One-Hour CoasterBot

Basic robotic DIY: minimal effort, maximum fun

By Matt Mets
Robot Build Banner

Difficulty: Intermediate
Time required: 1 hour

This is a step-by-step build of last year's CoasterBot 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 bot-building knowledge to the next level.

Required Parts

CoasterBot Kit P/N 2115741
To program the Ardweeny use
USB-TTL programmer P/N 2117341 (not included in kit)

Required Tools
Needle Nose Pliers
Scissors
Soldering Iron
Rosin core solder
Wire cutter/stripper
CD's

Coaster Bot

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!

Parts List Breakout
Standard Deluxe Servo (395760)
Breadboard (20601)
5V breadboard regulator (2115750)
Ardweeny Microcontroller (2115768)
Wheel & Tire Set (2109624)
5A toggle switch (317287)
3A basic switch (188867)
Motor driver (1341966)
22 AWG solid core wire 100 ft (36792)
4-AAA battery holder (216339)
9V battery snap (11280)
# 4 - 9/32 washers (106826)
1/4" male/female hex spacer 1.5" (139205)
1/4" male/female hex spacer .75" (139222)
4-40 hex nut (40943)
Screws PPN 4-40 x 1/4" (2094389)
Double sided tape
9V battery
(2) Dead CDs/DVDs



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