Introduction: Raspberry PI-based, Phone-controlled, First-person-view Lawn-mower.

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Meet Lawny! It’s a lawn mower with a first-person view camera that allows you to cut grass while controlling a remote-controlled robot!

I’ve built it using a Raspberry PI, H-Bridge, electric motor, and camera. It can be controlled from a mobile phone or a desktop.

The project's main idea is to control a lawnmower using a phone and see the exact same picture as a lawnmower.

Here is the full video of its creation and all the concepts that are described in this article:

https://www.youtube.com/watch?v=4OQUo0V-8QY


Supplies

Step 1: System Design

I have a Steel Razors Trimmer Head. If I add an electric motor, it will be a grass cutter. The motor rotates the blades, and they cut the grass. Simple.

If I want to control the motor, I need a relay and a controller. In my case, I used a Raspberry PI 5 (because I had it). However, any Raspberry device could support pulse width modulation and a camera.

That will be a static lawn mower. But I want to cut grass everywhere, not just in one spot, and I want to be able to turn the mover left and right.

So I am adding two more electric motors. The construction will be heavy, so I need power, not speed, and I will use windshield wiper motors from a real car.

The first limitation is that I need two Pulse Width Modulation channels to control a single motor. But I have two motors, which means that I need four channels. To solve this problem, I am adding two more relays to switch the signal between pins. Further, I need to see where the lawn mower is going, so I am adding a camera module to the Raspberry PI. Additionally, I need some power sources. To prevent power drop elements that consume a lot of current, I will use a separate battery for the motors and a power bank for the Raspberry PI and electronics.

And finally, I will control this system from a mobile phone with a cross-platform application through wi-fi.

Step 2: Cutter Box

The cutter box is made from plywood. It has a hole for the motor in the middle.

Step 3: Mower Body

The next is to create a body. I am adding a few more surfaces to make that mower move.

Step 4: Join Cutter Box

Connect the cutter box with the body using slides.

Step 5: Paint

Paint all surfaces

Step 6: Place Electric Components

Place electronic components:


Step 7: Add Wheels

Step 8: Add a Blade

Step 9: Assemble and Test

The full video:

YouTube

The source code

GitHub