robo-computer

[John Gutmann]

i was look at things on the internet of how some people have built there own robot out of an old computer, and i was just wondering how to do this, like how would you program it and everything, it would be awesome to beable to do but i just dont see how they would program it and everything because of the overall complexity of the system and sub system

[mechanicalbrain]

you think that was impressive look up white box robotics. their entire robot is literally a PC VERY well done. looks kind of like R2D2..... anyhew that is also one of the most impressive robots Ive ever seen (because of the price). sorry not exactly what you asked. you need to integrate a PC with some type of motor control board. you could do it with the FIRST board. the programming is no different.

[[527]phil]

We'll from what I've learned you have to use PC cards and certain ports. Check out http://www.xrobots.co.uk/modules/news/ . this guys build android style robots a few that use PC's. Also you might need to get/make a special chip that plugs into the serial port on the computer board. you also need special programs to connect to the external chips.

[mechanicalbrain]

^ not necisarily you could even use a basic STAMP board and plug into a serial port.

[scitobor 617]

Actually its not hard at all. This summer I've been retro fitting a small gas powered vehical to be controlled by an x86 PC. The PC is controlled by another PC over a wifi card. The networking stuff is kinda complex, however the parallel port is great for controlling realys and reading data from sensors like limit switches. The code for that is very simple and not hard to learn. If you are adventurous then there are pretty cool microcontrollers that can be connected to usb. Also, there are many serial options like the basic stamps. For my robot I have designed my own realys because I did'nt have the cash for Spikes. Also I am using a microcontroller that connects to the usb port that way I can connect many microcontrollers and therefore have countless sensors and motors. If you want to see code I would suggest reading the following, all of my code is in C and C++, also I am using Linux but Window$ could probably allow you to do much of the same things. All bets are off when it comes to Macs, not really but options become limited by the ports on them.

http://www.phrack.org/phrack/50/P50-11
http://www.epanorama.net/circuits/parallel_output.html
My parallel port test program(Very messy)

[John Gutmann]

no i mean like how do they get them to run, so that you just can control it from sumthing, if you have to intergate th r/c with it or a basic stamp the only thing ur doing is making the basic stamp complex wit the comp, like do the comps has an os on them? and the programing that they have do they have to do sumthing special so when it starts(if it does have an os) to run the program, i know how to do wireless and how to interface wit stuff i mena like how do they do it programming wise?

[mechanicalbrain]

i cant say that i know exactly how to do it but i recomend insulating the motors from the PC if you run them on the same electrical system.

[team222badbrad]

Originally Posted by scitobor 617

Actually its not hard at all. This summer I've been retro fitting a small gas powered vehical to be controlled by an x86 PC. The PC is controlled by another PC over a wifi card.

That is cool. What kind of gas powered vehicle?

Check this out!

Its not gas powered, but it is basically a stripped down E-maxx.

http://66.221.222.55/proddetail.asp?prod=Robot3&cat=17 (robot)


www.traxxas.com (E-maxx)

[half geek]

http://gumstix.com

Very nifty little ARM-based, low power, and high capability things. They run linux 2.6.1, can have integrated bluetooth, comes with SSH server installed, has the capability of being a web server, and on and on.

I have never tried them, but I hear very good things.
My birthday is in November....

[mechanicalbrain]

yeah their very nice and networkable!

[scitobor 617]

Originally Posted by team222badbrad

That is cool. What kind of gas powered vehicle?

Its a riding lawn mower which hopefully I can make fully autonomous by next summer.... I really hate to cut the grass on hot Virgina summer days.

[Jizvonius]

What would you be attempting to do with this robot?

If you use a computer (laptop or desktop) for the processing and control, I would hope that it would be relatively calculation/memory intensive. (ie. autonomous nav using image processing) Otherwise the system will be very overpowered in the processing/memory department.

The only low level programming that would really have to be done is to output the control signal's for your actuators. This would reqired motor drivers which can use anything from a pwm signal to a binary number to pass values to control your actuators. As far as I know, computers do not put out pwm signals by themselves so if you were to go that route, external circuitry would be required in addition to the motor drivers. If your motor drivers were to use a pin based x-bit (x is variable) signal, they would be able to take sets of pin values from your serial port to control the motors. Either option is viable and actually just changes the clocks for your motor controllers to either a central one or separate ones.

All more complex calculations could actually use a higher level software package such as MATLab, which if I remember correctly has a serial output function of its own.

(and yes motor power supplies etc. need to be isolated from the comp which is generaly the case with good, high current motor drivers anyway)

Disclaimer: any errors in this post may be attributed to me being an ME major and not fully understanding the intricacies of magic smoke.

[[527]phil]

I suggest getting the book "robot builders bonanza" it gives detailed instructions on how to use a computer as a robot brain. Your best bet is to make a 2 motor robot and control it using the printer port.

[mechanicalbrain]

i agree with ^. i have personally read this and its good for that however i found it really better at building from scratch and i do not do that so i only read it at the book store and never went into depth. however its still a good book. i also recommend using the joy stick port for your sensors. (however this kind of limits you )

[John Gutmann]

Originally Posted by mechanicalbrain

i agree with ^. i have personally read this and its good for that however i found it really better at building from scratch and i do not do that so i only read it at the book store and never went into depth. however its still a good book. i also recommend using the joy stick port for your sensors. (however this kind of limits you )

how does the joystick port limit you, doesnt it have analog and digital inputs