I am an architecture student at the University of Edinburgh working on a remediation project for a beach contaminated by radioactive waste. I have a large set of data including latitude and longitude coordinates and the radioactive strength for radioactive particles that have been found (and since removed) from the beach. I would like to create a device using a nexus 4 phone and arduino to send a warning to the user - pulsing LED lights - that they are standing in close proximity to these locations. The LEDs could flash in different colours according to the strength of radioactivity, which of course is already known. You could think of it almost as a reverse geiger counter.
I am an architecture student and have no knowledge of arduino or programming. I was wondering if anybody could give advice as to how to make this device, which should accurately track GPS location and when these match or are close to those of a known radioactive sample on the beach, be able to refer to the known database for radioactive particles on the beach and indiciate the strength of radioactivity. The principle is similar to geofencing although it needs to use GPS coordinates rather than ping wifi signals so that is can be more accurate. Here is a map I have made of the data Dalgety Bay - Google My Maps
You could build such a thing as a standalone app on the phone if you're prepared to give up the physical LEDs for something you see on the phone's screen - what's the driver for adding LEDs and an arduino?
We intend to design a wrist device with a simple radioactive symbol that illuminates as you approach the GPS coordinates of known radioactive samples. Is there any way of using the nexus 4 as a gps? I am now looking into adding a gps shield that will compare the live coordinates to a library of the radioactive sample locations...
A Geiger counter will almost instantly tell you if you are near a radioactive sample. I've seen wristwatch sized Geiger counters, but I doubt they are very sensitive.
EsalaDE:
Yes, in fact I just found this app for android..
I must say I don't understand the need for any device apart from the phone - I presume the people with this kit will be aware of what is going on and won't ignore the phone in the way that Joe Public might.
It should be easy enough to write an Android program to do what you want.
If you really do need the wrist mounted device then the Android App that you linked to and a small Arduino with a Bluetooth module should be simple to implement.
You will need some sort of reassurance protocol to make sure the wrist device is actually paired with the phone belonging to the owner of the wrist and not to the phone in his/her colleague's pocket.
I'm guessing that the purpose of the exercise is to be able to return to the original locations to check for any residual radioactivity and, since you hope there will be none, a geiger counter cannot be used as a locator.
And now, let's pull back the curtain and have a look at the elephant ... where did the radioactivity come from?
One of the most interesting features of a beach is that the contents can move rather dramatically from year to year. Not far from my home, I've seen the sand disappear almost completely from one beach, in just one year's time, due to a change in the coastal currents.
In such a case, a Geiger counter would be much more reliable than a map someone prepared a while ago.
The radioactivity is from incinerated radium dials of wwII airplanes which were disposed of in a landfill near the beach site.
The point of the exercise is to visualise the data on the actual site so that the data becomes perceptible. Essentially the aim is to make the invisible, visible through the device. Going to the beach at night with a camera mounted on a tripod, we hope to record somebody walking the beach, wearing the device and we will be able to record through video or long exposure shots the areas where the wrist will illuminate. We are using old data points because we are not intending to build a geiger counter.