Arduino RC Controlled Lawnmower Project

Using the guts from a push-mower, two wheelchair motors and a custom carriage, and some hand-built electronics, Instructables user Johndavid400 has created a radio-controlled lawnmower dubbed the Lawnbot4000. His detailed writeup is available here.

lawnbot4000
lawnbot motor lawnbot wheels lawnbot top

Background:

Most R/C equipment comes packaged for a single specific use, which makes it easy to use but is very limited in what you can do with it. So using the Arduino as an interpreter between the R/C system and the motor driver, I can use any motor controller that I want (depending on the size of the motor and power required), reprogramming the Arduino to supply the required signals.

What I ended up with:

After successfully hacking a few R/C cars from the thrift store, I got bored driving them around the driveway and I was having a hard time convincing my wife that there was any usefulness in the revived toy car. So I decided it was time to make my biggest chore at home, a whole lot easier and actually put my Arduino to work, and thats how I ended up building an R/C lawnmower.

While designing the lawnmower, I thought it would be cool to learn about the electronics that made it move, so I designed and built my own motor speed controller (or H-bridge) to power the lawnmower. I looked around at every H-bridge design I could find before deciding to go with a Mosfet h-bridge that uses both N-channel and P-channel Mosfets.

I built several different motor driver boards for this project, the first two were on Radio-Shack perf-board and the next 4 were designed using EagleCad and etched to a piece of copper-clad PCB, using the toner-transfer method. The most recent board is the one I use to mow the lawn as it has the ability to stay cool even while operating for long periods of time (30-40 mins straight) at 10-20amps and 24vdc. FWIW, I had to burn up a lot of Mosfets to find this out. If you want to see any of my other motor controllers, go to www.rediculouslygoodlooking.com and check out the Mosfet shield.

Here is what I bought already assembled:
– FM R/C transmitter and receiver pair from ebay = $40
– Arduino = $30
– I already had a used push-mower = $60

Here is what I bought and assembled into the Lawnbot400 (as I call it):
– (2) electric-wheelchair motors from ebay = $40 ea
– (2) 12v marine deep cycle batteries – Walmart – $60 ea new (used batteries might work)
– 36″ pieces of 2″ angle-iron (2) and 1″ square-tubing (2) from Home Depot = $8 ea
– 36″ pieces of 1″ angle-iron (2) and 1″ flat steel bar (2) from Home Depot = $5 ea
– (a lot) of nuts, bolts, washers, lock washers 3/8″ or 1/2″ with drill bit = $20
– (2) caster wheels from Harbor Freight Tools = $14 ea
– (2) drive wheels from Harbor Freight Tools = $8 ea
– (36″) 5/8″ threaded rod with several 5/8″ nuts and washers from Home Depot = $8
– (2) sprockets from Allelectronics = $5 ea
– #25 roller chain and a few universal links from Allelectronics = $10 for 3′
– sprockets from Electronics Goldmine = $1.50 ea
– (24) mosfets from Digikey = $1 ea
– (there were quite a few small parts for building the H-bridge, they are listed later on)

7 thoughts on “Arduino RC Controlled Lawnmower Project”

  1. Science channel going hard with the build up to the main event on Thanksgiving. SC LowerThird with Zach and yourself flying in during a Carl Sagan commentary on the universe is pretty wild.

  2. Really? I better tune in and check some of these promo spots out.

    Punkin Chunkin is Science Channel’s Superbowl – their big event of the year. It’s an absolute honor to be a part of it.

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