Author Topic: I would really like to get started in Robotics (Read 19129 times)

center · « **on:** March 05, 2006, 04:53:03 PM »

So after reading your site I really became fascinated at what a simple creation can do and how it can think on its own.

So i have been looking around and found some places to buy some equipment.
if i bought the cerebellum microcontrol on botrics.
Bought one NiMH battery.
Bought 10 (although i think i would use 2 for starters) photoresistors on EBay
http://cgi.ebay.com/Lot-of-10x-photoresistors-and-10x-phototransistors_W0QQitemZ7594606470QQcategoryZ67002QQssPageNameZWDVWQQrdZ1QQcmdZViewItem
And then used some of my Tamiya electronic engines that i took from these tiny cars.

Would i be able to plug everything together on a chassis that i made myself, and have it work?
Of course after i programmed it. Because someone on your site said that the cerebellum microcontrollers can be linked to a computer and then programmed with software on a windows based computer...
If this software does exist, is it easy to use? Do i need to know "C" programing language?

-Steve

If you need to see a picture of the motor, my older brother will be back with my camera later.

Thanks

zamboniman60 · « **Reply #1 on:** March 05, 2006, 10:56:21 PM »

HIGHLY recommend getting a basic microcontroller; way easier to get started with.

Admin · « **Reply #2 on:** March 06, 2006, 09:12:24 AM »

Yeap it is as easy as it sounds. Just dont forget to consider how to connect your motors to your frame, and your wheels to the motors. I forgot that on my first robot, and it kept breaking =P

If you use the cerebellum microcontroller, you would need to know how to program in C. The cerebellum has tons of sample code, but can be overwhelming for a beginning programmer. BASIC, being the easiest language in my opinion . . . you may want to start with one of those controllers first. I suggest getting a cheap one for you to start with, because in the future as you get better, PIC based controllers have much more features. Whatever looks easiest is best. Start easy and you can always upgrade later.

As for photoresistors, they cost like 20 cents or so each. I havnt checked, but radio shack may have them super cheap. Also try solarbotics.com.

http://www.solarbotics.com/products/index.php?scdfa-250100084-viewDetail-productzq3820zq4categoryzq33=true

center · « **Reply #3 on:** March 06, 2006, 10:47:35 AM »

so if what is the difference between a cerebellum and a basic stamp microcontroller

is this a stamp microcontroller?

if so, were do i hook up my various I/O components, and how do you program it?

center · « **Reply #4 on:** March 06, 2006, 10:48:34 AM »

I found that microcontroller at
http://www.hobbyengineering.com/H1428.html

center · « **Reply #5 on:** March 06, 2006, 10:53:07 AM »

At this website here i found a tutorial on how to build a robot for under $50 dollars.
The setup excludes any type of microcontroller, and uses a computer and a transmiter to send data back and forth over a wireless network, also incorporating a video cam, speakers, and a mic.
Please elaborate on this because it sounds like a great summer project. And how would i make everything work through the computer? Would i need to design a program? Or are there ones on the web?
If you do decide to help me out, the page is poorly written and if you could please list all of the parts that i have to buy that would be greatly appreciated.

Admin · « **Reply #6 on:** March 06, 2006, 11:03:41 AM »

You have read this, right?
http://www.societyofrobots.com/microcontroller_tutorial.shtml

Yeap, that image is a stamp.

What you are confused on is the difference between an augmented microcontroller and just a microcontroller alone.

A microcontroller actually needs a bunch of supporting electronics for various things. You will need things like on/off switchs, plugs for batteries, pins to connect your sensors, buttons for whatever, fuses, timing crystals, a motor driver, heat sinks for your motor driver, special stuff for serial connections to your computer, LED's, etc. The list can get quite big. The cerebellum, or any augmented microcontroller, has all that extra stuff done for you.

There are also different types of microcontrollers, including BASIC Stamps, PICs, and Atmels. They all require different methods, and sometimes different languages, to program them. On that microcontroller page, the top image has a small black square in the center. That is the PIC based microcontroller. Everything else is augmentation. The makers of these augmented microcontrollers supply manuals that tell you how to use them, so I wont go into detail for that.

As for that tutorial you found, what you say it says is possible, but if it doesnt tell you how to do it, I wouldnt recommend it.

The general rule of thumb for a beginner is, whatever is easier to learn and do, is better.

center · « **Reply #7 on:** March 06, 2006, 04:12:11 PM »

Today i was surfing the net looking for more ideas and i came accross this....

This looks a lot easier to make and utilizes the stamp microcontroller...since this is bought as a kit do you think it has been pre-programed?

center · « **Reply #8 on:** March 06, 2006, 05:54:55 PM »

Quick question....

what type of controller is this

http://www.pololu.com/products/pololu/0125/

Because it looks like a great way to get started....what do you think?

center · « **Reply #9 on:** March 06, 2006, 05:57:10 PM »

With the pololu would i need to buy a handheld programmer or does it need to be hooked up to a computer?

Admin · « **Reply #10 on:** March 06, 2006, 07:04:42 PM »

Referring to the robot they found, nope, they do not preprogram anything.

The pololu orangutan microcontroller is Atmel based.
read my posts about it here:
http://www.societyofrobots.com/robotforum/index.php?topic=5.0

I stopped using the pololu because there were too many bugs in the last version of WinAVR (software for compiling a program for it). A new version has recently been released but I havnt tried it. I think the cerebellum is better.

You would need to buy a programmer for the pololu AND hook it up to the computer.

zamboniman60 · « **Reply #11 on:** March 07, 2006, 07:17:27 PM »

If you get a PBASIC stamp buy direct from parallax (http://www.parallax.com), middlemen make things more expensive. Plus, parallax has sensors designed for the basic stamp.

center · « **Reply #12 on:** March 08, 2006, 07:28:22 AM »

For some reason this all still feels way to complicated.
If you could please make a list of everything that i would need to buy then i think i would be much better off.
Right now there are so many part numbers and names on your tutorials i have no idea if it is optional or not.
Like the MOSFETS to run the motor, and the likes.
All i want to create for my simplle beginner robot is a Photovore.
Once i get everything linked together on my chassis programming shouldn't be a problem.
I need to know what parts can go together, so if you maybe have a previous setup that you know worked and stayed in the $100-200 range then that would work also. If you could include part names or numbers it would help.
If you could do this it would be greatly appreciated.
Thank you

Admin · « **Reply #13 on:** March 08, 2006, 08:20:38 AM »

A detailed list really isn't possible. Instead, I will give you a basics list. Then you must find your own parts. After you have found each, and are sure it is want you want and can afford, come back and check with us. I wrote my tutorials not as a way to hold your hand and tell you exactly how to build a robot, but to instead guide you in the right direction and tell you what needs to be done, things to watch out for, and tricks you can do. The rest is up to you.

use my parts list to find everything:
http://www.societyofrobots.com/robot_parts_list.shtml

list:
Microcontroller (augmented, such as the cerebellum)
Motor driver (some microcontrollers already come with it, check)
serial cable (to program with your computer, some mic. come with it)
motors or servos
wheels
material for your robot frame, screws, plastic, velcro, metal, etc.
sensors, such as photoresistor
battery, and charger
programming software (refer to microcontroller manual for what you need)

Admin · « **Reply #14 on:** March 08, 2006, 08:24:20 AM »

hmmm I have been thinking about it . . . that perhaps my
http://www.societyofrobots.com/robot_tutorial.shtml
tutorial is still a little confusing and overwhelming.

when i get the time, im going to redo a lot of it, based on where your confusion is. i think others might have the same problem.

will probably take up to two weeks though . . .

center · « **Reply #15 on:** March 08, 2006, 10:44:18 AM »

your tutorial is great i just needed some extra help..
Thank you for taking the time to make it....
It has guided me in the right direction.

center · « **Reply #16 on:** March 08, 2006, 07:06:07 PM »

So a compiled a spreadsheet of what i have set up and to see if you think it will run or there are better parts that i can use.

Microcontroller: Using the cerebellum
Motor driver: (comes on the cerebellum already)
Serial cable:buying a converter to USB, i don't have any serial ports on my computer
Motors: I have two motors from my little tamiya cars...they have no readings on them Voltage wise, but are fairly powerful
Battery: I bought one that comes with a NiMH battery and a Charger, but i dont know if it will hook up to the microcontroller, and i looked for other batteries but there were no chargers with female ends that matched
Wheels: The wheels are from one of your refered web site, ultralight too
Material: For the frame i think i will go to Home Depot and have them make a frame out of thin plexiglass
sensors: 5 (although i only need 2) from Radioshack, I couldn't find anything on your list, which i thought would have been better
Programming software:here is programing software on the Botrics website

If anything doesn't work for some reason or you recommend a different part
Please let me know
Thanks for all the help.

Admin · « **Reply #17 on:** March 09, 2006, 07:55:08 AM »

For the serial connection, I dont think there is any way to do it with usb. The cerebellum software opens up a port on your computer to upload the program onto the PIC. I could be wrong, I have never used usb for it before . . . does the manual say anything?

Chances are the motors you have will run fine on a ~6V battery.

For connectors . . . most of the batteries on servocity.com have the right female connector. The one in this picture will work:
http://www.servocity.com/html/6_0v_1700mah_nicad_battery.html
If your battery doesnt have the right connector, you can always splice some wires. The cerebellum comes with a DC adaptor for power, but it doesnt give out enough current to run your motors. You can always cut off the connector and attach that to your battery wires.

Homedepot is good for robot parts. I always love it when I ask them a question, and they are like "what are you making? maybe i can help." Then I say "a robot" followed by an awkward silence . . .

I think your list is quite complete and good. O and Consider what screws you will need before homedepot, will probably save you a few trips =P

Consider a rangefinder http://www.societyofrobots.com/sensors_sharpirrange.shtml as a sensor. They are actually easier to implement than photoresistors, but cost about $13. Just remember you need an extra resistor for a photoresistor circuit:
http://www.societyofrobots.com/schematics_photoresistor.shtml
~330ohm will probably work fine. You can probably rip one out of old electronics.

g'luck!

center · « **Reply #18 on:** March 09, 2006, 04:36:50 PM »

So with a photoresistor i need to add another resistor and with the range finder i can just add it on and program it from there?
Hmmm... But then when you program it, you need to include different ranges for turning around. Correct?

center · « **Reply #19 on:** March 09, 2006, 05:38:42 PM »

What have you heard about the CMU CAMS.....easy to program as well?

zamboniman60 · « **Reply #20 on:** March 09, 2006, 09:49:18 PM »

heard they're really buggy

Admin · « **Reply #21 on:** March 10, 2006, 10:56:44 AM »

Correct.

Programming them are about equal difficulty.

Perhaps you can try both on your robot? The program for both are very similar . . .

Quote from: center on March 09, 2006, 04:36:50 PM

So with a photoresistor i need to add another resistor and with the range finder i can just add it on and program it from there?
Hmmm... But then when you program it, you need to include different ranges for turning around. Correct?

Admin · « **Reply #22 on:** March 10, 2006, 11:03:22 AM »

Ive used the CMUcam on several robots . . . Despite my sucess with them, I highly recommend against it. I understand computer vision really well, but interfacing these are just really frustrating, difficult, and buggy. I do have my old program for it to use with the cerebellum, but its really messy written so I never put it on this site.

I have not however used the more expensive CMUcam2, perhaps programming with them are easier/better, I dont know.

Quote from: center on March 09, 2006, 05:38:42 PM

What have you heard about the CMU CAMS.....easy to program as well?

center · « **Reply #23 on:** March 10, 2006, 02:59:55 PM »

Well then it sounds like iv'e got a green light...
I will possibly request some grants, i was thinking Northrop Grumman, (any others you know).
And there is a robotics club at GMU a local university and, i could get some help there for troubleshooting.
They know what they're are talking about, each year they get a $90,000 dollar grant to build (imagine that).
Well thanks for all the help, i will post pictures when all is complete.
Thanks
-Steve

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Author Topic: I would really like to get started in Robotics (Read 19129 times)