Society of Robots - Robot Forum

Electronics => Electronics => Topic started by: robonoob on December 05, 2007, 08:33:19 AM

Title: Hi Im new and i wanna know some things... :) plz help me with that
Post by: robonoob on December 05, 2007, 08:33:19 AM
Hi as i said in topic im new... and i mean it. im new to the whole electronics thing :D i've beel looking around the whole forum for now and i have some questions...first i wanna know about scavenging stuff...well i have an old computer,  about 5 mice several monitors 2 of theese things that poewr the whole computer...(I dont remember its name :D) and i eaven have 1 old touchsensitive mobilephone...mby theres something more but i cant remember atm... anyway. what i want to know what can i scavange out of them... can i take something from a computers motherboard? wrom where could i get a microcontroller for my first robot i wanna start making soon :D and what things have any good electronics in them? as i said i am quite new to the whole electronics, so could you please explain what do the things look like in theese old computers and what ever...
OK what else do i wanna know... oh yea...what is "IR sensor" i've read that they are in mouses mostly...but what do they do or what can i do with them? can i use them on my robots?
and lastly everybody is talking about some code :D what is the"code"?? :D i've seen many pages that allow u to download the robots code... but it doesnt tell me anything :D so i'd be very grateful if you'd answer my questions :D:D

PS: i know there is a lot of text i just wrote :D but yea... plz read it and answer me :D
PSS: just one more question:D ... i have looked for answers for this  from this forum but im still confused...what is the h bridge used for and what is it anyway :D?
Title: Re: Hi Im new and i wanna know some things... :) plz help me with that
Post by: cooldog on December 05, 2007, 11:15:41 AM
mother boards have tons of capacitors, LEDs and wires
Title: Re: Hi Im new and i wanna know some things... :) plz help me with that
Post by: Admin on December 05, 2007, 01:50:34 PM
scrapping computers? its been asked a million times already:
http://www.societyofrobots.com/robotforum/index.php?topic=990.0

 ;D

Quote
what is the h bridge used for and what is it anyway?
http://www.societyofrobots.com/schematics_h-bridgedes.shtml

That tutorial is kinda out of date, as I no longer recommend making one. Instead, just buy a motor driver, motor controller, or ESC (whatever you want to call it). They can be fairly cheap ($10-$120), depending on your specs.
Title: Re: Hi Im new and i wanna know some things... :) plz help me with that
Post by: robonoob on December 05, 2007, 02:29:35 PM
well... i looked that motherboard but it doesn't have any LEDs on it but yeah it sure does have a lot of capacitors :D
i have allready  read this computer scraping(or whatever :D) i didn't hind anything interesting there unfortunately... expert that comps power supply thing... pench-top power supply? what is that? :D:D
and about that h-bridge... I've read this tut too :D but yeah..its too complicated for me :( and these motorcontrollers can anybody tell me when could i scavenge these out or something cuz i live in a little country and i cant buy these things from shop :D and no page ships anything here too :( so yeah... thats because I'm mostly a scavenger :D
thanks anyway :)
Title: Re: Hi Im new and i wanna know some things... :) plz help me with that
Post by: Admin on December 05, 2007, 02:38:04 PM
estonia isnt that little :P

nope, its nearly impossible to scrap a microcontroller - much easier to just buy one

you should try out my $50 robot tutorial, and make the robot chassis out of the computer casing :P
Title: Re: Hi Im new and i wanna know some things... :) plz help me with that
Post by: airman00 on December 05, 2007, 06:04:02 PM
ummm robonoob , whats with all the smilies  :D

It kinda got me distracted from what you wrote    :P
Title: Re: Hi Im new and i wanna know some things... :) plz help me with that
Post by: robonoob on December 06, 2007, 07:42:23 AM
ummm robonoob , whats with all the smilies  :D

It kinda got me distracted from what you wrote    :P
yea I'm sorry, just a bad habit..
but to admin...yes Estonia is too little and i cant order a thing here from like UK or USA :(
but i still want to know what is The "code" that everybody is talking about and what can i do with IR sensors?
Title: Re: Hi Im new and i wanna know some things... :) plz help me with that
Post by: Admin on December 06, 2007, 08:00:09 AM
this company will ship what you need to Estonia:
http://www.rs-components.com/full.html

(and many other 'small' countries)
Title: Re: Hi Im new and i wanna know some things... :) plz help me with that
Post by: Trumpkin on December 06, 2007, 11:07:58 AM
Code tells the robot what to do read the $50 robot tutorial. The IR sensor can be used for a lot of things, in the $50 robot it's used to follow objects.
Title: Re: Hi Im new and i wanna know some things... :) plz help me with that
Post by: dunk on December 06, 2007, 11:08:43 AM
Quote
but i still want to know what is The "code" that everybody is talking about
i think you mean the program which runs on a microcontroller.
http://www.societyofrobots.com/microcontroller_tutorial.shtml (http://www.societyofrobots.com/microcontroller_tutorial.shtml)

dunk.
Title: Re: Hi Im new and i wanna know some things... :) plz help me with that
Post by: robonoob on December 06, 2007, 11:08:56 AM
this company will ship what you need to Estonia:
http://www.rs-components.com/full.html

(and many other 'small' countries)
OMG thanks :D i appreciate that :)
Title: Re: Hi Im new and i wanna know some things... :) plz help me with that
Post by: robonoob on December 08, 2007, 03:13:26 AM
i still want to know about thees IR sensors... the $50 robot uses normalphotoresistors but not IR sensors... and i was wondering how do the IR sensors look like anyways? :D
Title: Re: Hi Im new and i wanna know some things... :) plz help me with that
Post by: HDL_CinC_Dragon on December 08, 2007, 10:17:00 AM
(http://www.junun.org/MarkIII/bigimages/item73.jpg)
Standard Sharp IR range finder (IR sensor)

Basically it shoots out a beam of infrared light from its IR transmitter and calculates how much time it took that IR to bounce back to the IR receiver and uses that to determine the distance of the object in front of it.



Also, the standard $50 robot tutorial uses photoresistors as eyes but there is a link at the end of the project to upgrade both the micro controller and also the eyes into IR sensors.
Title: Re: Hi Im new and i wanna know some things... :) plz help me with that
Post by: robonoob on December 08, 2007, 11:12:36 AM
OK i get it... but i read somewhere that there are IR sensors in computer mice too... so looked up a picture http://en.wikipedia.org/wiki/Image:Mouse-mechanism-cutaway.png it says infrared LED.
is that the IR sensor? :D and if it isn't then how can i use these infrared LED's on my robots? just like a normal photoresistor? or do i have to use the other sensor too thats on the mice?
Title: Re: Hi Im new and i wanna know some things... :) plz help me with that
Post by: HDL_CinC_Dragon on December 08, 2007, 11:27:26 AM
Well those work like this: There 2 bars perpendicular to each other that are turned by the ball as the ball moves. Each bar represents one Y axis and one X axis. These bars are connected to one disc each. This disc has either small holes around its outside edged or teeth around its outside edge. The IR is constantly emitting from an IR LED transmitter and picked up by the IR receiver. The teeth or holes intermittently block and allow the IR to reach the IR receiver. Using the frequency in which the IR beam can be seen and hidden from the receiver determines how fast the user moved the mouse and how far.
Title: Re: Hi Im new and i wanna know some things... :) plz help me with that
Post by: robonoob on December 08, 2007, 03:19:59 PM
Well those work like this: There 2 bars perpendicular to each other that are turned by the ball as the ball moves. Each bar represents one Y axis and one X axis. These bars are connected to one disc each. This disc has either small holes around its outside edged or teeth around its outside edge. The IR is constantly emitting from an IR LED transmitter and picked up by the IR receiver. The teeth or holes intermittently block and allow the IR to reach the IR receiver. Using the frequency in which the IR beam can be seen and hidden from the receiver determines how fast the user moved the mouse and how far.
OK this is the part i understand but still: can i use these IR sensors and receivers in my robots?
Title: Re: Hi Im new and i wanna know some things... :) plz help me with that
Post by: Ro-Bot-X on December 08, 2007, 03:34:53 PM
can i use these IR sensors and receivers in my robots?
Yes. You can use them for wheel encoders or for line following.
Title: Re: Hi Im new and i wanna know some things... :) plz help me with that
Post by: Admin on December 08, 2007, 06:47:40 PM
Quote
Basically it shoots out a beam of infrared light from its IR transmitter and calculates how much time it took that IR to bounce back to the IR receiver and uses that to determine the distance of the object in front of it.
Actually, they don't measure time, they measure angle of the reflected light. The beam is at a slight angle, so the further away the target is, the slightly more shifted the reflected light is when it comes back. There is an array of highly precise sensors that measure this distance. The sensor is also modulated, meaning it is highly resistant to environmental noise. This makes the range go for several feet/meters.
http://www.societyofrobots.com/sensors_sharpirrange.shtml

A normal infrared sensor (http://www.societyofrobots.com/schematics_infraredemitdet.shtml) does not have this array, or the modulation, so its not as good for range finding.
Title: Re: Hi Im new and i wanna know some things... :) plz help me with that
Post by: HDL_CinC_Dragon on December 09, 2007, 12:03:39 AM
eh time, angle, same difference :P


Sorry, got Sonar and IR mixed up there :-\
Title: Re: Hi Im new and i wanna know some things... :) plz help me with that
Post by: robonoob on December 09, 2007, 04:04:38 AM
hey...this may be a reeaaalyy stupid question, but is the IR sensor the same that infrared?  ;D
Title: Re: Hi Im new and i wanna know some things... :) plz help me with that
Post by: Ro-Bot-X on December 09, 2007, 05:25:36 AM
hey...this may be a reeaaalyy stupid question, but is the IR sensor the same that infrared?  ;D
I guess you are puzzled with all this abbreviation stuff. IR means Infra-Red, US means Ultra-Sonic, LED means Light Emmiting Diode and so on.
Usually something that emits light is not a sensor. A sensor is something that receives or monitors a signal or an environment change. An IR LED is an infrared light emmiter, an IR fotodiode or fototranzistor is a receiver, so this is a sensor. There are active sensors, that emit a certain modulated wave (light or sound) and measure the angle or the time it takes for this wave to get back at the receiver of the sensor. Such sensor is the Sharp IR Distance sensor or the Devantech Ultrasonic Range sensor.

But if you take some time to read all the tutorials on this site, you will understand all this by yourself. Then, if you still don't get part of it, you can ask us. Start with the simple things first. If you start with the wavefront algoritm and you don't know what IR is, you won't understand much.
Good luck!