Society of Robots - Robot Forum
General Misc => Misc => Topic started by: Caduscus on December 20, 2007, 12:18:10 PM
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Now i'm no expert, but i've read alot about electronics and mabye instead of a 70 $ Microcontroller, couldn't you just use a voltage comparator? I found on e at radioshack for like 2 $s this doesn't requuire programming, and it's way cheaper..but would it work? ???
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the mcu in the $50 robot doesnt cost $70 - its much ,much cheaper
You could use a voltage comparator to provide difference in voltage levels, you would need at least 2 do do what the microcontroller does.
A voltage comparator wont drive the servo's, You may be able to do it with some 555's connected to the voltage comparators (its even possible without the comparators)and a few extra resistors and caps, and trimpots for tuning but it would eventually be cheaper and simpler to go with the microcontroller
Also if you built the $50 robot with just hardware and no microcontroller, all it would ever be is a photovore - The microcontroller gives you the ability to upgrade and expand your robot as your knowledge grows
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what he said. the mcu costs under $5. depends where you buy it from.
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what he said. ;)
Sure you can build a robot with a comparator and some 555 timers... but then you can never change what it does (photovore).
With that cheap MCU you can make it do endless different tasks.
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Thnx for the help guys, so far i'm still in testing on a breadboard for this circuit, but i've using PNP transistor to power 2 DC motors from the comparators output, I got this idea from Robot Building for Beginners Which is how I learned all the stuff I know so far, and from you guys and other books...but anyway do I really need timers? i'm not even quite sure what they're for that much, and no I don't really need a microcontroller for my first bot, I want it to be a Photovore, i'm getting a BASIC Stamp microntroller kit thingy as soon as I get the money..lol it's like 80$ :-\
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I would get a regular PIC or AVR programmer for like 30 bucks and get the cheap MCUs themselves for like 2 bucks
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or spend $34 for a mcu and USB programmer (arduino ;D)
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Caduscus I for one am interested in your idea to make it without the use of an MCU. I want to see documentation posted on this forum ;)
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Caduscus I for one am interested in your idea to make it without the use of an MCU. I want to see documentation posted on this forum ;)
Why?
Its soooo simple to do!
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shut your pie hole! lol jk... I would just like to see and follow what a fellow roboticist is doing :)
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I would just like to see and follow what a fellow roboticist is doing :)
k :D
But seriously caduscus if you want to get into robotics use an MCU
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or spend $34 for a mcu and USB programmer (arduino ;D)
^ what he said, i have one and a sparkfun sheild kit, i love it!
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shut your pie hole! lol jk... I would just like to see and follow what a fellow roboticist is doing :)
Sure! I'm excited someone's interested in mmy *cough* "new" approch, you want schematics or what? i'm not sure what you mean by Documnetation... ???
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Schematics and just general notes if any, ya know. that kinda thing, pics too if ya got em :D
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Alright,i'm nearly done, i'll post some pictures of my handiwork in a while, I've got the positive and GND buses sorted out and the power to the IC socket pics are coming soon! :D
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yay for a schematic fresh from the brain get it while it's hot! ;D
(http://[URL=http://img107.imageshack.us/my.php?image=comparatorschematichn3.png][IMG]http://img107.imageshack.us/img107/6438/comparatorschematichn3.th.png)[/URL][/img]
It's just a little modded(alot modded) form of my old schematic I drew up to show someone and for my own refrence, I chopped a few wires and wrote the GND symbol and added a trimmer in there for kicks. hav at it
more coming soon
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yay for a schematic fresh from the brain get it while it's hot! ;D
(http://[URL=http://img107.imageshack.us/my.php?image=comparatorschematichn3.png][IMG]http://img107.imageshack.us/img107/6438/comparatorschematichn3.th.png)[/URL][/img]
It's just a little modded(alot modded) form of my old schematic I drew up to show someone and for my own refrence, I chopped a few wires and wrote the GND symbol and added a trimmer in there for kicks. hav at it
more coming soon
umm pic dont work
heres a direct link. it works
http://img107.imageshack.us/my.php?image=comparatorschematichn3.png
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You do realise that this circuit works for motors but not servo's dont you?
I just dont want you wasting your money.
Also if you use any decent powered motors you will have to add extra circuitry
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okay, sry about that it's always embarrassing when your schematic shwios the stupid little X symbol ::)
anywho yeah i'm going to post some working pictures and yes I do realise this owuldn't work with servos,
I got some cheap(and crappy) DC motors from adioshack,
rated at 1.5-3 volts, and i'm using a 9V battery, is this safe ? will the electronics eat up enough energy so the mottors don't override?
and how will little jimmy get out of the well?
oh god the suspense is killing me! :P
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those motors from radio shack will spin very fast with vey little torue. you need a gear drive to reduce the speed and increase the torque. IIRC the VCR robot tutorial showed how to do that
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A thought of mine . . .
I know most people don't want to use a microcontroller for one reason:
They are scary.
I mean that they look really hard, and beginners are really scared to use them for that reason alone.
But if you copy someone's design and code (such as my $50 Robot), its actually much easier than you think. And in the long term you would be much happier with them.
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yea im scared to use em.......i may at a later stage but for now i like the $40 robot ;D
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sounds like a challenge project. What is the cheapest (street value) that you can build an autonomous robot? Some function is necessary, such as object avoidance, tracking, line following etc. Every part value must be as purchased new. No free wire, free tape, free motors etc. Part numbers would be great too. Tools don't count, and the simplest of circuits should be a goal. Perhaps a $5 light chasing robot, with cardboard wheels. Something super cheap, super easy for a first bot for newbies.
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my $40 robot costs $58 australian all up...everything. apart from soldering iron and solder/tools used. im building it now.
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my $40 robot costs $58 australian all up...everything. apart from soldering iron and solder/tools used. im building it now.
didn't you say you finished it and won a competition , like a week ago?
cheapest for an autonomous robot technically is a solar panel and an LED. The LED turns on only when there is light present, there autonomy!
A robot that moves would probably be under 10 dollars , a basic light detector with differential drive and scotch tape
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The point of the challenge I mention, is so somebody can follow a guide to build their own. Just like the $50 bot, but much cheaper. Something that will allow just about anybody to build one. parts off the shelf from radio shack (so my 10 y/o wont need to place an order on digikey, because he's not getting my credit card!).
Something that can help feed that inspiration when you are first bitten by the bug. Which means it needs to be somewhat cool, educational, a good foundation, and entertaining. Something that will impress the grandparent when they come over. I love the idea of the $50 robot, but $50 is alot for younger people to afford for something they are just curious about. $5 with free plans it going to be much easier to get started with. If we're expandable (not sacrificed for parts), or interactive that would be even better. eg. 2 bots using ir send / receive that chase each other down in a game of tag. At $5 or even $10 each, you could get a couple of these or more, win the science fair, and be entertained, not to mention hooked on robotics.
Not everyone is going to agree, but $50 is just to much for some to get started with. Add in the price of a programmer, and it's even higher.
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Hey Ive been working with my business advisor for the past few days in order to develop a robotics business. One of the first products that I intend to provide is something similar to what you want, A very cheap entry level device. I'm in the stage of making sure that my electonic circuits arent going to step on anybodys patents. Although this design will be finished very shortly I wont be releasing it until I have a range of whole products which can produce a satisfactory turnover. This kit will be a custom designed pcb with necessarry components provided in the box with building instructions The only thing you would need is a soldering iron and solder (unless otherwise stated ;D).
I am planning on producing eductional style robots with at least 1 robot for each 1 robot planned for each age group/education level
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that sounds great. what sort of price range?
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Im trying to keep the price somewhere around or below if possible $12.50
The main cost is for circuit boards, chassis and motors so Im putting in a lot of hours tracking down the most cost friendly manufacturers and fabbing houses
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That's more what I'm talking about. $12 is a great start in the right direction.