Robot Lawn Mower

Today I am working on installing the software for the RazorIMU, but first I should describe what the heck it is and why it is useful.

The RazorIMU is a 9 degrees of freedom inertial measurement unit. It integrates a accelerometer, gyroscope, and magnetometer (each having their own three axis measurement). The accelerometer measures changes in movement. The gyroscope measures changes in angle. The magnetometer works as a compass.

These three being integrated to provide a simple means for navigation. This coupled with video from a USB camera, and wheel speed from the encoders should give the robot everything it needs to be autonomous.

The RazorIMU look like this:

It is missing a good way to connect it to a computer. To fix this we will add a FTDI so that it can communicate over USB. The FTDI is a simple USB to serial adapter. The adapter needs to be setup to use 3.3V NOT 5V. Now we have a description, purpose, and how to hook it up, we can move on to how to use it.

We will be using the instructions from the Github page: https://github.com/KristofRobot/razor_imu_9dof .

The instructions for any ROS driver is super generic due to how they are a single piece of an undefined machine. Instructions instruct to install the dependencies first and then it moves into crazy land. The instructions tell you to download the code to your catkin work space. The catkin work space is a folder that contains the different stuff you need for your robot. This seems counter-intuitive, but once you read the fun time ROS wiki: http://wiki.ros.org/ , you will understand it a little more. Basically, you make a folder and put a src folder in that folder and add the CMakeLists.txt and package.xml files and throw them in there... you add files and build them. This makes a nice little area for a robot's software to hang out. TLDR: The folder name shouldn't matter as long as it is setup as a catkin work space.

Go to the robot software src folder and download the code from github per the instructions.

The IMU can be programmed using the Arduino IDE. The process isn't super straight forward on the instructions page. You have to be able to differentiate what kind of RazorIMU board you have and then comment out all the other types of Razor types.

Once you get the file uploaded and you go through the rest of the instructions you will be able to do this:

Yay, that person!

02/02/2017