DIY Radio Controlled Lawnmower

ADVANCED INTERFACE

 

A TRUE DO-IT-YOURSELF Radio Controlled Lawn Mower!

all material here is copyright Terry Creer 2007

 

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DISCLAIMER - THE METHODS OF CONTROLLING AN UNMANNED VEHICLE DETAILED BELOW ARE POTENTIALLY LETHAL. YOU CAN KILL SOMEONE, AN ANIMAL OR A ROSE GARDEN IF YOU ARE NOT CAREFUL. I ACCEPT NO RESPONSIBILITY FOR LOSS OF LIFE, BEER PRIVILEGES OR SEX FOR CONSEQUENCES THAT ARE BEYOND MY CONTROL. IF YOU DECIDE TO BUILD A MOWER LIKE MINE YOU DO SO AT YOUR OWN RISK. BY BUILDING THE PROJECTS STATED BELOW YOU ARE ACKNOWLEDGING THAT IT IS ONLY YOUR FAULT IF SOMETHING GOES WRONG.

 

OPTION 2 - The Not-So-Simple Approach

Bits required:

1.      2 channel hobby RC transmitter and receiver

2.      2 x 3 pin female to female Servo leads - available through hobby stores, or make your own

3.      5 pin plug to connect the converter PCB to the Wheelchair controller's Joystick connector.

4.      RC to Joystick Converter Assembly (Details Below)

 Get the Schematic, PCB and Assembly details HERE

Constuction:

 First of all, here's the wheelchair controller box:

       

1.      The battery charging socket is on the front panel. The green button is the main power to the controller. The joystick can be seen on top - this will be replaced by my controller

2.    On the rear panel is the socket for the main wiring loom. Above it is a dial used to limit the top speed of the wheelchair... I mean lawnmower - handy!

3.    Side view. This is a BEC controller with (very old) Dynamic Controls internals

 Time to dismantle it. Taking off the front cover, we can plainly see the connector for the joystick (pic 1 below).

Go about removing the joystick altogether. Save it for a future project :)

   

CONTROLLER INTERFACE V1.0

 Here's how I made the first controller. I apologize in advance that this version is a bit of a hack job and a proper PCB doesn't exist for it. You must make the PCB provided and perform some modifications to it to get it up to scratch. Alternatively, you can download the PCB file provided in the DOWNLOADS section and modify it yourself before building.

If this doesn't appeal, I am working on version 2.0 which is MUCH simpler and easier to build (not to mention cheaper).

If you're REALLY keen to get yours going, maybe the SIMPLE approach will do until Version2.0?

Otherwise, here's how I got Version1.0 going:

Get the PCB file and Schematic from the DOWNLOADS section.

The Schematic is up to date and if you're savvy on reading this, you can tell what modifications need to be done. Unfortunately, I don't have the schematic that matches the PCB :(. I accidentally over-wrote it :-x

See the pics below for extra details (click to enlarge and show modification details)

               

       

PUTTING IT TOGETHER

The next step is to squeeze the controller interface along with the RC Receiver into the original wheelchair controller box.

First, pop the end off the box (only 2 screws on mine)

         

       

Before it all went back together, I needed an exit hole for the receiver's antenna, so using a hole that was already in the controller (previously a mounting hole), I took an M5 bolt, drilled a hole thorugh the centre of it, and placed it through the mounting hole from the inside facing out.

Then I threaded the antenna wire through it from the inside like the pics below. Getting the controller box open was tricky at first. It required two long brass pieces of wire to be knocked out through two channels near the joins on the two halves of the box. Once I worked that out, it was easy to split it open.

       

   

Once it was all back together, I sealed the hole where the joystick with a custom perspex cover my mate Jamie made (thanks dude!). This way I could see the calibration LEDs easily everytime I turned on the controller.

Lastly, I made a strong, but flexible antenna tube out of a black irrigation sprinkler riser and screwed it down onto the exposed thread of the bolt where the antenna wire exited the controller box.

Voi la! The controller is done!