Author Topic: I want to make a PC-bot (Read 16197 times)

JumpJet · « **on:** October 01, 2007, 04:50:09 PM »

what i want to do is hook my laptop to a robot chassis and us it to take "live" control of the robot.
However i know little about electronics (i can sodder!) almost no programming.

If anyone could help, i would be very grateful!

creedcradle · « **Reply #1 on:** October 01, 2007, 05:02:47 PM »

if that is the case then to control the robot you can use the following

1. Parallel port- you can use Visual basic or C to program it and control the bot- you cant escape programming here

2. serial port - (RS232) - still visual basic or C language can be used

3. to make it harder use USB control - this is the most complicated among the three, you will have complex circuitry

but as a beginner try to use parallel port
controls

on the electronics side:

1. you have to know the parallel port configuration ; use google or wikipedia

hope these helps

JumpJet · « **Reply #2 on:** October 01, 2007, 05:10:45 PM »

If i used a USB to serial converter would i still have to program in the USB langauge?

Also what kind of circuit would i have to use for the motors and IR rangefinder?

creedcradle · « **Reply #3 on:** October 01, 2007, 05:16:48 PM »

Quote from: JumpJet on October 01, 2007, 05:10:45 PM

If i used a USB to serial converter would i still have to program in the USB langauge?

laptop-usb-serial-robot --> then your pc will program the usb and your robot will be programmed using serial communication [say a microcontroller]

Quote from: JumpJet on October 01, 2007, 05:10:45 PM

Also what kind of circuit would i have to use for the motors and IR rangefinder?

Admin has a tutorial for IR range finder; on the main page of SoR

JumpJet · « **Reply #4 on:** October 01, 2007, 05:18:10 PM »

thanks, but will this give me live control?

airman00 · « **Reply #5 on:** October 01, 2007, 05:28:55 PM »

hey jumpjet if you want ez control use Phidgets.
check my blog of my pc-bot at erobots.blogspot.com

Sorry about not putting any videos or pics, im just so busy for a competition with another robot

JumpJet · « **Reply #6 on:** October 01, 2007, 05:36:42 PM »

thanks, but that is a little out of my price range. Is there anything similar that costs less?

PS
your chives v2 looks like what i want to make.

airman00 · « **Reply #7 on:** October 01, 2007, 05:43:41 PM »

a phidget interface kit is only 70 bucks.

What is your price range, and what extra features do you want on your robot.

JumpJet · « **Reply #8 on:** October 01, 2007, 05:47:54 PM »

i am not very worried about features, so i want the base to cost about $50 (spent all my money on the laptop) if i am being impractical tell me

airman00 · « **Reply #9 on:** October 01, 2007, 05:50:46 PM »

if you want to do it el cheapo way then make your control come from a serial port or a parallel port.
Look what this guy did - http://ashishrd.blogspot.com/ and also check his other projects.

I recall that if you download roborealm ( a free machine vision software) google roborealm, you can directly control the serial and parallel port! the control is in one of the things on the side.

Also you got to think about what base you want. I used wheelchair motors( but only because sometimes I like to stand on chives and drive around with a joystick)

Provide a lot of details of exactly what you want your robot to do, approximate height, approximate weight, and budget.
Be here for another hour probably....
Keep em comin

JumpJet · « **Reply #10 on:** October 01, 2007, 05:55:43 PM »

what i really ment was i want to spend 50 just on electronics

PS
thanks for your help

airman00 · « **Reply #11 on:** October 01, 2007, 06:00:39 PM »

You want something like this: https://www.zagrosrobotics.com/shop/item.asp?itemid=523&catid=1

Basically look for the parts for this base.

Search around for 12Volt 20inlb torque motors. ( thats the major cost!) Make sure its DC so it can run off batteries!

You should wire the motors to your parallel port or serial port using relays ( details on my blog as well as a schematic) they are very cheap, probably less than 10 bucks for all the relays you need( 4 of them)

I would suggest you buy a cheap laptop on ebay and spend most of the money on parts, just make sure the laptop is XP or vista and has wifi..

Vista has excellent speech recognition which I use,

JumpJet · « **Reply #12 on:** October 01, 2007, 06:06:26 PM »

Duh! relays! of course! thank you!

airman00 · « **Reply #13 on:** October 01, 2007, 06:09:54 PM »

no problemo

post the motors you found and then one of us at the forum can tell you if there good for your needs.

As for relays I would check out AllElectronics.com I bought automotive relays AND their relay sockets for cheap from them. But those relays handle like 30 amps. First pick your batteries and motors, then your relays.

JumpJet · « **Reply #14 on:** October 01, 2007, 06:15:01 PM »

a DC gearhead wheelchair motor like the one you used sounds right for my purposes. is there any specific kind i should look for?

airman00 · « **Reply #15 on:** October 01, 2007, 06:19:41 PM »

wheelchair motors are overkill for what you want.....

if you decide to go with them, look what I wrote on my blog about using wheelchair motors

BUT BETTER YET
look what I found , exactly what you needed!
http://www.societyofrobots.com/robotforum/index.php?topic=1318.0

JumpJet · « **Reply #16 on:** October 01, 2007, 06:24:23 PM »

wow that IS perfect.

I used Google SketchUp to make this 3D model. The internal components will be smaller in real life so there will be more room and instead of a car battery I will use some DeWalt LiIon batterys.

creedcradle · « **Reply #17 on:** October 06, 2007, 06:57:33 PM »

Sketch observation:

it seems the angle with respect to the Y-axis is around 5 degrees,.. just make sure that your bot wont turn up side down when there is drastic change of speed, and also if you consider that your pc-bot would do a reverse direction then same thing may happen...

airman00 · « **Reply #18 on:** October 06, 2007, 07:02:38 PM »

nice sketch but i would suggest the motors and robot being mounted on a flat wooden base with caster coming from under it.

Also, a word of the wise. When buying the wiring buy different colors. Make your schematic and your robot color coded. If something fails you know what to do! Seperate modules from each other for easy fixing( by module I mean power controller, interface ,etc.)

Also, install a kill switch. Read what I wrote here. Even if you are not using wheelchair motors it applies to you !
http://www.societyofrobots.com/robotforum/index.php?topic=1904.0

Hope I helped,
Eric

Admin · « **Reply #19 on:** October 11, 2007, 06:50:21 PM »

Quote

Duh! relays! of course! thank you

just know that you can't directly drive relays with the serial port . . . I'd recommend something like this:
http://www.dimensionengineering.com/Sabertooth2X25.htm

(its too expensive for you, but it can accept serial commands)

Just google around . . .

airman00 · « **Reply #20 on:** October 11, 2007, 09:15:36 PM »

Unless you use a microcontroller to decode the serial output and give digital output to the relays, duh!

(or just use a parallel port to get digital output)

Hooray for relays!

Admin · « **Reply #21 on:** October 12, 2007, 04:33:45 AM »

Quote

Unless you use a microcontroller to decode the serial output and give digital output to the relays, duh!

lol, no. relays require much more power than a decoded serial output can give . . . you need to amplify it with a mosfet (the hard way) or motor driver

JumpJet · « **Reply #22 on:** October 12, 2007, 08:45:13 AM »

what if i use a parallel port? don't they give, like, 5 volts?

or what about this? http://www.pololu.com/products/pololu/0101/

airman00 · « **Reply #23 on:** October 12, 2007, 10:58:59 AM »

yes but you can have the parallel port switch a 5V relay which in turn switches 12V @ 5 amps!

The motor driver you posted looks good too but its for a microcontrollers serial port ( you might be able to use the computers serial port, but I personally do not know how)

Or use phidgets to control a relay which controls a motor( but you lose speed control by doing that)
check my blog for details or search google for phidgets ( only about $75 to buy)

Admin · « **Reply #24 on:** October 12, 2007, 11:36:15 AM »

Quote

don't they give, like, 5 volts?

relays require power, which is voltage times current (not just voltage). serial/parallel ports cannot give out enough current to power a relay. and if you try, dont blame me for a fried serial port

that pololu controller will work, but you will need an rs232 adaptor between your computer serial/usb port and the controller (I havent read the manual, but Im fairly sure of it). adaptors cost between $5 and $20. or you can make your own with a max232 IC and 4 caps.

JumpJet · « **Reply #25 on:** October 12, 2007, 12:05:55 PM »

ok, thanks.

I received my pololu USB to serial adapter and motor controller today. I installed the drivers, but where do I start with progarmming?

airman00 · « **Reply #26 on:** October 23, 2007, 05:10:02 PM »

What do you want your robot to do?

Admin · « **Reply #27 on:** October 24, 2007, 04:45:45 AM »

Look for sample code that uses your servo controller and figure out how it works. Google around for a bit, and check their forum for users who posted code.

(one of my biggest complaints about Pololu is they rarely write sample code for their own products)

Hmmmm what sensors do you plan to use? Have you considered RoboRealm software?

JumpJet · « **Reply #28 on:** October 27, 2007, 09:38:29 AM »

right now I would be happy if I could use the arrow keys to run the motors.
I have installed roborealm but I don't have a webcam.
I need a compiler right?

airman00 · « **Reply #29 on:** October 27, 2007, 05:47:27 PM »

compiler for what?

In what language can you program the serial controller in?
Is it just directly to the serial port?

with my experience with Phidgets , I used Visual Basic. But then again ,that was an HID USB device

Hmmm, on Roborealm there are ways to control the serial port directly. Then you would have to find the proper command on the serial port to control it. Do some tutorials on RoboRealm and if you have any questions post on this forum or on the official RoboRealm Forum.

,Eric

p.s. I would suggest the Logitech Orbit webcam, it can pan and tilt. I bought mine on ebay.

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Author Topic: I want to make a PC-bot (Read 16197 times)