Biometric and position tracking device

Projects General Guidance
1

Dear all,
I'm pretty new to Arduino, I did a few experiments in the past but never a big project involving more than leds and buttons :slight_smile:
I'm planning the development of device that will be used for an art project.
Basically we need to track some vital data while a person walks in a natural trial, together with their location along the trial, and send it real time to a ground station that will visualize them via processing.
I'd like some guidance about that project, basically verifying if the design I came up with and components I've chosen are suitable for the job.

My idea was to stack them all up together (will be 3 shields plus some other devices), collect data and send them to the base station via the XBee.

I have a few questions still:

  • I was wondering whether maybe Arduino FIO would be a better candidate for the project, instead of the UNO, since it looks like it has all the same input and outputs of the UNO, but has the Xbee socket on board, so will save me some money (I need to build quite a few of them) and also some space. It also is powered by a LiPo battery, which is lighter and more eco-friendly that the standard 9V battery of the UNO. Or are there any problems with the FIO that will make it less appealing?
  • Then, I need to talk over the air at distances that might be 1mile or even more. I read that Xbee Pro should reach the mile range. Or is there a way to increase the range? maybe by adding better antennas? or by putting a kind of repeater in between? And consider I'm in Europe, so 900Mhz is not an option
  • Apart from these questions, do you see any obvious faults in my design? Or anything I might have to change?

Thank you

Simone

2

the standard 9V battery of the UNO

That's fightin' talk around these parts, stranger.

3

I was wondering whether maybe Arduino FIO would be a better candidate for the project, instead of the UNO, since it looks like it has all the same input and outputs of the UNO, but has the Xbee socket on board, so will save me some money (I need to build quite a few of them) and also some space. It also is powered by a LiPo battery, which is lighter and more eco-friendly that the standard 9V battery of the UNO.

Yes, the FIO would be a better deal. As AWOL points out, the 9V battery is NOT standard for the Arduino, or even close to a good choice.

Then, I need to talk over the air at distances that might be 1mile or even more. I read that Xbee Pro should reach the mile range. Or is there a way to increase the range? maybe by adding better antennas? or by putting a kind of repeater in between? And consider I'm in Europe, so 900Mhz is not an option

Yes, there are better antennas. They will help with range.

Yes, you could use the XBee series 2/2.5 version to create a mesh network, where communication could involve every node in use to get a message through.

Basically we need to track some vital data while a person walks in a natural trial, together with their location along the trial, and send it real time to a ground station that will visualize them via processing.

What kind of course will the users be on? What does the real-time data offer? Are you stressing the victims (I mean users) along the way? Need to step in if they get to stressed? Or are you just trying to ensure that they keep moving?

4

You might also want to look into the Seeeduino Stalker; it implements a SD card slot, a carrier for the XBee on the board, and includes a jack that 3.7V LiPo batteries will mate with. No USB plug so you'll need a programmer thingy for it.

5

Thank you everybody for the great answers. Here some of my comments

AWOL:

the standard 9V battery of the UNO

That's fightin' talk around these parts, stranger.

PaulS:
As AWOL points out, the 9V battery is NOT standard for the Arduino, or even close to a good choice.

Sorry, as said, I'm pretty newbie, and I always seen arduino being powered by the 9V battery. If using Arduino UNO, what could be a better choice?

PaulS:
Yes, the FIO would be a better deal.

Chagrin:
You might also want to look into the Seeeduino Stalker; it implements a SD card slot, a carrier for the XBee on the board, and includes a jack that 3.7V LiPo batteries will mate with. No USB plug so you'll need a programmer thingy for it.

Will look into the differences between the two devices: from a first look the Stalker would be easier to implement having both the Xbee socket and the standard shield connectors, so I could easily plug both the Xbee and the GPS shield in, while withe FIO I'd have to wire the GPS myself, or with the UNO I'd have to stack GPS and Xbee shields one on top of the other (if that's even possible). And the good think of the Stalker is that it has LiPo and a Solar power circuit charger which is good to recharge the batteries when they are just sitting on the desk waiting for "walkers" to pick them up. And also has the SD slot so the data could be saved here as well. for backup purposes.

PaulS:
You could use the XBee series 2/2.5 version to create a mesh network, where communication could involve every node in use to get a message through.

Will look into this: probably better because I could put a bigger antenna in the base station, but definitely not on the device worn by the "users".

PaulS:

Basically we need to track some vital data while a person walks in a natural trial, together with their location along the trial, and send it real time to a ground station that will visualize them via processing.

What kind of course will the users be on? What does the real-time data offer? Are you stressing the victims (I mean users) along the way? Need to step in if they get to stressed? Or are you just trying to ensure that they keep moving?

That's a long story :slight_smile: But trying to keep it to the minimum: people (let's call them "walkers") will go around a 3-4km loop track. As I said it's an art project, that will be part of a collective exhibition: scattered along this route are the various pieces of the exhibition, made by the other artists, and some other "artificial" stimuli we will add to make sure the walkers are emotionally stressed. We will monitor their vital data and their location, and we'll map in real time their reaction to the various inputs coming from the outside. So, for example, they might like a piece of an artist, and stop staring at it, and getting excited about it. Or might dislike another piece, and will just keep going. This way we create a data visualization with the reaction of the public to the art pieces of the exhibition.
Hope I managed in keeping it short enough :slight_smile:

We are also evaluating some kind of RFID to make sure we know in front of which art piece the user is, but not sure how to implement the thing and if RFID can work also from distance.

Thank you again for all the answers.
Simone

6

Will look into this: probably better because I could put a bigger antenna in the base station, but definitely not on the device worn by the "users".

This will be a problem, then. You can't think in terms of mobile device/base station. The XBee supports bi-directional communication with error handling. In order for one XBee to talk to another, they both have to be able to send and receive data equally. This means that they need the same kinds of antennas, to get similar range.

If you use series 2 XBees, and two XBees can talk to each other through another node, then you can use smaller antennas, but the antennas all need to be the same.

We are also evaluating some kind of RFID to make sure we know in front of which art piece the user is, but not sure how to implement the thing and if RFID can work also from distance.

Yes, RFID can work at a distance. As long as the distance you are talking about is a centimeter or less, or you are talking active RFID ($$$$).

If you have a GPS on each device, won't you know where the victim (I'll call them that since you talk about making sure that they ARE stressed) is? Or will the art pieces be so close together that you can't distinguish?

7

PaulS:
This will be a problem, then. You can't think in terms of mobile device/base station. The XBee supports bi-directional communication with error handling. In order for one XBee to talk to another, they both have to be able to send and receive data equally. This means that they need the same kinds of antennas, to get similar range.

If you use series 2 XBees, and two XBees can talk to each other through another node, then you can use smaller antennas, but the antennas all need to be the same.

I see, so no point adding a bigger gain antenna in the base station (with base station I mean the radio that is connected to the laptop that will elaborate the data and draw them on the visualization), right?
The thing is that the path is a loop, and if we approximate it to a circle of 4-5km of circumference, since all the devices (both walkers and base station) will stay on the circumference, at the furthest point they will be 1300-1600 meters apart. So, in theory it should work, being an outdoor environment the range of XBees Pro should be one mile, which is 1610 meters. But there will be small buildings in between, trees, etc... and probably the range will be reduced.
Probably to help the range I could include other 2 Xbees at 90 and 270 degrees so that in the worst case (all the walkers are in the diametric opposite position of the base station) I have a node every 90 deg.

Another solution would be to get rid of the Xbees, and use GSM. But that will raise the cost of the solution. (One GSM shield costs around 100USD vs the 400USD of the XBee module.

PaulS:
Yes, RFID can work at a distance. As long as the distance you are talking about is a centimeter or less, or you are talking active RFID ($$$$).

If you have a GPS on each device, won't you know where the victim (I'll call them that since you talk about making sure that they ARE stressed) is? Or will the art pieces be so close together that you can't distinguish?

Active RFID: how much will each cost? The thing is that GPS signal might not be optimal (cloud coverage, trees, and so on) and I fear that some pieces might even be indoor. But that will raise the cost of the solution a lot: I'd have to include a RFID reader in each device (20-25USD each) and then add an active RFID tag to each piece... well...let's hope the weather will be nice :slight_smile:

Thanks for your interest in the project
Simone