Playing with kits
Oh, great!
After typing for about 30 mins and trying to insert a pix the Wintox security kicked in to block a pop-up and I’ve lost all the typing!
To start again…
I’ve been playing with some of the kits I had laying around during the week, and getting to know them.
First off is the Robo-11 from Inex. (There are a few Inex’s around; but the company I’m talking about is at http://www.inex.co.th).
My first impression was not good. All the parts were cheap plastic and all the bolting was done with washer-less steel. Result — massive slippage since you can’t always get a spanner into tiny spaces.
But the kit itself provides quite a few sensors — 3 linetrackers, an IR ranger, 2 touch sensors, and 2 position sensors for the wheels (can determine tank position to within 6 mm; and surprisingly accurate for something made of slippery plastic 
— to play with & they can all be mounted on the unit simultaneously.
The AX-11 board is pretty impressive — apart from being constructed with all discrete components and also being a plastic box screwed together (have already stripped one of the threads getting into the battery compartment).
The controller has dozens of digital and analog inputs, an in-built IR transmitter and receiver (sending 8-bit bytes, apparently), an RS232 port, special dual inputs for sonars, 6 servo ports, 4 motor ports (both clockwise and anti-clockwise control provided for each), and a small LCD.
The massive (2 kg) weight of the package was mostly due to the 9.6V worth of NiCds that were provided by the manufacturer. I had heard that was a non-non for international shipping. But it did come from HK, so I guess that explains that.
The 68xx-based board has a "test" mode that enables sensors and servos to be tested. Quite neat to hook up some random IR sensors and see what they return.
There are many strange things about the kit. It isn’t listed as a product on Inex’s web page. There are 2 copies of the manual on the CD — 90% similar but with some intriguing differences. They seem to have supplied about twice the number of plastic parts you can actually use. And some of the plastic parts don’t seem to mesh with the others (i.e. in terms of hole diameters or thicknesses).
And the tractor treads were supplied in various odd-sized lengths that had to be labouriously connected. Luckily I’d built a toy tank model as a kid — otherwise the tracks might still be lying there with me wondering how the hell do you fit THAT cow-horn through THAT little hole?
So far I’ve only down-loaded some example programs from the CD. And made a hack or 2 — who can resist that?
The 3-linetracker follower worked fine. But I still haven’t written anything to calculate the area of the figure traced. On my to-do list.
And with all this talk about Eskis, I hacked up something to follow you around the room at a distance of 30 cm. Using the provided Sharp ranger and a bit of "swivel logic", the little tractor treads were tearing up the carpet (literally, in parts!).
Now all I need is a can-throwing kit.
After installing a new hi-tech web-cam, I’ve even managed to snaffle some pix. I obviously need more work on the picture-taking as well as which buttons to push on the processing side of things (I was using a low-res setting for the web, and the "auto-fix" things they have with JPEG tools seem to have interacted to turn my carpet from creamy brown to GREEN).
Here is Mr tank: 
Here is Mr Tank playing follow the thirsty man (shadow of head of thirsty man makes guest appearance): 
A bit of a close-up showing ranger (black oblong thing mounted centre front), touch sensors (the square yellow things) and the line-tracker connections (going underneath left & right at front):
Awesome! Maybe we should make that an official competition or something.
"Build a device that can successfully deliver a cold beverage from an eski to a specified target area. Extra points for opening it before delivery."
Now THAT’s an idea!
Maybe we need to start a "petit challenges" subject in the forums.
I like this idea.
I already have a RC Esky which zips around delivering beers and which is due to get upgraded to pc control, but I think a robot should be automated and not a RC model – as far as a competition goes. So my RC Esky wouldnt count as it stands. What do you guys think?
That robot wars thing is really Radio Controlled machines wars not robot wars? ?
Yeah Robot Wars is a bit of misnomer really. But then again, trying to work out exactly what is a robot and what isn’t is worth a PHD in itself these days
Your RC eski sounds like a good platform to built automation onto though!
Gidday Ash,
The idea is to make a platform robust enough to keep a PC or laptop mobile. There seems to be no cheap off the shelf way to do this? ?
Hey, have you noticed that in general chicks dont dig machines?
For instance, every guy who hears about or sees the Teski (Tank Esky) wants one( theres a mpeg of it kickin around somewheres) and everyone says ‘COOL you should do this and this and this etc… with it’ – seriously I have never had so much enthusiastic feedback – but not from chicks - I took the Teski in to show my old boss – he was enthused but the 6 girls who work at the presses at that drycleaning shop all saw it and none of them said one word – until Mandulah the indian girl said ‘ Oh I can see why you dont have a girlfriend !!!! ‘
Peggy is an old trooper though and would drink anyone under the table and she wanted a teski - so not all women are the same I suppose.
Howz your electronics skills? I got sent some free samples from National Semiconductor. These were programmable micro-potentiometers. My plan was to find out what sort of pots my old RC transmitter unit uses and mirror them with pc controlled micropots – that way I could use my old rc unit handheld or computer controlled. But I never interfaced the chips - does anybody know if there is any reason why that sort of approach should not work?
dave
Hmm, my electronic skills are fine as long as you stay in the TTL digital world. It’s the analog stuff that kills me!
It probably wouldn’t be too hard to splice in those pots so that you can switch between them and the original controller. You could then just plug the controller into your comp (perhaps via a UBW or something similar) and then bobs your uncle! (or aunt – these ARE modern times
If your home computer is going to be around where your robot is you might want to think about offloading the processing via some sort of wireless link rather than trying to fit a lappy onto the actual machine. Depends what you are trying to do really.
Because I am interested in computer vision I like the idea of the robot just being a physical interface for the computer to explore my house
Also in the case of your Tesky (hehe cool name) it would then allow you to possibly use other sensors like cameras etc that are not even mounted on the robot itself. The digital pot idea sounds like a good straightforward way to easily switch between autonomous and manual control though.
Regarding girls and robots, luckily for me I work with a lot of girls who are unusually into robots and my girlfriend has come to understand (over the years) how much I am into them so she gets as excited as I do when my table full of servos and LEDs starts flashing and jiggling around
I would have to say the Transformers movie has also helped bridge the male/female/robot divide hehe
Thanks for the reply Ash. You ARE lucky to know girls into robotics!!! I honestly only know one and she lives in London. I think the Japanese girls really dig robots too, so I stand corrected.
As for setting a laptop up as the brain in a robot —- I will ask you one question - can u give a robot a better brain? And I reckon most robots are too small anyway!
……….. A couple of years ago I had a go at making the following robot for a party nite…..
———————————————————–
2*battery drill motors + Wheels + castor base….
2*12V lead acid batts…………………………………….
1*150Watt Inverter.(240V output)…………………..
2*Stereo speakers + AMP……………………………….
1* 100Mhz IBMThinkPad + wireless ethernet card …
1* Parallel Port dual H-bridge Motor drive………….
1* Strap on inflatable sex doll…………………………
——————————————————————
Using VB, I installed on the IBMThinkPad, a program that would output any text file, thru the speakers, as a sexy female computer voice !
From a second, desk based, computer I remotely controlled and sent text files to the mobile IBMThinkpad Dirty Mouthed Sexbot !!!!!
For example I created a text file with obscene comments about my mate Mat who was getting married – it was his Bucks Party.
Not only could I leave the IBMThinkpad robot to run its own on board programs, but I could also remotely control what was running on that Laptop robot or even drive it directly via my second wireless computer.
This robot was for my friend/boss in an IT department. It sure was a HOOT buying that doll
The Laptop was able to remain in its charging/docking station which recieved 240V via the inverter. The inverter also powered the speakers/amp.
In normal operation the laptop was ON but had its screen folded down for the lowest possible profile - but the screen was invaluable when it came to interogate and program the robot.
……..that said ….. s i g h ………! !
It didnt work that well. The laptop had trouble keeping pace with synchronizing its pulses to the MOSFETS and speaking dirty at the same time. The result was erratic and unpredictable behaviour of the motors. It had me BAFFLED!! I tested all components as ok, but still this monster had trouble just doing what is said it was doing. The Laptops parallel port pins were not firing when the software said but would often delay unpredictably. I put this down to ‘interlacing’ issues of the multiple process operating system. windoze …….I HATE BILL!!
I reckon the purchase of a real motor driver card from a real manufacturer would have solved all my problems - oh,.. and a newer Laptop!!!
Oh well, onward christian robots!!!
p.s. have you seen those air soft tanks?? Id love to hack the RC transmitter and computer control one of those babies!!!!!!
Hehe, that sounds awesome!
I have to say, the appeal of the dirty-talking-sex-o-droid was probably only improved by the slightly out of control motors hehe
How long did the batteries last for? I’m definitely gonna have to buy a mini- or nano-itx board and use that as a brain one day. That way I could just plug in a normal webcam and wireless card and run the OS from flash for efficiency.
I am looking forward to getting into the competition a bit more as soon as I get a chance. I have been really busy at work this week (as you can tell from the fact that I am posting this from work at 11:38pm
but I’m definitely gonna try to get some more hardware for my beerdroid on Saturday.