How to Build a One-Hour CoasterBot Robot

Minimal Effort, Maximum Fun, Get Creative

Skill Level: Intermediate
Assembly Time: 1 hour

This is a step-by-step build to the CoasterBot Design Contest we ran with MAKE. This is a build for a simple bot version. But don't stop there – add sensors, features and whatever! Take your basic robot building knowledge to the next level.

To program the Ardweeny use
USB-TTL programmer P/N 2117341

Coaster BotCoasterBot

Parts Used:

Qty. Part Description Mfr. Part No.
1 Standard Deluxe Servo 33322
1 Breadboard WBU-301-R
1 5V Breadboard Regulator 34020
1 Ardweeny Microcontroller KARDW
1 Wheel and Tire Set 28109
1 5V Toggle Switch 1MS9T6B11M1QE
1 3A Basic Switch D2F-L
1 Motor Driver L293DNE
1 22 AWG solid core wire 100 ft. #9313-0-R
1 4-AAA Battery Holder SBH-441-AS-R
1 9V Battery Snap A104-R
1 # 4 - 9/32 Washers #4FW-R
1 1/4" Male/Female Hex Spacer 1.5" 2112-440-AL-7
1 1/4" Male/Female Hex Spacer .75" 4538-440-AL-7
1 4-40 Hex Nut 36012
1 Screws PPN 4-40 x 1/4" 28631
1 Double Sided Tape 051131-06439
1 9V Battery ALK 9V 522
1 (2) Dead CSs/DVDs

Required Tools:
Needle Nose Pliers
Soldering Iron
Rosin core solder
Wire cutter/stripper

Step 1: Gather Your Parts

Gather Your Parts
First with all projects it's important to do an inventory check. You never know when you'll end up with less than the required pieces, so take the time to look through each bag. Who knows, you might even end up with some useful spares. These instructions assume that you've already assembled the Ardweeny and the Solarbotics Power Regulator based on the instructions that came with them.

You also need to hack your servomotors for continuous rotation. One of the CoasterBot contestants created this handy how-to.

Step 2: Understanding the Circuit on the Breadboard

the Breadboard
Circuit on the Breadboard

Pictured is the breadboard, which acts as a big interconnect for the electrical parts. It allows you to easily hook up power and other control signals without running too many wires. Each shaded section can be used to make a single connection or node in a circuit diagram. The two side sections are reserved for power- the black areas are connected to ground (-), while the red areas are connected to power (+). The second picture shows the circuit we are going to make with the exact placement of each component and wire on the breadboard.

Step 3: The Breadboard Power Supply

The Breadboard Power Supply
Solder the red (+) wire of 9V battery snap to the metal tab on the back of the Breadboard Power Regulator power jack and the black (-) wire to the metal tab on the side. Plug in the 9V battery and flip the regulator switch ON. If the red LED on the board lights up - well done! Flip the switch back to OFF.

Step 4: Breadboarding the Core Components

Breadboarding the Core Components
Plug the basic components (power regulator, Ardweeny, and the motor driver) into the breadboard.

Step 5: Connecting Power Wires

Connecting Power Wires
Connecting Power Wires

Once the components are in place, the next step is to place jumper wires to ground any component leads that need grounding, (pictured in black). Next, connect the wires to the pins that require power, (pictured in red).

Step 6: Adding Motor Control and Motors

Adding Motor Control
Adding Motor

The final set of jumper wires runs between the Ardweeny and the motor driver. This allows the Ardweeny to control the motors, (pictured in orange). Next, connect the leads from the continuous rotation servos to the motor driver chip. Connect one motor to each side of the chip. We'll sort out which direction is which in the software later!

Step 7: Adding the Battery Power Pack

Adding the Battery Power Pack
The last thing to hook up is the AAA battery box to power the motors. This plugs directly into ground and pin 8 on the motor controller.

Step 8: Downloading the Sample Code

Downloading the Sample Code
Your CoasterBot brain is all wired! The next step is to download a program to the Ardweeny to make the robot work! Make sure you have the Arduino software set up on your computer and then upload this code to your bot. If everything is set up correctly, the motors should start to spin in a pattern!

Step 9: Assembling the Chassis

Assembling the Chassis
In order to get your bot moving, you'll need some wheels. To get you going as quickly as possible, we present our patented method for making a quick robot: double-sided tape! For this simple chassis, we'll skip the screws and glue, and use double-sided foam tape to patch everything together. It should work great for prototyping, (kit includes screws for a permanent bot chassis).

Step 10: Attaching the Servos to the Bottom CD

Attaching the Servos to the Bottom CD
Attaching the Servos to the Bottom CD

Cut two pieces of sticky tape and stick them to one of the servo motors. Stick the servo near the edge of one of the CDs. Repeat for the second servo, making sure to leave enough space between them to fit the AAA battery pack

Step 11: Attaching the Top CD to the Servos

Attaching the Top CD to the Servos
Attaching the Top CD to the Servos

Add some more tape to the top of both servo motors. Stick down the second CD, making sure to align it with the first.

Step 12: Installing Breadboard and Battery Pack

Installing Breadboard and Battery Pack
Coaster Bot

Stick tape on back side of the breadboard and secure to the top of your bot. Place the 9V battery, using tape, between the CDs. Bot build complete! Plug the motors and battery pack in and the spinning motor test code from before should now let your robot do a little jig! We suggest you do one as well to celebrate!

If you've made it this far, you now have a functional robot body to start playing with. Next steps are to let your imagination run wild, add sensors, a camera, or transmitter. Happy botting!

CoasterBot was a joint adventure between Jameco and MAKE intended to inspire the bot builder in all of us. Original build details here.