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View Full Version : advice needed before I buy my first robot kit



giddy
07-13-2009, 08:05 PM
hi,

So I'm an advanced programmer (MCTS) but thoroughly into application development.

After doing some research I'm planning to buy a simple robot kit. I dont know too much about electronics but i'm hoping i can program it alright.

What I need is a robot I can control via RF or IR from my PC.... in other words... I need to be able to send instructions like forward/stop/reverse from my pc to the robot wirelessly.

I'm hoping this is not too much of a hassle?? If it is, you could tell me and id go for something simple.

I've got two things to far:
Cheap Trackbot@ robokits (http://robokits.co.in/shop/index.php?main_page=product_info&cPath=10&products_id=213)
Costly robot @ robokits (http://robokits.co.in/shop/index.php?main_page=product_info&cPath=10&products_id=214)

Ibot @ thinklabs (http://thinklabs.in/shop/product_info.php?cPath=53&products_id=182&osCsid=8b20165892f3bc381a96ec60ad25cbc1)
RF remote control @ thinklabs (http://thinklabs.in/shop/product_info.php?cPath=54&products_id=91&osCsid=8b20165892f3bc381a96ec60ad25cbc1)

I'm not sure about the robots at robokits, the costlier one says it has a pc communication link but i dont know if its wireless? The cheaper one has a remote control but i dont know whether I could use it with the pc.

The thinklabs products are separate and I'm assuming could be combined but im not sure it thats possible and how difficult it could be.

So I would like to know which is the simple more suitable robot to buy for a beginner but pretty advanced app developer. are the assembly instructions going to be too difficult and would i need to buy separate products to connect them to a pc and program them? I'm assuming there would be a manual for that?

thanks so much

Gideon

vikas
07-14-2009, 02:30 PM
Track Bot - Remote Controlled is not recommended for you its too simple and works on RC5 remote IR signals .

You have a choice b/w -

TrackBot Micro or Avr ibot , B/w the two Track bot is cheaper and offers more bang for the buck.

Though both are over priced , Trackbot is the one ill recommend.

Also for RF use the RF modeuls from this page
http://robokits.co.in/shop/index.php?main_page=index&cPath=7&zenid=4qu6lro4lsihb2vllv99o248c0

Buy both frequencies to build a transceiver.

giddy
07-15-2009, 11:50 AM
hi,

thanks so much for your reply.

what you mean to say is buy both modules one @433 and other at 315Mhz...it also seems I have to buy a suitable encoder and decoder and there are two avaliable?

Unfortunately I have no idea how I'm going to hook them up?? From the data sheets I can see there are pins for antenna, Vcc, Grnd and data. Two Problems though, it says both the receiver and transmitter connect via the data pin into a MCU... so do I have to get another single MCU with a programmer to connect it to the PC..remember I need to send commands from a pc to the robot?

Secondly, exactly how do i play with the data? What kinda data is it(i'm sorry if i sound stupid) I've never done any AVR C so I'm assuming I can send bits from one MCU though the transmitter and then receive those bits in the other MCU which is in the robot??

If i do have to get another MCU (say ATMega32) where would the data,Vcc go??

Lastly, the MCU based trackbot has AVR programmer as an optional component, I'm assuming I have to buy that to program the robot?

giddy
07-15-2009, 12:15 PM
hi,

So it seems i need a level controller for one of the ends of the RF mod.

I found this article:http://www.uchobby.com/index.php/2007/05/01/simple-rf-wireless-link/

But I dont know what USART, would it work ok without the USART module?

Thanks

Gideon

debu
07-15-2009, 01:36 PM
@giddy: I'm afraid, you will need a USART to use either of these modules. If your microcontroller does not have a hardware USART, you could implement one in software. Software USARTs can run quite comfortably at 2400 baud and 4800 baud, so it should not be a problem.

Regards,

Debu :)

giddy
07-15-2009, 01:49 PM
hi,

Thanks so much.

ok, but i just read its implemented in most MCU, would it be present in an ATMega32..

also, what about an encoder/decoder pair... not sure what it would do but would it make things easier?
http://robokits.co.in/shop/index.php?main_page=product_info&cPath=7&products_id=76

Thanks
Gideon

giddy
07-15-2009, 01:54 PM
Also, I found another DevBoard.. http://xboard.extremeelectronics.co.in/
It seems really nice in terms of documentation and programming, the guy has an abstraction of his own making coding much easier...however problem is i 'll have to buy motors, wheels and a chassis myself..

The robotkits products dont seem to be documented well, I'm not sure of their API and samples. I'm just assuming it would cover basic operations....

vikas
07-15-2009, 04:39 PM
xboard looks nice too. But i would recommend get the whole thing including the robot platform.

It very to easy build a board urself too , but having a proper robot base is a big headache.

From whatever ive seen from Robokits stuff , they provide pretty well supported packages. I have a few boards from them and they are supported with lots of programs.Though these guys are expensive they provide decent stuff.

And the serial port is on the board , All AtMegas have it. The 433 and 315 Mhz IC's need to be used both at a same time , a 4800 bps connection can be established b/w them easily making them the cheapest transceiver around. No external circuitry is required as such. Communicate on the Serial port at 4800 bps :) .

giddy
07-15-2009, 05:35 PM
ok, so I did even more research and if I buy the xboard and the motors, wheels etc from around here, total cost is around 2400, so trackbot is a little cheaper, but robot platform do you mean the chassis, wheels etc or a code layer or something.

Only problem I'm having now trusting them, since it'll be shipped from another state, and of course whether I'll be able to program it ok, since it has a load of parts like the LCD and IR transreceiver. The xboard code looks really nice, functions like WriteToLCD().... completely understandable, robokits doesn't have any sample code so I dont know what to expect.

Thanks so much

Gideon

vikas
07-16-2009, 12:40 PM
XBoard is a neat buy , if you have sources the get the chassis of the robot.By chassis i mean the hardware like the body , wheels etc . Getting a decent robot body is not as easy as it sounds.

Xboard the RX TX transceiver can be soldered right in making it even better. If you are worried go ahead with Xboard nothing to regret there. Get rest of the hardware from somewhere else. If XBoard guy supplied the complimentary chassis and batteries i would have recommended it.

The robokits kit includes mostly everything required,this was the only reason for me recommending it ... itll all fit together out of the pack.

avinash_g
07-18-2009, 01:27 PM
Avoid a common pitfall while using RF modules with USART.

The details are discussed here. Many people asked me same thing so I planned to write an article on it.

http://extremeelectronics.co.in/rf/rf-communication-between-microcontrollers-part-i/

giddy
07-18-2009, 11:18 PM
hi,

Thanks a Lot for your help vikas. Yes I would have liked the XBoard but since I'm a first timer I think I'm going to buy the trackbot. I wont buy until the end of the month though... I will post about how it goes.

Thanks avinash, I did come across your article earlier, am waiting for part 2 though.

I also found this:
http://www.uchobby.com/index.php/2007/05/01/simple-rf-wireless-link/

Thanks so much
Gideon

avinash_g
02-09-2010, 07:35 PM
See xBoard v2.0
http://shop.extremeelectronics.co.in/product_info.php?cPath=23&products_id=111

It is compact, has high power motor driver, easy to use and fits perfectly in Chassis like this
http://robokits.co.in/shop/index.php?main_page=product_info&cPath=60&products_id=273