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Topic: Tracking Animal position and temperature (Read 4907 times) previous topic - next topic


im trying to develop a study on animal behaviour with temperature, so im looking for a easy way to track and log information, then i found arduino.

so this is my ideia:
-Arduino uno + gps shield + temperature sensor.

first question is this viable? the objective is to measure animal temperature along a day and know where he is on a smal area.

if is possible, the second question is, what is better to store the data?a sd card onboard or attache a wifi module.

what's the right direction i should take to stark making progress?

thanks in advance for any help on this, will be very usefull .



How small is "a small area"?
How large is the animal ?

How many hours will you need to track the animal?

Battery power will be a potential problem, especially if you go the wifi way.


first of all, thanks for the help

the area will be 5 ha, if wifi way i have possiblity to creat wifi network for that area
the time and batery is a problem yes, i already thinked on that. it will be sheeps, i hope to get a small box as possible and try to dont go beyond the 0.5 kg or will be heavy for the animal, the best time available, but is possible to change the bateries on midle of the study. the ideia is to repeat along a summer with diferent animal ( sheeps) to try to study a normal behaviour.  ( when go to hor, they go for shadows)

so in your opinion is better to keep the data log on the card's?



I think logging to an SD card will be much easier.

WIFI is going to be difficult for such a large area, and it will use more power.

How are you going to monitor temperature? on the surface of the sheep? Direct unlight could be a problem.


i have 2 option on mind, the first yes in the skin with temperature sensor, the second one using a inside sensor using the sheep back entrace. this depend on values of sensor and programin the logger.

thanks for explanation, i will belive in you and study the Sd card option. ( lots of researching to do )


If you can afford the weight, it might be a good idea to log to both wifi and an SD card. To save power, you could have the Arduino wake the Wifi chip every half hour or so to transmit data. That way if something unfortunate happens to the device (the sheep decides to go for a swim, for example), you don't lose all your data.

Jack Christensen

Wifi is going to be hard on the energy budget! Still need some parameters from you: (1) How many days will the animal need to be tracked, and (2) How often does data need to be collected/logged? Obviously battery life will be better if logging can be, say, every five minutes as opposed to every five seconds.


will depende on the batery, and with the shield anexed ( gps + temperature sensor), like the sheep's are moving im loking for a 1-5 minutes refresh rate, but like you guys say, depende on batery. i only need to get 12-14 hours ( summer day period) after that i can take the data from the box. by what i read depending on the equipamente i think i can manage it with 3-5 AA usual baterys, am i wrong?

if my first test on batery give me alot of hour's, then i increse refresh rate for better conclusions.

thanks for all the help

Jack Christensen

The GPS is the toughest part, they make some that don't use too much power, but they can take a bit to get a fix. If it weren't for that, I'd say two AA cells could go for weeks logging every few minutes. Even so, if less than a day's logging is needed, then it could work even so. How much current does the GPS draw, and is there an estimate of typical time to lock?


using a inside sensor using the sheep back entrace.

Well that adds a whole new dimension, and you'll need all sorts of veterinary advice on that I should think. Not to mention the animal research ethics people getting on your case.

But that aside, is that really feasible? How long can a sheep wander around with a thermometer of some description up its backside? Won't it poop it out long before you get the data you want?  (Unless you get it implanted surgically.)

The GPS is the toughest part

.... Well inserting those rectal probes isn't going to be exactly easy  8)
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Your answer may already be here: https://forum.arduino.cc/index.php?topic=384198.0


Are you trying to measure the temperature of the animal,   or the outdoor temperature ?

Jack Christensen

The GPS is the toughest part

.... Well inserting those rectal probes isn't going to be exactly easy  8)

LOL Jimbo, I definitely had my EE blinders on :smiley-eek-blue:


I also like the idea of the "back entrance"... You will have some very surprised sheep! :smiley-mr-green:

OK, here is how to do your calculations, roughly.

Rechargeable AAs are around 2300mAh. That means, they will provide 2300mA for 1 hour, 230mA for 10 hours, 23mA for 100 hours, and so on. (Actually, it's not that simple, but it's good enough to get you started!)

So. Assuming a 4.5V power supply, that is 3 AA cells in series (4 if you need 6V for a 5V arduino). Either way, that will give you about 150mA for continuous operations over 15 hours. If you double the number of cells (3 in series x 2 sets) you'll get 300mA to work with over the same time, and so on.

A typical GPS shield will draw around 60mA continuous (plus a bit extra for startup, resyncs, and so on). But it depends on the shield and the GPS chip.

So using that example, you have about 90mA to budget for everything else, if you only use a single "string" of cells, or 240mA to budget if you use 2 strings and so on (I hope this is making sense!)

From the specifications, a Uno board will draw (very roughly) 50mA continuous @ 3.3V. I don't know enough about the different boards to know if that's a maximum, or an idle, or what - perhaps someone with lots of knowledge can help us understand the current draws for the different modules in various modes a bit better?

But from my knowledge of other MCUs, it's reasonable to assume that the MCU will draw very roughly 60-120mA if it's running code all the time, using timers, interrupts, and so on. In your case, where all you need is to log data every few minutes, and sleep between, I think you could say much less - in that case, I would average 50mA as a starting budget.

There is a very easy way to get all the numbers, once your code is working. Connect up all the bits, your temp sensor (don't forget your "back passage" sensor!), your GPS shield, and so on, and measure the current drawn. It's as easy as that. That will tell you exactly how much the whole system is using, and from there you can estimate whether you need 3, 6, or 9 AA cells.

So, as a first approximation, let's say the following :
1) GPS Shield : 60mA
2) Uno module : 50mA
3) Flash card read/write : 10mA
4) Temp sensor : 5mA x 2 = 10mA
5) WIFI shield : 50mA, plus 150mA for 10 secs every 10 minutes = average of, say, 75mA

Add it all up : 205mA (roughly) per hour.

So, using a set of 3 or 4 AAs, you will get about 2300mAh/205mA = 11 hours and a bit.

If I were you, I'd use 6 or 8 AAs (assuming the sheep don't mind), that way you will be able to leave it going all day, and maybe all night (if it's cooler, it will use less power).

Does this help? Can anyone think of better figures to use for the different modules/shields?



Well, not exactly. Those numbers seem to assume continuous operation. These are sheep, not aircraft. Put the processor, GPS, radio and all to sleep for some interval. A few questions:

- How often do you need to sample position and temp? Sheep and temp don't move fast. Every minute?  Every 5 minutes? Every 30 minutes?

- What does "5 ha" mean? How big is that in square miles?

- Are the sheep expected to be randomly distributed throughout the area? Or do you expect they will cluster all together in one area?

A few random thoughts...

First, decide what sampling interval you need and plan to shut things down in between. If you only need to sample every 15 minutes, turn the GPS and radio off, put the processor to sleep and only bring everything up to take a sample.

Zigbee or XBee or XPS is a good choice here if the sheep are spread around the sampling area. The sheep can be a mesh network and pass the info along. Even if they do cluster, Xbee pro can give you maybe 6 or more miles line of sight. If the sheep are in a big pasture, you should have line of sight.

If you are able to wait until the end of the day to get the data, SD is fine, but how many sheep are we talking about? If its a small number getting the cards is easy enough. If its 25, 50, maybe more sheep, well the radio is worth the effort. Keep in mind, you fon't need to transmit each sample. Collect the samples in EEPROM and transmit them every x samples, or every y hours, or once a day.

I'm actually working on a very similar system, although for boats. Its very doable, and fun. Maybe some folks from your University's engineering department can persuade a professor to give them some credit for helping you out with design and construction?


Skyjumper, 5ha is 5 hectares (roughly 60,000 square yards). It's how us weirdos in the rest of the world measures areas larger than a couple square metres  :D (actually, I grew up with acres, and I have not the slightest concept of a hectare, although I have to know what they mean!)

Yes, I realise the figures I gave were for constant current, and that sleep mode is much more useful in a project like this. It'll reduce the power drawn by a factor of 10 or more, depending on the ratio of sleep to on time, of course.

Thinking about the OP's project, it would make much more sense to just store the readings on a flash card every 5 minutes or so, and not even worry about WIFI, unless real-time updates were needed. (Heck, knowing sheep, it could be even easier to log just the change (if any) in temperature and position, using integers!).

But worst case, I'm guessing a single NMEA sentence plus a 16-bit integer, 12 times an hour, for 15 hours. No need to worry about overflow. Would it fit in RAM, I wonder?

ANyway, hope this helps.

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