Human body motion tracking with FreeIMU

John Patillo, one of the very first guys in starting a "child" project based upon my FreeIMU hardware and library, just posted a comment sharing his last progresses in his own Smart Skeleton project.

John, who's a Biology and Human Anatomy & Physiology College teacher by day and an Arduino/electronics hacker by night, is working on using inertial sensors in FreeIMU to track human body motion.

Hi Fabio, I hope all is going well with your studies. I just wanted to give you an update on what I've been doing with my modification of your FreeIMU circuit. After I lot of work with a logic analyzer, I finally got multiple IMU's talking to one arduino without tripping over each other. Now I'm working on the software. The video shows three IMU's (in white plastic boxes) attached to a skeleton arm. These are communicating with an arduino using i2c over flat cat5 cables. The arduino is hidden behind the laptop. The sketch I'm running here is a modification of your FreeIMU cube sketch. There are a few calibration issues to work out, but I gotten over all the major technical hurdles. I couldn't have done any of this without your hard work on the FreeIMU libraries. Thank you very much!

Following a picture of the "Skeleton IMU" John designed basing upon FreeIMU, designed especially for daisy-chaining using the PCA9509 I2C repeater to allow long wires on the SDA and SCL I2C bus lines. Using the PCA9509 also allows to have an enable pin which allows to communicate singularly with each IMU (Similarly to what happens with the CS channel in the SPI bus). For connecting the various IMUs, John is using flat cat5 Ethernet cables and connectors which delivers the signals just fine. Very smart.

Even if commercial and research projects focused on human motion tracking using inertial sensors have been around for quite some time, I'm sure that an open hardware/libre software based project would be really great to have as I'm sure it could be a very good starting point for many medical, virtual reality, sport, etc. projects.

I'm really looking forward having access to more details on this project. John, where are you putting out some sources/design??? ;-)