Build a CamJam EduKit Robot

The CamJam EduKit 3 is a fantastic robot kit that enables you to build a fully functioning robot with ultrasonic and line following sensors for just £17 / €19. All you need is a chassis and we’ll show you how to turn an old tin box into an amazing robot.

CAMJAM

The Cambridge Raspberry Jam (camjam.me) teaches children of all ages how to build electronics projects and the kits are sold to everyone via the Pi Hut. The CamJam EduKit #3 has everything you need to build a robot (thepihut.com/collections/camjam-edukit).

STEP 1

The CamJam EduKit 3 includes wheels, motors, a battery box, an EduKit Controller Board and two sensors. You also get a breadboard, wires and resistors to bring it all together, along with some double-sided tape. We suggest you get a USB battery charger, the type used to recharge phones, and a Wi-Fi dongle.

STEP 2

You’ll need a chassis for your robot. We’re using a tin box (the type you often get to keep knick-knacks in). You can use any flat surface as a chassis, so long as you can mount the wheels but using a container makes it easier to hold all the bits inside. You could also use a plastic Tupperware box or even the box that the kit comes in.

STEP 3

Flip the box upside down and make a hole in it in the middle, at one end. We’re using a metal drill to drill a hole through the tin box but if your box is made from plastic or card you could cut a hole using scissors. It doesn’t need to be large, just big enough to fit the wires from the servo motors.

STEP 4

Attach the two plastic wheels to the yellow servo motors making sure they’re on opposite sides. Now fix the servos to the underside of the box, making sure they’re near the hole you created. You can use the double-sided tape to mount the wheels but it’s a good idea to use Blu-Tack first to make sure the design works.

STEP 5

Place four AA batteries inside the battery box and make sure it is set to Off. Use a small screwdriver to loosen the two central screws in the EduKit Controller Board. Place the black wire from the battery box in the GND and the red wire in VIN (Voltage). Take a look at Worksheet 1 (camjam.me/?page_id=1035#worksheets) for more info.

STEP 6

Place the robot front away from you and attach the red and black wires from the right wheel to the block marked Motor A – it doesn’t matter which way around. Take the wires from the left wheel and attach them to Motor B with the wires the opposite way around from Motor A (see picture).

SETTING UP THE RASPBERRY PI

The Raspberry Pi will need to operate on the move, so it needs power and a wireless network connection. You’ll also want to access it remotely, so you’ll want to set up VNC. Let’s build the brains.

STEP 1

Install a fresh build a Raspbian Jessie on an SD Card. Use sudo apt-get update and sudo apt-get upgrade to get the latest builds for all your software. Now use sudo apt-get install tightvncserver to install VNC software. Enter sudo nano .bashrc and add vncserver to the end of your bash file so it starts at boot time.

STEP 2

Connect a Wi-Fi dongle to your Raspberry Pi and click on the Wi-Fi icon in the top right of the Xcfc desktop interface; enter startx if you’re not in the desktop environment. Choose your network and enter the Wi-Fi password. Open the terminal and enter ifconfig:
Make a note of your network address.

STEP 3

Charge up a portable USB charger, the type normally use for mobile phones and make sure it’s got plenty of juice. Shut down your Raspberry Pi and plug in the portable charger and make sure it can boot and run your Raspberry Pi.

STEP 4

Check that the VNC connection is working from another computer. On a Mac press Control-K and enter the vnc://192.168.0.[x]:5901 (with x the number from ifconfig in Step 2). Click Connect and you should see the Xfce desktop. Your Raspberry Pi is now ready to work remotely inside the robot.

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