Line Follower Robot

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These are the instructions for making your very own line fallowing robot.


Tools You May Need

Tools You May Need
Scisers-tools.png You will definitely need some scissors. You will need them to cut the paper robot base and the foam tape. They also work for cutting the solid core wire.
Salt-tools.png Salt, pepper, sand, some sort of powder, this is completely optional. I'm not going to try to explain it now.
Screwdriver-mini-tools.png This is used to adjust the line follower sensor module. It's possible that it does not need any adjustment. If you do not have a screwdriver, you can try using you fingernail :)

Make Sure You Have All The Parts

Item Quantity Name Description
parts-001900.png 1 Robot Body This is the cosmetic shell of the robot. It gives the robot its humanoid appearance.
parts-000200.png 1 Robot Base This card is the support structure for the vibrating motors and the bristle base.
parts-001700.png 1 EB1 This circuit board is a computer. The is a circuit board has a micro controller unit ( MCU ). The MCU should, be loaded with the program needed for your robot to function. It is possible to reprogram the MCU through the USB plug built into the circuit board. Because the MCU is reprogrammable to do different functions it is technically classified as a computer. Because of the flexibility of computers they are not as fast at processing as an ASIC (application-specific integrated circuit). ASICs are designed to do one specific task and typically do it very fast or inexpensively. However computers because of their flexibility do the vast majority of processing in the world.
parts-000300.png 1 Battery This is a rechargeable lithium ion battery with an output of 3.6 volts. This batteries classified as LIR2032. The LIR represents "lithium-ion rechargeable". The first two digits of "20" signifies that the battery has a diameter of 20 mm. The last two digits "32" signifies that the battery has a thickness of 3.2 mm.

If you have the appropriate charger you can recharge this battery. However if the voltage drops to 3V or less the battery will be permanently damaged. So make sure to charge it regularly.

It is possible to use a standard lithium battery CR2032. However it's voltage is only 3V. The vibrating motors will not works well at this voltage. It is also possible to use a CR2025. This battery is only 2.5 mm thick. You may need to bend the tabs in on the EB1 circuit board to make proper contact with the battery. Because the CR2025 has less volume it will also have less capacity.

parts-001800.png 2 Vibrating Motor These are the same kind of motors used in the cell phones. These motors are not designed to run at 3.6 holes for extended periods of time. So if they seem to get hot you may want to give your robot a rest.
parts-000800.png 1 Double-Sided Adhesive Tape This piece was cut by a laser from a larger sheet of double-sided adhesive material.
parts-000600.png 1 Bristle Tabs This piece of plastic used to form the plastic tabs that will allow your robot to scoot across surfaces.

This piece of plastic was also cut by laser.

parts-000500.png 2 Rectangular Plastic Mounting Plate He's played are made of acrylic a plastic and also cut and engraved by laser.
parts-000700.png 3 Double-Sided Foam Tape Circle These double-sided foam tape circles will be used to mount the motors hold together other parts of the robot.
parts-000900.png 1 Solid Core Wire This wire has a solid core conductor which makes it stiff and useful for holding different parts of the robot together. Because of its malleable nature you can adjust the balance of the robot. This particular wire is 24 American wire gauge (AWG). You can learn more about AWG at
parts-000100.png 1 Jumper Cables These are 10 cm female jumper cables.

They are used to connect the Line follower sensor module to the EB1 circuit board.

parts-001300.png 1 Header Pins These header pins are used to connect the EB1 circuit board to the jumper cables.
parts-001000.png 1 Line Follower Sensor Module This module consists of a infrared LED and an infrared sensor. By detecting amount of reflected infrared light it can distinguish the difference between a black and white surface. You can adjust the triggering point between by adjusting the potentiometer on the other side of with a small Philip head screwdriver.

Keep in mind that this sensor can also be affected by sunlight. So if it's not behaving correctly, maybe move into the shade.

Start Building

Cut the control panel section of the card off, leaving only the tank tread part of the card.

Cut along the four short gray lines near the corners of the card.

Remove one side of the protective material on the double-sided tape.

Tear the tape into two pieces, place it on the card as shown in the picture above and remove the remaining protective material.

Find the laser cut piece of plastic and cut or tear it into two pieces as shown in the picture above.

Bend the plastic along the dotted lines, make sure each piece is symmetrical to the other as shown in the next picture.


Now place the bent plastic onto the double-sided tape. Make sure you get them both in the same direction as shown in the picture above

If the plastic tabs are pushed against the double-sided tape there is some risk that they will stick.

You can sprinkle some salt, flour or some other kind of powder on the double-sided tape to prevent it from sticking to the tabs.

The end result will look something like this.

For cosmetic effect you can curl the corners of the card to make it look more like tank treads.

For extra cosmetic effect you can bend the small corners

Now find one of the double-sided foam tape circles and cut it in half.

Remove the top protective layer.

Cut one end of it at a right angle.

Now place the vibrating motor on the double-sided tape. Make sure that the weight hangs off the edge of the tape and can spin freely.

Cut off the excess double-sided foam tape.

Remove the remaining protective material.

Place the vibrating motor with the spinning weight hanging off of the edge of the card ( as shown in the picture above ). Again make sure that weight can spin freely.

If you like you can remove the paper of off the clear plastic rectangles. .

Place the two of the double-sided foam tape circles on the plastic rectangles.

Remove the protective layer from one of the foam tape circles.

Place it on the bottom side of the line sensor module.

Now take the wire included in the kit. Folded in half. Start by placing the wire through the holes closest to the sensor.

Place the wire through all four holes as shown in the picture.

Add an extra zigzag. Later you will need to make some adjustments to the distance of the line sensor module to the surface. This extra better wire will allow you to make that adjustment.

Pull the wires through the second plastic rectangle.

Line Follower Robot-wire-little-bend.png
Add a step in the wire as it exits the plastic rectangle. This will prevent the wire from sliding back through the hole.

Now slide the wires through the hole in the circuit board.

Wrap the wire around circuit board to hold it in place. Later you will need to plug into your line detector module. So make sure to leave enough room for it.

Ideally the entire assembly should be able to balance on the bottom plastic rectangle. It's important that the weight be balanced once placed on the vibrating platform so that it will work more effectively.

Once you're satisfied clip the excess wire.

Remove the protective material.

Stick it on the vibrating platform.

Place the battery into the battery socket, with the plus side facing outward.

Fold the robot body along the torso and head as shown in the picture above.

Place the robot body on the circuit board.

On the head of the robot, fold and tuck in the tabs

It should look like this when you're done.

Plug the cable into the line sensor module.

Plug it into the pins labeled "VCC", "GND" and "D0"
VCC = (+)
GNG = (-)
D0 = is the digital output pin

Place the long pins into the circuit board as is the picture. Push the pins so that they protrude out the back.

Bitmap in BuzzBuzzBot-Line-Follower-Robot.cdr.gif
Plug them into the back of the circuit board as shown in the picture. Pin A0 on the line sensor module is not used.

2-Bitmap in BuzzBuzzBot-Line-Follower-Robot.cdr.jpg
I recently started adding this template to help people put everything in the right place.

Once the line sensor module is powered up you can start to tune it. You can adjust its triggering sensitivity with screwdriver.
you may also want to mess with its distance from the surface of the line.
This sensor works in the infrared spectrum. So it is affected by sunlight. If it is acting flaky maybe try it in the shade.

You can tell when the threshold is triggered by the "detector LED". When it is configured correctly, you will see the "detector LED" turn on and off as you slide the sensor over and off the black line.
You find your line is not black enough, I recommend using black electrical tape. It works best when you cut the electrical tape into thin strips and place them on the paper.
FYI: If the "detector LED" is not reacting, check to see that the "D0" pin is in the right location on the circuit board.

Once the line sensor module configured correctly, now you can add the motors.
Each motor should be connected to plus and minus.
You can swap the right and left motor by swapping the "A-" and "B-" pins.
You can change the direction of motor by swapping the + and - of the motor.

It seems that the propulsion through vibration works best when the motors spin in the direction of travel on the top side of the rotation. Much like the doggie paddle stroke.

Congratulations you are now ready to start the robot revolution!

Additional Information

Line Follower Robot Advanced

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