You want your first robot to start learning robotics, but don't know where to start? You don't know if you can build your robot by yourself? Maybe you should go for a kit, but isn't it cheating to buy a kit instead of building it from scratch? And where can I find the money to buy it?
Just like you, I had all these questions before I started in robotics. So I will show all the opportunities you have, and explain the pros and cons of each of them.
There is no single best solution for all. If you know a lot of electronics, or if you want to focus on programming AI, the solution will of course be very different. Plus, you have to take into account your budget.
What do I mean by builders first? I mean people who don't want to buy a standard platform that is ready to be programmed. If you want to be able to add sensors as you go, or change the whole shape of the robot, you have to build it yourself. People who want to focus on programming may be more interested in standard platforms in the next part below.
Actually, kits are a great way to start, because they made all the design for you. If you buy a robot arm kit, they made sure the structure is strong enough, the motors powerful enough, etc... If you buy a Lego Mindstorms NXT robot kit, you are sure you can use all the sensors as easily as plug and play.
Also, with some kits like Lego and Bioloid, you have an easy programming interface, and both can change shape and purpose very quickly if you want to try something new.
Kits are a great to learn design and programming. But don't forget that if you want to design a real robot, or program like a pro, you'll have to get out of their framework. You'll have to learn to add your own code in C/C++ or other programming language. Plus you won't learn much about basic electronics.
My first Arduino Robot: It can move and avoir walls (really, it can!)
To learn electronics, you will have to build your own robot from scratch. For that, you will need a microcontroller like Arduino, which is simple to use and has a lot of documentation. Your microcontroller is like the brain of your robot, and will command the motors, receive data from sensors and all.
My first robot was a robot arm kit, and I got it for a project at my College. It was very fun to build the kit, and easy to use so that I could have a demo running quite easily. Also, it was free, since my college paid for it. The drawback is that I didn't get to keep it later.
My very first robot
A drawback for all these kits and DIY robots is that they mostly lack of computing power. The robot will be good depending on its design and focus on realizing a task. But it will never be a robot that can do anything and everything, and have advanced AI.
If you want to focus on advanced Artificial Intelligence and robots, you may want to buy one of those standard platforms that have a better CPU, integrated sensors, and sometimes development tools.
The main platforms for that are Aibo and Nao. There is also the Darwin-Op that was created recently. These are all so advanced that they are commonly used in reseach laboratories.
Aibo can only be found second hand. I have a Nao myself, and you can get it through the Nao Developer Program.
They are also a lot more expensive, since they are like a mini-computer on legs. If you want to go a little lower in prices, you can make a PC bot: you need a sturdy mobile platform on which you put your PC.
The iCreate or a Roomba are the perfect fit for a PC bot. You may also need to run the ROS (Robotic Operating System) or the like to create the architecture of your robot. You can buy the whole thing ready to use under the name of TurtleBot, or BiliBot, both adding a Kinect on top for more possibilities.
Talking about Roomba leads me naturally to the last category of robots: the useful ones.
If you buy a Roomba, you buy a vacuum robot. You can hack as much as you like during the week-ends, it will always be useful during the week to vacuum. In a way, you can't lose when you buy one, even if you finally never use it to program and create your own robot.
There are also many toys that can be hacked with official approval. The dinosaur robot Pleo is a cool robot toy, and has an official SDK (programming tools) to create your own behaviors using its many sensors and decent CPU.
still, but much more limited is the MyKeepon. It's really a cool toy,
and you can program it too. But it can't do much around.
You may also be interested in these pages:
The Nao Developer Program. How can you get a Nao to make awesome robotic applications?
Why not choosing a robot arm kit? A robot arm kit can be a great choice for a first robot, and if you want to learn more about industrial robotics or humanoids. And they're cheap.