Hello all,

Thank to the easiness of the mbed platform and great help of the community, I am looking forward to the next steps of my microcontroller education. I would like to go mobile and I am looking for a solution to drive the mbed in the house. As I do not have much time to go from scratch to build a moving platform, I am considering buying a Create from iRobot (cannot find a Roomba to hack on ebay, there are more expensive than a create solution...).

Have anyone used this product? Do you have knowledge of other alternatives?

Thanks

Stephane

When creating my robot, i visited the local discount store called Value Villag)e and found a irobot, without the battery but with all motors and gears working perfect all for $2.99. I have never seen the Create from iRobot but it looks very nice (minus the price tag). If you are just looking for a quick project, you should look for a shop with old stuff and see if you can find something there.

There are also many 4 wheel drive kits that you can buy that come with just the wheels, motor and body. This one from robotshop.ca is only 44$ and its made out of metal so it can take some force. This also gives you many options if you want to add an IR sensor or any other expansion. The Create is pretty much one piece that would be very hard to upgrade or customize.

http://www.robotshop.ca/dfrobot-4wd-arduino-mobile-platform-3.html

There are also different kits that are cheaper and more expensive but in the end its about what you want to accomplish. If its just about learning, the Create from iRobot has everything built and ready to go out of the box. An old iRobot is very cheap but done not give you anything more then two motors and two wheels. The kit lets you build and customize your robot and add anything in the future. Thats just my two cents.

We have used the Create from iRobot for around 20 or so student projects the last couple of years but not with mbed yet. You can control the motors with high level commands over the serial port, read back sensor packets (IR cliff, wheel drop, bumper switch), play tones, control multicolor LED. It comes with the serial cable. It also has a DB25 pin connector to tie into the 18V battery power and some other features of the internal microcontroller. The rechargeable battery and charger is extra so read carefully when you order. Can also do much the same with an old Roomba. There is a hack roomba book and the manuals at iCreate explain the serial commands. You can add quite a bit to it. Here are a couple of the old student projects. You can mount quite a bit of hardware in the back cargo bin. It has been a bit more durable than I expected. At one time, schools could get a discount on a lab pack of ten.

Create  & eBox 3310 with WiFi and WebCam. A plastic sheet was used for the computer mount. It has screw holes in the back cargo area. You can see the built in serial cable on the left.

Printbot

Firefighting Robot with a car windshield washer pump

I have an Mbed on my iCreate robot.  It's a pretty easy interface, you only need 2 wires for a UART, 5v and ground.  All the iCreate commands operate over the serial link.  I haven't gotten much further than simple commands, but when I get the time, I will see what else I can do.

As a robot, I find the iCreate a reasonable deal given it's capability.  You could try the BOEbot from Parallax.  I believe that you can buy it without the Basic Stamp board.  Junun.org has a very capable sumo type robot for $95 (or so).  It would not be difficult to add an mbed to that (I did).

Robotics connection has two robot base kits about the size of the Create. They cost a bit more, but they are all metal assembled parts and not plastic. You can also buy an internal microcontroller board for them with an array of sensors as seen in the final image. You can talk to it over a serial port just like the Create. The one with tank treads is interesting. I don't quite know exactly why, but everyone is fascinated by treads on a robot. Several students here have used them in projects with other processor boards (not mbed yet)

Another low-cost robot base option to think about is to hack a nice RC toy car or truck to build your robot. One year right after Xmas they had the typical 75% off sales. We hit every Radio Shack in town and got twenty big RC 4WD SUV kits for $25 each and used them for a class here. You can add a processor board, sensors, hack into the motor control circuit (find the motor leads and trace back), and use PWM to add motor speed control. You will need to slow it down so that it does not get away from you during development. See the video here on that point. Steering is going to be a bit more difficult that the typical robot kit. They will not just rotate in place unless you use a toy tank. They are fast and durable enough to run outside, unlike almost all of the other low-cost robot kits. This may actually be the lowest cost option, but it takes a bit of work to figure it out and the RC toys are totally different every year so replacement parts might not be available. Hobbyist grade RC models are also an option, but they cost quite a bit more than RC toys. Here are some student projects based on RC toys: