/diy/ - Do It Yourself

[Anonymous No.545458]

Hi /diy/, I want to know where to begin if I want to create mobile machines which would be able to communicate between each other over a distance the size of a football (UK) pitch preferably through wifi.

I guess this would involve robotics. So yeah, where should I start if I want to learn robotics and things of the sort?

>pic unrelated

[Anonymous No.545461]

Cups and string bro, cups and string.

[Anonymous No.545463]

>>545461

Sorry, I should have been more specific. These robots will be no larger than 50 square cm and will need to send data to each other and to a main computer which collects the information and sends them new positional instructions. I am planning to use their own sizes and a set starting point to get them to position themselves relative to each other. This would stop me from needing to create a local positioning system which would be impractical, costly and overly accurate.

[Anonymous No.545469]

Wifi gets complicated when you are dealing with robots, especially if you are using microcontrollers since the only wifi modules that are designed to work with microcontrollers are expensive and you would need to implement your own communication protocol (aka how does the robot receive commands over wifi). If you step it up to an embedded linux computer such as the raspberry pi, or my personal favorite the beagle bone black, then wifi becomes significantly easier (and cheaper since you can use off the shelf usb wifi dongles). Using embedded linux systems gives you more power than you need though since you say there will be a central computer controlling them, and this also makes programming the robots hard since the amount of work it takes in code to say turn on a motor becomes significantly greater when you use an embedded linux computer (there is just more layers standing between you and turning on a motor). So here is what I would suggest doing, get an arduino and learn to use low cost radio modules (the nRF24l01+ is in season). You will probably want to buy arduino clones (program them like arduino, same shape size and specs as arduino but cheaper) for the robots and then have an arduino connected to the computer interfacing to the wireless radio.

This is a lot to try and take on especially if you have no prior robotics/programming experience, if you want there are plenty of irc channels that you should go to and ask for help/guidance. #arduino in chat.freenode.net

[Anonymous No.545477]

>>545469

Thanks. Would you be able to recommend any books so I can teach myself how to actually make robots? I will look at Arduino but I would prefer to learn how the robotics work at a lower level and how I would be able to create them without the help of Arduino. I'll have a better grasp of what's capable with that knowledge.

[Anonymous No.545481]

>>545477
that is kinda hard to do, unless you relish setting up large logic arrays that wouldn't in your wildest dreams fit into a 50cm cube then you are going to need some sort of controller. something that tells the motors to spin and receive these instructions. You have a few options as I mentioned before but you need NEED some form of controller board. Arduino just has the largest community behind it, the most accessories made for it and some of the offerings out there have quite a bit of computational power. As for robots in the sense of the frame, body, and motors I couldn't really help you since anytime I worked on a robot I was part of a team and always handled the electronics.

[Anonymous No.545482]

>>545481

Fair enough I'll look into Arduino then. Are there any books you would recommend that cover the electronics in robot then?

[Anonymous No.545484]

Lego mindstorms. You can connect them to the pc with bluetooth, and there's a variety of libraries out there that allow you to program it in your favorite language.

Thank me later.

[Anonymous No.545485]

>>545484

I plan to turn this into a business or service. I doubt Lego would be a good starting point. I have considered it as it has been suggested before but I figured that, not only would it cost too much, but I wouldn't have as much control of the hardware as I wanted. I need to get a grip of how much each unit will cost me.

[Anonymous No.545487]

>>545482
http://www.makershed.com/Make_an_Arduino_Controlled_Robot_PDF_p/9781449344375-e.htm
http://www.makershed.com/Arduino_Cookbook_2nd_Edition_p/9781449313876-e.htm
http://www.makershed.com/Make_Arduino_Bots_and_Gadgets_p/mmfabg.htm
pretty much everything in this catalog that is relevant to what you are trying to do, make has good content but unfortunately they overcharge so I would suggest finding titles from the store and downloading them from somewhere else. http://www.makershed.com/category_s/271.htm

[Anonymous No.545494]

>>545487

Thanks.

[Anonymous No.545499]

>>545487

What would you say is the smallest possible arduino robot that moves do you think I could build? 10 square cm or smaller?

[Anonymous No.545508]

>>545499
depends, there are other microcontrollers, one I know of and use is called the teensy 3.0 it has a very powerful processor and many input output pins, also it is about 1.4 x .7 inches and completely flat. but when you try to scale it down that small you start to run into the problem of your motors being too big or your battery taking up too much space.

[Anonymous No.545511]

>>545508
oh also it is "arduino compatible" meaning that you can program it using the arduino programming environment, so anything you learn from arduino books can be applied to it. It even has some extra goodies such as multiple spi ports (basically means you can have a lot of sensors, screens or other microcontrollers attached) several uart ports, a built in real time clock and many other goodies.

[Anonymous No.545538]

>>545499
Depends on what you want it to be able to do, if you want it to move on a flat, even surface, two small wheels and a caster are fine. Battery size greatly depends on how long you want to be able to move it per battery charge. I don't know about the wifi/bluetooth things but just microcontoller (the mentioned teensy for example, I recall seeing an Attiny based one somewhere), just the controller+motor+Battery+wheels should be able to fit in a 5x5x5cm cube.

Lookup the competitions with robot mice navigating in a maze, these people know their way around tiny electronics and positioning

[Anonymous No.546005]

I broke my iPhone 4S screen when a bee stung my hand and it shattered. I researched my options and rather than pay some scrub $60 or pay $150 to Apple I decided to buy the tools to fix it myself.

How hard is it to replace the screen, and what are my risks of fucking it up?

[Anonymous No.546010]

>>546005
I have no idea how hard it'll be to replace the screen but be wary that man, taking that screen off without fucking anything else up is hard.

[Anonymous No.546057]

>>546005
Cake walk. There are plenty of instruction videos out there to do this. Just go slow and be careful not to just rip things off. It's all wired up using ribbon cables, and those are very easy to break.

[Anonymous No.546058]

>>546005
..how can a bee stinging your hand shatter your screen..?

[Anonymous No.546064]

>>546058
Big bees.

[Anonymous No.546085]

>Wifi
Nope
Use those $2 2.4Ghz modules. They've got great range at low baud rates and in the open

[Anonymous No.546258]

>>546057
>ribbon cables
Ugh, those things remain the bane of my existence when working on my laptop.