Society of Robots - Robot Forum
Electronics => Electronics => Topic started by: Adityav95 on May 04, 2010, 05:30:33 AM
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Hey guys/girls, I'm looking to build a robot and have read the $50 robot tutorial and it will be my first robot build. I'm also going a build a robot with the roboduino or arduino micro-controller.
1. Firstly i learnt that the Arduino Duemilanove (link: http://store.curiousinventor.com/arduino/arduino-duemilanove.html (http://store.curiousinventor.com/arduino/arduino-duemilanove.html)) is based on a ATMega 328 while the roboduino is based on the ATMega 168. Since the roboduino is more expensive than arduino, ($30 vs $35) and has the faster ATMega 328 is it not better to go for the Arduino?? ???
2. Is it easier to use roboduino or arduino?? ??? since I'm a beginner i would like things to be as easy as it can be. ;D
3. this robot I'm building with the arduino/roboduino is planned to be fitted with the paralax ultra sonic range finder as in the $50 robot sonar upgrade tutorial, so which is the better(and more importantly easier ) controller to use with it? ???
4. if i buy the arduino Duemilanove, do i to solder some parts like the roboduino kit or is it preassembled? ???
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Both boards are the same speed. The 328 just has more memory for more complicated programs.
The robodruino has a built in motor controller, so if you were gonna use dc motors, id pick that.
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Roboduino does not have a motor controller, the Romeo Arduino does
The Duemilanove is always preassembled.
The Roboduino would be easier for things that you want to achieve.
You can always replace the mega168 with the 328, the 328 costs like four dollars.
Anyways, for your use, you won't need a 328 anyways since the 168 should have plenty of space.
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Oops. I'm getting old, my memory is getting jumbled.
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thnx, ;D so ur saying the roboduino is better. but i still have an over sized list of questions. :D
this is what i think i need for my build of an object avoiding bot:
1. 2x hitec 425bb servos
2. paralax ping ultrasonic sensor
3. roboduino
4. 7.2v battery pack (hopefully it will be enough)
5. all the other stuff for the chassis and all that.
is this all i need? ??? (i mean do i need a servo to move the sensor around for object avoidance or is it okay if it is just stuck in one place without having to 'look' around ???)
do i require a shield to connect my servos like in the arduino duemilanove (link: http://www.societyofrobots.com/robotforum/index.php?topic=8492.0 (http://www.societyofrobots.com/robotforum/index.php?topic=8492.0)) or is it just plug and play? ???
i found some batteries which are 7.2v 2000mAh for $6-7 but they have bear leads (link:http://www.all-battery.com/72v2000mahnimhrechargeablebatterypackforwalkingrobotsandrcplanes.aspx ) (link2 : http://www.all-battery.com/72vnimh2000mahbatterypackforwalkingrobotandhpimicrors4car.aspx (http://www.all-battery.com/72vnimh2000mahbatterypackforwalkingrobotandhpimicrors4car.aspx)), so what kind of a connector do i use to connect it to roboduino? is this the only battery i will need to power everything (servos, paralax ping ultrasonic sensor, roboduino)? also i would need a charger that will charge the battery very quickly and it should work between 100-240v(very important as in India we only get 220-240v) below $10? can u help me with the connectors and the charger?
also do the servos and the sonar(hs425bb and paralax ping) come with their connecting wires or do i need to buy them separately, and what about the connectors, do i need to find connectors for these too ??? if so can someone pls tell me where to find connectors for these?
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And does the roboduino come with its own usb cable?
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Roboduino comes with it's own USB cable. And it has 3 pin connectors for all Digital and Analog pins, so you don't need a shield. A shield is needed only if you buy the Arduino Duemilanove.
The servos come with cables that plug directly into Roboduino. The Ping sensor needs a Female-Female (3 wire) servo cable, or you make it yourself. Any other sensor you want to plug in, you need to make your own 3 wire cable, with a Female connector that plugs in Roboduino and whatever connector is needed to plug into the sensor. If you buy the Sharp IR Range sensors, also get their cable with the special JST connector. I suggest you get some bare servo cable and lots of 3 pin female connectors and crimp them yourself.
The 7.2V battery is perfect for Roboduino and servos, get the one without the connector, get a switch and a round 2.5mm male power plug to connect it to Roboduino.
(http://www.curiousinventor.com/images/kits/roboduino/roboduino_1_16_layout.jpg)
Good luck!
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@Ro-Bot-X
thnx ;D and by the way wat is the a JST connector? ???
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(http://www.active-robots.com/products/sensors/sparkfun/images/infrared/3pinjump-500.jpg)
The white plug goes into the Sharp IR, and you need to crimp female sockets on the bare wire ends.
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So do i need a servo to move the sonar sensor around or not? ???
and where do i find Female-Female (3 wire) servo cable or if i have to crimp my own cable some bare servo cable and 3 pin female connectors? pls tell me a website that ships locally within the us as even though i'm in india my cousin will be coming soon, so he will be buying it all for me :P .
and what about the 2.5mm male power plug, where do i find that ???
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@Razor Concepts
But i dont thing i'll need those(the Jst connector) as i'll use the paralax ping, which requires Female-Female (3 wire) connectors. :)
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http://store.curiousinventor.com/headers-sockets-connectors.html (http://store.curiousinventor.com/headers-sockets-connectors.html)
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thnx ,is this a male power plug?
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are these the female connectors?:
http://store.curiousinventor.com/headers-sockets-connectors/1-inch-crimp-housing-3-pos.html (http://store.curiousinventor.com/headers-sockets-connectors/1-inch-crimp-housing-3-pos.html)
and the female crimp pins?:
http://store.curiousinventor.com/headers-sockets-connectors/crimp-pins-female.html (http://store.curiousinventor.com/headers-sockets-connectors/crimp-pins-female.html)
and are these the male power plugs i should use:
http://www.servocity.com/html/dc_power_jacks.html (http://www.servocity.com/html/dc_power_jacks.html)
and is it possible to connect the battery to roboduino using a 3-pin female connector or only using a male power plug? ???
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and is it possible to connect the battery to roboduino using a 3-pin female connector or only using a male power plug?
Yes, you can. See the above picture. And the Female crimp pins and housings are exactly what you need.
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If I had to choose, I'd get the Roboduino. Building robots without power bus headers is a real pain. :-X
As a side note, the 168 isn't really supported by WebbotLib anymore (due to memory limitations you won't be able to do much). Webbot had a choice between file size and program quality, and he chose the latter.
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should i mount the sonar(paralax ping) on a servo or is it okay if i just place it in the center of the robot :-\ ???
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If you place it on a servo, you just rotate the servo to find an opening and drive in that direction instead of rotating the robot in place. Less effort for your batteries and the robot looks more "intelligent".
Edit: take a look at this post to see how can you use the Ping sensor on a servo to scan and display the data on a graphic LCD connected to Roboduino:
http://www.societyofrobots.com/robotforum/index.php?topic=7106.msg73126#msg73126 (http://www.societyofrobots.com/robotforum/index.php?topic=7106.msg73126#msg73126)
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@ Ro-Bot-X,
killer robot u've got there! well, for now i'll stick to my design without an LCD but i'll consider using a servo to mount the ping sensor on. Coming to think 'bout it, it does make the robot look more 'intelligent' :)
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will a 7.2v 2000mAh battery pack be enough if i add a hitec hs311 servo to move my ping sensor (considering i'm already using 2xHitec Hs-425bb, roboduino, ping sensor), like will it affect the performance of the robot or something? ???
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Yep, it should be fine.
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thnx
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will a 7.2v 2000mAh battery pack be enough if i add a hitec hs311 servo
Actually, a 7.2V battery will probably fry an HS-311, and if not, significantly reduce its lifespan.
It needs between 4.8 and 6V.
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:o
but doesn't the roboduino regulate the supply of power to the servos? ??? I thought the roboduino restricts the flow to 6v,
well maybe I'm wrong. :(
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but doesn't the roboduino regulate the supply of power to the servos? ??? I thought the roboduino restricts the flow to 6v,
The regulator on the Roboduino can only handle one or two servos before it overheats. Its better to use the unregulated bus.
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Hi,
2 or 3 diodes of an appropriate rating would bring the voltage down into the useable range. Wasteful, but a cheap and quick solution.
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As a side note, the 168 isn't really supported by WebbotLib anymore (due to memory limitations you won't be able to do much). Webbot had a choice between file size and program quality, and he chose the latter.
But yo can replace the 168 with an ATMega328P for a few bucks to double the program memory size
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yeah, i can use diodes but i'll use a 6.0v 2000mAh instead. its a cheaper better alternative. :)
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the 168 isn't really supported by WebbotLib anymore (due to memory limitations you won't be able to do much). Webbot had a choice between file size and program quality, and he chose the latter.
What is the webbotlib anyway and is it a problem if the 168 isn't supported by it? ???
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WebbotLib is a library of source code that makes programming robots *much* easier.
You don't need it, but as Webbot suggested, you can always buy the $3 ATmega328 to upgrade for compatibility.
Note that if you buy an ATmega328, it won't have a bootloader installed unless the seller says it's installed. No bootloader means you need to buy a hardware programmer (from $15 to $36).
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You don't need a hardware programmer. Roboduino can be used as a hardware programmer to program a blank mega328 installed on a breadboard with just a crystal, caps, pull up resistor and ISP connections. You will use the regulated 5V from Roboduino to power the mega328. Take a look here:
http://arduino.cc/en/Tutorial/ArduinoISP (http://arduino.cc/en/Tutorial/ArduinoISP)
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What is the webbotlib anyway and is it a problem if the 168 isn't supported by it? ???
See http://webbot.org.uk (http://webbot.org.uk)
The 168 is supported but you wont fit much onto it - hence ATMega328P gives you at least another 16k for your own program.
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Dude, just get a Roboduino and start working with it! After you fill up the mega168, you will have enough experience to burn a bootloader in a blank 328. Admin was right in the previous post that you will need a hardware programmer if you decide to use Webbotlib, as you need the space the bootloader is using. So just get a board, start using it with Arduino, build a robot, then go for something more complicated.
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yeah, i think i'll just use the stock atmega 168 that comes with roboduino and think about the 328 with webbot compatibility later, i think 16k is more than enough for this build. :)
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hey guys just check this battery out:
http://www.all-battery.com/6v2000mahnimhsidebysiderxreceiverbatterypackswhitecconnector11106.aspx (http://www.all-battery.com/6v2000mahnimhsidebysiderxreceiverbatterypackswhitecconnector11106.aspx)
any idea on a charger that will work with 220-240v(approx) to charge this battery pack??
need to charge this thing to get it working. not willing to spend more than $10
Thnk u