Light Following Hardware Robot

Make this light-following robot just using hardware design! No coding is required and everything is linked! This robot simply follows a bright light and goes towards it. Let's get crafty!

I first made this for a school project and it's been one of my favourite projects in my Design technology class, I hope you like this robot as much as I do.

Skills/Special Machinery Needed:

• Basic understanding of electronics
• Basic Understanding of hardware design and the use of an IC
• How to solder
• Some knowledge of mechanics
• Access to a 3D printer

Good to know:

This is a complicated circuit so it would be best to send this circuit to be made into a PCB with an external supplier. I have linked the company I used to make my PCB.

1 IC LM358P

1 8pin IC holder

2 Transistors BD139

2 1kΩ resistors

2 100kΩ resistors

2 10kΩ resistors

2 blue LEDs

2 LDRs

2 diodes

1 100µF Capacitor

1 50k Potentiometer

1 battery pack

2 wheels

2 motors

2 small perf boards

1 switch (optional)

a couple of nuts and bolts

a couple of jumper cables

access to soldering iron and solder

access to a 3D printer

Autodesk account for Fusion360

some budget for the PCB (I spent approximately 2 USD for 8 PCB boards)

some passion and creativity!

First, we need our PCB to get things started. The schematic for this PCB is attached as a photo above but I highly recommend using my already-made file and sending this to an external supplier. The photos are the schematic, the PCB layout, and the PCB design red is the top blue is the bottom.

This Google file has everything needed for your circuit (This includes the Gerber files that you will need to send to the external supplier)

https://drive.google.com/file/d/13iip1R1UNj7a4yf4HGUV1jxkZFb22mx1/view?usp=drive_link

This is the external supplier I used to get my PCB

https://jlcpcb.com/

So how does this circuit work?

This circuit has 2LDRs, the input, the off-pound IC, the process, and the motors, the output. The left and right LDRs are light sensors that will give different voltages, the IC will compare the two and then "tell" which motor to move so that the robot moves towards the light.

We will need to connect 2 motors to our final PCB so it is a good idea to pre-make the motor so that it is connectable via jumper cables. Mine was very simple as I screwed the motor on a perf board and then connected male-female jumper cables to it.

After having received the final PCB put in your components and make sure that if they are polarised components they are put in correctly and check where each component goes. The photos should be clear enough to check where each resistor goes. Solder accurately and quickly so you don't burn the PCB and accidentally damage the circuit.

Tips

• Make sure to tin the ends of the wires
• Try not to burn the PCB by soldering quickly and efficiently
• Tie hair up
• Wear safety glasses if needed

To make sure things go smoothly, always test your circuit. You should test in between soldering with a multimeter to make sure you don't create a short circuit and also when you have finished soldering to see if the circuit actually works. The video linked shows the circuit being tested. You can hear the motors and the blue LED turn on when direct light activates the LDR.

Using Fusion you can make a holder for your PCB to be able to attach the PCB, motors and the power source (a battery pack). I built a simple hollowed cuboid without a bottom using a 3D printer so that the top can have the PCB stuck on, the bottom secure the battery pack and 2 holes on the side to allow the motors to be drilled on.

Link to my Fusion360 Holder Design

https://a360.co/48vjHaA

Open this file in Fusion360 and download this file. Then, 3D print this Body how you would with your 3D printer software. (If you need to make necessary changes to the length, width or diameter of the holes for the bolts please do so)

I use double-sided foam tape to stick my PCB and battery pack, a nut and bolt for the motors and modelling wire for the 'sleigh' (This sleigh is for balance and easier manoeuvring)

You made it!

Your final product should look like this and perform like the video attached.

I hope you enjoyed this project from the process to the final outcome. Please leave any comments and suggestions if any below!

Disclaimer*

This is not the most perfect circuit or build, please feel free to comment with any constructive criticism or suggestions. This is my first time making an instructable too.