About to begin robotics

whiteoxe

Hi, I have spent a couple of days rtrying to find a robot that I could afford esp;ecially as its all new to me. The parfallex robots were out of my reach just now so i looked at something cheasper to begin with.
There was the Bot 120 from Spark fun powered by the brains of a picaxe chip. Since Ive made several projects using the picaxe and that irts programmed in basic i very nearly bout it for $75 dollars.

There were a few others but the price was always out of my reach. I settled on a robot that used a rasberry PI because I had one not being used. I had to purchase a chassis to give it movment and a robotboard for it as well. The cost was only $45 dollars + $30 IF I COUNT THE RASBERRY PI THAT WAS NOT BEING USED.

Magician Chassis
Out of stock ROB-10825
$14.95
RaspiRobot Board
Only 10 left! KIT-11561
$29.95


I could have bought the bot 1q20 with the picaxe brain for the same amount. I hope i dont end up regretting it but the robot im putting together can be progtrammed using python which im only just learning. I have searched the internet for code rthat learns. You give the robot a job to do but the code doesent contain routines that solve the problem , it is code that allows the robot to learn and try to decide the best course of action on its own.

Is this becoming the standard way for hobbyists to try and program there robots ?

Waht sort of things have you been able to make your own robots do ?

Thankyou, Mike.

bomber

I am surprised that you are incorporating Machine Learning into your robot, It certainly is becoming more common for microcontrollers to be secondary processors and the main processor being a SoC or an ATX-style computng system. A great example is Parallax's Eddie Robot (now retired) (http://www.parallax.com/product/28992), which is designed for a laptop to be mounted on. I am also using Python to program my Eddie robot, and the only issue I have been running into is that it is VERY difficult to get multitasking working in Python. Python's interpeter uses something called GIL or Global Interpeter Lock, so it can only execute one command at a time per interpreter running. My current python program uses two interpeters running in parallel and passing data back and forth using a shared location in system RAM (since there is no 'easy' way to share large amounts of data between interpeters). It is tasked with interfacing with the Kinect sensor's SDK, preforming basic image processing, receiving input from an Xbox joystick for control, and sending serial commands to the secondary (Propeller) processor which drives the actual robot hardware. There is also a full GUI and the actual functionality of the program, which lets you drive Eddie like a very expensive (and power hungry) RC car, and using the Skeleton Tracking feature of the Kinect SDK, get an x,y,and z location of a person's body in 3D space, and move the robot so the person being tracked is always in the center of the screen (essentially so it follows you around). I also have a GPS reciever on Eddie, combined with the Google Maps API to eventually have Eddie following GPS navigation, so i tell it a set of coordinates and it (tries) to navigate there (this would have to be for very short distances, like less than 100 feet or so). Anyways, good luck with your robotic adventures, and the machine learning code that you intend to implement sounds really interesting if you can get it working!

erco

Ouch. Pity you didn't ask first. The Magician chassis is a poor choice for numerous reasons, primarily the DC gearmotors provided are undergeared, mismatched, too fast, squirrely, and difficult to use. IMO a BoeBot is best for a beginner. Proven and well-documented with tons of free educational material available. You can find them used on Ebay for $70 occasionally. Scribbler 1 is next best, more work to hack, but reliable and ready to go. I have bought several of those used for $20-25. A used Parallax bot is far superior to a new Magician.

erco

Mike (aka rigidigital): Is this also you?

http://www.picaxeforum.co.uk/showthread.php?25836-Starting-Robots

whiteoxe

erco wrote: »

Mike (aka rigidigital): Is this also you?

http://www.picaxeforum.co.uk/showthread.php?25836-Starting-Robots

yes, that is me ?.. I wish i jad checked back at this forum because i missed so many good replies. I want the boebot or the scribbler !!!! Alas Ive just used the credit card to buy the package Magician Chassis
Out of stock ROB-10825
$14.95
RaspiRobot Board
Only 10 left! KIT-11561
$29.95

However as the magic is out of stock (even though i paid for it) if i write a convincing email there may be a slight chance i can cancel the order. Ill try and post you the result

whiteoxe

erco wrote: »

Ouch. Pity you didn't ask first. The Magician chassis is a poor choice for numerous reasons, primarily the DC gearmotors provided are undergeared, mismatched, too fast, squirrely, and difficult to use. IMO a BoeBot is best for a beginner. Proven and well-documented with tons of free educational material available. You can find them used on Ebay for $70 occasionally. Scribbler 1 is next best, more work to hack, but reliable and ready to go. I have bought several of those used for $20-25. A used Parallax bot is far superior to a new Magician.

Ecro, the seconhand bots you speak of can be powered by basic stamps or the prop ..true ?

Just out of curiosity, what do you think of the Lego mind storm as a robot ?

Publison

whiteoxe wrote: »

Ecro, the seconhand bots you speak of can be powered by basic stamps or the prop ..true ?

The original (blue) scribbler and the BOE-BOT both include the BS2 chip. The new Scribbler (red) has a Propeller on board.

I agree with erco. The BoeBot would be the best to go with for learning.

whiteoxe

I am waiting to hear if my request to cancel my order of the robot part i order is accepted. . as half of it was out of stock i think my chances are pretty good. Bu5t if the sale goes ahead i will make the best of it.

If i do end up getting the Boe Bot and its prop powered, I hop[e i find some interesting code in the obex. Perhaps there might even be some code that helps the robot to Learn , rather than just follow code line by line ? Here an idea off the top of my head at 2.38 in the morning The robot is programed to like the tuna in the little dish on the kitchen floor. Its happy just to stand beside it. If another little bowl of tuna is places near by the robot it might decide to go and stand by it or it might roll back and forth between the two thinking twice as much is a good idea. Or it might just ignore the second bowl. But if it went back and forwards between the two bowl because it liked them both and it learns that there were two bowls it liked and then you took one away it would be fun to see it start looking around the kitchen floor to try and find it. But then if it liked thje little bowl of tuna it might just go back to the bowl that was still there and not bother looking for the one that vanished.

GordonMcComb

Agree with Erco -- the Magician chassis is a poor product. Or I should say the motors used on it aren't good for the application. The acrylic body pieces, ball caster, and rubber wheels are fine!

Try eBay for a used BOE Bot. Keep your eye out for a deal -- you can often find something in the $50 range, especially now as school is getting out.

There's nothing wrong with LEGO bots, but they're no less expensive than anything you'd cobble together. You'll learn more with a BOE Bot or system you put together. Stick with a robot that uses servo motors; you won't need motor bridges that way.

The PICAXE is a fine chip and all you really need for your first bot is an 08M2 ($3), download cable, a mini breadboard, some jumper wires, long 3-pin headers (to more easily connect your servo motors to the breadboard) and a small assortment of resistors. Total cost for these parts shouldn't be more than $10.

Anyway, there are always ways to do it on the cheap, but there's a greater chance of failure when you put everything together yourself. The world is full of robot first-timers that turned out to be only-timers. If you can save up a little bit more, my preferred choice would be a used BOE Bot chassis with a Parallax Activity Board.

Duane Degn

I doubt it will surprise anyone when I recommend using a Propeller as the robot controller. The Propeller's ability to monitor multiple sensors and control multiple devices at once makes it a great microcontroller to use with robots.

I have a thread about making an inexpensive robot. It doesn't take much money to start learning about robotics.

If you do decide to use the Propeller (and you'd be nuts not to), I have a list of links to Propeller tutorials in post #3 of my index (see signature). While you're there (in the index), you ought to check out some of the projects listed in post #2. I'm not positive all the projects use a Propeller, but I'd be surprised if any of the listed projects don't include one. There's a Scribbler 2 project on the list, there's also a BOE-Bot on the list. The BOE-Bot isn't a BS2 version it's a PropBOE-Bot.

If you're looking for a ready made kit, I'd suggest the Activity Bot (though I think I'd still use Spin to program it) or the Scribbler 2.

Publison

whiteoxe wrote: »

If i do end up getting the Boe Bot and its prop powered,

The standard BoeBot is BS2 powered. There is a new Bot that is propeller powered:

http://www.parallax.com/product/32500

Might be hard to find used as it is kinda new.

Duane Degn

whiteoxe wrote: »

If i do end up getting the Boe Bot and its prop powered, I hop[e i find some interesting code in the obex.

Sorry, I missed posts #8 and #9 while I was typing #10.

While my PropBOE-Bot didn't learn to like tuna, it could remember the course it took while under remote control.

And sure a robot can learn. As long as the line by line code tells it to do so.

Duane Degn

Publison wrote: »

The standard BoeBot is BS2 powered. There is a new Bot that is propeller powered:

http://www.parallax.com/product/32500

Might be hard to find used as it is kinda new.

Lots of the Propeller boards Parallax sells will fit on the BOE-Bot just fine. Off the top of my head I can think of the Propeller Proto Board, Project Board, PropBOE, and Activity Board.

My first Propeller powered BOE-Bot used an upside down Proto Board. I attached a breadboard to the back of the Proto Board and used female headers to bring all the IO pins up around the breadboard.

This upside down Proto Board is now used to control my omni-bot. (Make sure and check out the "OmnibotSpinningStraight" video.)

erco

Potentially cheap Boebot on Ebay:

http://www.ebay.com/itm/ROBOTICS-BOE-BOT-ROBOT-MODEL-KIT-/171307713413?pt=LH_DefaultDomain_0&hash=item27e2bc4385

Genetix

The Boe-Bot s very easy to program since it's Microcontroller uses BASIC. There are also a number of attachments that you can get if you want more than a standard Boe-Bot.
If you decide to switch to the Propeller then all you need to do is take the Board of Education off the Boe-Bot and replace it with a Propeller Activity Board. There are instructions and code on the Learn website on how to do this.

The Boe-Bot manual has instructions on how to assemble and program it. You should first read What's a Microcontroller, which can be downloaded from the Parallax website before you stat with the Boe-Bot text. What's a Microcontroller (WAM) will show you how to use and program the BASIC Stamp 2, which is the Microcontroller the Boe-Bot uses.

If you have any questions you can always post them here and someone will help you out. Good luck on Ebay.

whiteoxe

erco wrote: »

Ouch. Pity you didn't ask first. The Magician chassis is a poor choice for numerous reasons, primarily the DC gearmotors provided are undergeared, mismatched, too fast, squirrely, and difficult to use. IMO a BoeBot is best for a beginner. Proven and well-documented with tons of free educational material available. You can find them used on Ebay for $70 occasionally. Scribbler 1 is next best, more work to hack, but reliable and ready to go. I have bought several of those used for $20-25. A used Parallax bot is far superior to a new Magician.

Thanks for the tip about the Magician, I was able to cancel the order. They told me there should be as new improved chassis in several weeks, I think they didn't think too highly of it either Ive had a pretty interesting time finding many varieties of robots. Even went to Alibaba site where there was an overwhelming variety, some quite expensive and you don't seem to be able to order a quantity of 1. (but i did order 1 truck Weighbridge for $15,000 for an uncle, the cheapest in Australia was over $30,000 and the company is going to send over a man to help install at a weekly rate Aussies wouldn't accept)..sorry off track now... just saying that site can be good.

.Some of the robots about a foot in height were very high end looking with many types of sensors and servo motors, no price, you had to ask and if i have to ask, I'd think i can't afford it ! There were multiple sellers of the lego MindStorm which can be programmed in its own graphical way or MS Robots C# and other methods. I found it curious the prices were around $150 yet ebay and other places want over $400 ?? but I'm sure you have too buy a fair number as the site is wholesale.

So I have taken your advice and bought a Scribbler with a basic stamp microcontroller. It cost me only $20 like you thought. It looks like such a tight, closed case for anything i might want to add on, but i guess I'll see what is possible soon. Ive never used a basic stamp so im downloading the manual and will have a pretty reasonable idea by the time it arrives.

The boe bot you linked to was looking reasonable even with freight cost but since I bought the scribbler at such a low price i dont want to get into a potential bidding war. This all started out because i had a rasberry Pi and wanted to do something with it. Well I'll just hang on to that for the moment. And anyway the robots Ive noticed on searching the Pi seem to always have another microcontroller as part of the setup, a picaxe or an arduino> It was not easy to search for robot building without running into Arduino.... So Im happy getting the scribbler to make a start. Ive got a few general questions but i'll ask in the general forum. Thanks everyone who wrote a response to my post.
regards,
Mike.

Genetix

Congratulations on scoring a Scribbler but don't miss the opportunity on the Boe-Bot.
Playing with a Scribbler can be fun but a Boe-Bot is customizable with over a dozen add-ons.

Some of the people on the Forum also use other products such as the Raspberry Pi so someone might know what to do with it or might trade it for something else.
The BASIC Stamp has been around for years so there are many nice books on it.
If you download the BASIC Stamp Editor, What's a Microcontroller and the Stamp Reference Manual are both inside. Many of the WAM activities can be done with the Boe-Bot parts.
Robotics is just one of the areas that the BASIC Stamp is used.

erco

Great score for $20, whiteoxe. A Scribbler is perfect to jump into robotics and learn BS2 programming. Lots of sensors to keep you busy for a while, then when you're ready to hack it you can open the case and do your own thing. At $20, you can cut a few holes in the body and splice into a few wires without worrying too much. Keep the IR LEDs & receiver & speaker as-is. The "hacker port" gives you access to the 3 I/O pins to the red LEDs. IMO the 3 light sensors are the least useful and thus, first to go. You may or may not want to keep the line sensors.

Plenty of info out there and in the forum. Hopefully you get all the documentation with your bot. See info.hobbyengineering.com/specs/PX-ScribblerHackHint.pdf

Here's an article I wrote: http://www.botmag.com/index.php/take-charge-of-your-scribbler-robots-ir-capabilities

whiteoxe

Thx Erco and Genetix for the positive spin, i mean encouragement! Im smiling so much reading "when you're ready to hack it you can open the case and do your own thing" When I first started writing to this forum I was buying cheap electronic kits from Jcar, teaching how resistors, capacitors , leds, buzzers , switching on relays with a tiny current etc. I pretended I was buying them for a child, till one day the nice bloke at the store said " your buying these for yourself arnt you ? " to which i admitted my guilt, but he thought it was great so i lost that feeling of being backwards or whatever it was that made me want to appear differently

This question is way premature but i'll ask anyway. How do you make the robot LIKE doing something . a very simple way would be to increase a value and have it repeat the action until it reaches any arbitrary value you have assigned. but that's just following a loop that's pretty fake . There would be some kind of reward algorithm that's not complex that would be better than that ?

Duane Degn

Someone here one the forum had a BS2 program for a robot which used, what the programmer called, "pain". The robot had multiple sensors. I think they were primarily IR proximity sensors and then bumper sensors. The code would keep track of the non-bump sensors and when a bump sensor was activated, the sensor conditions just prior to the bump were considered pain. After bumping into things a few times, the robot soon learned not to take actions which would likely cause it pain.

I'll try to find a link to the project and post it here.

I thought it was a cool project but one downside to his approach was the need for redundant sensors.The non-contact obstacle sensors had to have a corresponding bump sensor for the robot to make good use of the non-contact sensor.

Let's face it, no matter what sort of algorithm one comes up with for a robot to feel "pain", the algorithm will be "pretty fake".

Genetix

I am not familiar with the Scribbler but every Boe-Bot behaves differently because no two Servos or Sensors are alike. I guess you can call that quirkiness or personality.
It's so much easier to adjust some software values then spend 2 or 3X more for higher quality components.

Duane Degn

I found the robot with a "pain" algorithm. Jim the Hermit made it. Here's the Parallax forum link. The link to the video in post #1 doesn't work but I did find the video here.

Jim has more information about the project on Let's Make Robots.

whiteoxe

Thx Duane . That sounds a lot better than the value counting scenario... using two sensors to figure out what to do just sounds interesting. Ive spent the morning working through http://www.learnpython.org/en/Functions . Im feeling I should switch to the Basic Stamp manual, but enjoying the python site too much at the moment, I'll check the links out now though, thx for finding that.

..........................................
That was great, I'll be trying out a version for the Scribbler , I though the led turning on when its Afraid was a funny trick ! maybe if i find another $20 Scribbler I could put them in a room together and soon see who was a brave or cowardly robot, taking note of what Genetix said about sensors being not perfectly uniform

erco

A cardboard Scribbler "robot" with a hardware Random function. http://www.ebay.com/itm/SpiderFish-SCR05-Scribbler-The-Drawing-Robot-Great-Science-Kit-For-Kids-/291003372661?pt=Educational_Toys_US&hash=item43c1271475

whiteoxe

i kina wish i was getting a prop brained robot. I was mediocre at that programming, but basic stamp will be new. but its fine to start with. and for $20 + a few bucks postage ill find out if i enjoy robots real cheap.

erco

whiteoxe wrote: »

i kina wish i was getting a prop brained robot. I was mediocre at that programming, but basic stamp will be new. but its fine to start with. and for $20 + a few bucks postage ill find out if i enjoy robots real cheap.

Champagne tastes and a beer budget. For your $20, your S1 will keep you busy for a bit while you save up for an Activity Bot.

Duane Degn

erco wrote: »

while you save up for an Activity Bot.

The first link in post #10 leads to thread on how to make an inexpensive Propeller robot. One could get a Propeller robot up and running for about $50.

whiteoxe

Duane Degn wrote: »

The first link in post #10 leads to thread on how to make an inexpensive Propeller robot. One could get a Propeller robot up and running for about $50.

Avery excellent resource ,thank you for showing it to me. That looks like the way i will go next , probably sooner than i even think. Because i do have Champlain tastes on a light beer budget !

I didnt think my local electronics store had robots but they do from going to their website. Even a simple platform with wheels is dirt cheap however your ideas may make that unnecessary.

whiteoxe

Just for some extra info incase someone has a champagne budget I did see robots on Alibaba that were humanoid looking, 30cm tall with a lot of servos for arms legs head, its programmed in C and its black, you'd think a prop would be perfect for that many servos. Any way i think the asking price was $700 so we are talking French champagne !

Duane Degn

whiteoxe wrote: »

think a prop would be perfect for that many servos.

I'm glad to see you thinking straight.

With some extra IC chips the Prop should be able to control 144 servos (with a single cog).

whiteoxe

I admit even though i looked at the Pain code for the BS2, i was getting lost because i haven't read the basic stamp manual; and only just starting on whats a micro controller. But it makes me wonder why if IR can sense distance to a wall why does it need to bump into it anyway ? You Don't need to answer that, ill understand when i can read the BS2 code, its a lazy question, but this one i am curious, does the scribbler keep track of wheel rotations ?

The guy, he was going to let me know Monday the postage , it wont be much because hes only a few hundred miles away in Australia has still not got back to me, ill just keep waiting.