View Full Version : Nuntius: The Garden Avenger Robot

07-28-2011, 01:58 PM

A couple of years ago I first saw one of those self contained game systems that consist of just the joystick and the AV wires that you plug into your TV. I was simply amazed at the simplicity and brilliance of the concept. You just plug it in and play.

Nuntius is based on the same basic concept of those systems except it's a robot. The controller it a biomechanical input device that consists of a propeller proto board that measures the position of a 5 + gripper axis "mini arm" that you articulate with your hand just like you would if you were actually there. The propeller then send the data via a XBEE to the robot. The result is that the big arm on the robot mirrors the mini arm and you control the robot by looking through a wireless camera that's attached to the gripper. The movement of the robot is proportional to the direction and how far the arm is extended (or pulled back for reverse). The further the arm is extended, the faster it goes in that direction. The robot only moves while you're holding down a button on the proto board. This allows you to drive the robot around and then stop and examine something with just a button and the mini arm. You just plug it in and do whatever... weed the lawn, weed the garden, weed the driveway, take the dog for a walk... from the safety and comfort of your couch. http://forums.parallax.com/images/smilies/smile.gif


Major components:
2 Propeller proto boards
1 Propeller proto board enclosure
2 XBees
1 Parallax Wheel Kit
2 Parallax HB-25 Motor Controllers
Servos and Servo Brackets from Lyxmotion
Wireless camera

Video: Nuntius the Garden Avenger vs. The Weed!!!


07-28-2011, 02:15 PM
Well done Nuntius.. got that pesky weed..

Love it

07-28-2011, 02:55 PM
Ha ha, thanks. I met my new next door neighbor for the first time while I was filming yesterday. I think he's going to try and avoid me in the future. :)


07-28-2011, 03:30 PM
Great construction! It might need a more malicious looking grabber... ;) or even a clipper at the other end of that fore-arm (e.g. a nice counterweight instead of the springs)

I'm curious to know what wifi camera that is, and how its performance is? (e.g. connectivity, blurriness when bouncing over terrain)

07-28-2011, 04:05 PM
Hey Gertlex ,

Thanks, the camera is actually a cheap 2.4 Ghz wireless camera that I bought on Amazon for ~$28 and you have to tune the video receiver with the knob on the side. But!, the way the picture tunes in, it makes you feel like you're in one of those old 80's movies like the "Abyss", or "Aliens." I went with the non-wifi camera because I wanted the whole thing to be just like one of those "joystick" games where you just plug it into the TV. I think that you could get much better reception with a wifi camera or if you spent more than $28, but I think it's a great camera for that price. It even has sound so that you can hear the plant being pulled out of the ground.


07-30-2011, 02:06 PM
Sweet robot! I like the efficiency of the design!

07-30-2011, 06:04 PM
Hey thanks darkback2, I'm glad you like the way it looks.

Originally I was going to just make a rectangle base, but then thought that would be kind of boring and I wanted it to be able to push it's way through tall grass or small brush so I sketched out some lines on the board and made some skid covers for the wheel gear boxes (otherwise they might catch or get tangled up with something). I'm really happy with how the overall design turned out. I like the shape and the way the wheel motors kind of look like they're submerged in the base. I might have gotten carried away with the size of the battery, but this is my first non walking robot so I was excited about not having to worry about weight plus I wanted to make sure that the robot was stable, even while it was driving around on bumpy ground with an arm swinging around. Aesthetically, I think the battery fits well with the overall look and helps give it an animal/insect quality and I probably won't ever have to charge it again. :happy:

That reminds me of a funny side note: While I was calibrating the algorithms for converting the "mini arm" positions to the robotic arm late one night alone I forgot that the robot was behind to me and mimicking my movements (I was recording the max and min values). All of a sudden I felt this weird, tentative movement on the back of my arm and I jumped a little. :eek: You can tell that it's movements are diffidently not pre-programed.