.1uF ceramic capacitors
- Two 36 position breakaway male headers
- Five 340 ohm resistors
- Five CdS Photoresistors
- Grid type PC board with 356 holes
- 4 AA battery holder
- On and off switch
- 9 volt battery
- 6v 1400 mAh nickel metal hydride battery
- AVR STK serial port dongle programmer
- AVR ISP2 programmer
Non-electronic Materials Needed
- Water bottle
- Popsicle sticks
- Duct tape
- Soldering iron
- PC with a serial port or a USB2.0serial port adaptor
- Four 1.5 volt batteries
- Safety goggles
Steps to Build a Robot
- Begin building the chassis by cutting out wheels with a 6-inch diameter from a piece of cardboard.
- Modify the servos to provide your robot the means to drive. Unscrew the screws mounted on its corners and open up the servo to expose its internal mechanism. Find the pot by pulling off the largest gear, then plug in the servo’s controller. Set it to zero degrees. Rotate the pot to stop the gears from moving. Fix the pot in place by setting it with glue. Find and remove the stop on the main gear. Take out the slot found inside the gear that was attached to the pot. Reassemble the servo the same way you found it.
- Proceed to finish the chassis by taking out the screw that connects the motor to the small wheel. Cut a small hole at the center of the wheel and attach the freshly removed screw through it. Fasten the servo mounts to the base of your servos. Mount the servos on a piece of cardboard or firm plastic roughly cut into 3 inches by 6 inches. Fasten them with the screws that came with the servos. Ensure that the wheel section overhangs on the platform’s short side. Stick the servo and cardboard wheels together with tape. Attach the wheels to the servo and tighten the screws.
- Build the castor using a small water bottle. Cut the top part off the water bottle, giving it a roughly equal width all the way down its body. Set the bottle between the servos and secure it to the chassis with rubber bands.
- Start building the robot’s electronics by mounting the NiMH battery pack onto the chassis with tape. An AA battery pack with the same amount of power may also be used for this purpose. Solder and connect all the components to your PC board. If you are uncertain on how to do this, seek the help of someone who has working knowledge on electrical components. Lastly, plug in the servos, battery, photoresistor, and the serial cable onto the PC board. Affix the board into the bottle set at the front of the robot.
- Download the WinAVR, PonyProg2000, and AVR Studio if you want to create your own programming for your robot. If you do not have a background in programming, you may download basic robot programs online such as the one found at http://www.societyofrobots.com/downloads/sbs_source_photovore_v1.zip. Use the code provided with the AVR Studio program.
- Connect the robot to the computer and launch PonyProg2000. Determine to which port your robot is connected to and select it in the PonyProg2000. Write the program to your robot by selecting the “Write All” from the Command menu. This process takes about 30 minutes to an hour. Your robot should be fully functional after writing the program.