Digitizing the Em2

Some of you may be familiar with the Raspberry Pi minicomputer concept. Some of you might also be familiar with the Arduino digital interface/controller. My colleague Todd ordered a Raspberry Pi and it arrived this last week. I couldn't help but imagining how we could incorporate this tiny little computer into our Em2 hacks.

The Raspberry Pi has a few advantages over the Arduino board that makes the Pi a better base platform for digitizing the Em2.

Linux-based operating system, programming opportunities with Python

HDMI output for display on a large monitor

USB input/output for keyboard, mouse, hard drives, Kinect scanner, etc.

Ethernet (10/100) connectivity

SD card as boot/flash drive (download/mount data and images with regular computer)

General purpose Input/Output pins for connecting other devices

That last item - the I/O pins provide opportunities to connect to digital devices like the LRRD's digital flow controller, or other sensors that could collect data and then combine and sync all the output.

My first priority is to get the Raspberry Pi to talk to the Kinect and automate the 3D scanning process. Ideally, we'd have two Kinects to cover the entire stream table. These would then be linked to an overall timeline of a particular experiment run (with information on discharge, sediment supply, and base level). There is a digital camera in development (5 MP) that could form the basis of photogrammetry measurements. Being automated, one could lock the cameras into position to maintain consistency.

My dream setup includes a Raspberry Pi (or two) controlling:
•Discharge from digital flow controller (or monitoring via simple Ventury tube, pump voltage, etc)
•Kinect/3D data
•Sediment Supply system voltage (either the LEGO version I've got, or something more robust)
•Base Level elevation measurements
•Time lapse photography
•Optical sediment sensor consisting of a UV LED to record the presence of individual fluorescent plastic bits that make up a small fraction of the sediment (as an estimate of bedload transport)
•All synchronized to a single timeline

So, I'll keep on hacking and we'll see where we're at in a month, semester, or year, etc. Who knows - these kinds of things always end up changing as new opportunities arise, plans end up being overly ambitious, technology doesn't cooperate, or whatever. The thing to keep in mind is that (to rephrase John Lennon) "Research is what happens while you are busy making other plans."