discussion / Software and Mobile Apps  / 7 December 2018

Researching most affordable GPS chips with sensor capability

Hello! I'm conducting extensive research trying to find the most affordable GPS chip on the market now, capable of also having a sensor chip that senses and measures body temp and/or heart rate of large mammals. I'm working on a multi-phase program involving inserting these chips into ear tags for livestock in predator dense areas for consercation of predators and livestock in predator areas. MUCH more happening with this project but this is a start. Would love to hear from someone. And this is an amazing community. 

This is so amazing...thanks for good work. Am a wildlife health and management student from Makerere University, Uganda and currently interested in such technology...hope you could help me connect with you as i look for to be mentored by great people like you. Regards from Uganda

Hi there Malou!

You can find several cheap chinese modules like: 

You also have some integrated with micro-controllers so you can actually embed some logic inside, like:

But to me, the main issue here would be on which communication technology do you use to relay this gps/sensor frames to the server (cellullar technologies, LPWAN-like technologies (LoRaWAN)). 

Also GPS = devices will be power-hungry, so it will be also a challenge to get a decent battery life in a compact device.

But those challenges are what we are here for! If you need more help let me know :)


Hi Malou, 

Interesting question - I think some members of our HWC Group might be interested in this thread, so would you keep it updated as you progress through the project? I've not much to add on the technical side, but I'm commenting mainly to cc in a few people who might be interested and are working in the same sort of space. 

cc-ing in @Femke+Hilderink and @NJayasinghe (our group managers) so they're aware of this thread. 

@VAR1 - Malou might be someone to talk to about your tech for rewilding conflicts question? 

@Damian - this might a project to keep an eye on, given commonalities with what you're doing with mixed use at ol pejeta? 






Hello Malou

I hazard the guess that what you are looking for is already available for livestock monitoring, so I would look in that direction unless you want to re-invent that wheel. I admit I am not 100% sure what is out there as I am working on something unrelated. Homemade tags may be cheaper but don't underestimate the effort and experience required to make something reliable and robust.

Reliably monitoring body temperature and heart rate may also be more difficult than you expect. I looked into this some time ago for birds such as golden eagles and discovered that the most reliable option required attaching a sensor onto the skin. I then decided that I would have to do without this and moved on. I am in no way an expert on this and others may know much better so don't give up quite yet. Again, there may be ready-made solutions in the livestock tracking market that do these types of measurements already.

Anyway, I can offer you a few details on GPS components I have come across that may be of interest. Please note that although these components are on my tracker prototype, this is still under development and I cannot yet say how well they perform. But their technical details looked good enough to give them a try for my project.


- certainly not the cheapest, GBP 10 bought in single units, cheaper in bulk;
- stores GPS satellites' almanac and ephemeris data onboard and can interpolate future trajectories. This means that the module has to be switched on only once in 48 h to get all the satellite data (typically takes 45 s) and then fire up only for a few seconds to get a position fix. The key benefit of this is energy conservation, which on most tags is important.
Data sheet: https://www.u-blox.com/sites/default/files/EVA-M8-FW3_DataSheet_(UBX-16014189).pdf
Source: https://www.digikey.com/product-detail/en/u-blox-america-inc/EVA-M8M-1/672-1112-1-ND/9818030


A very small and lightweight GPS antenna, much more so than the usual ceramic patch antennas. If weight and size are an issue then this may come in handy.
data sheet: http://www.proant.se/files/user/Application%20note%20-%20OnBoard%20SMD%20GNSS%20rev%202.0.pdf
Source: https://www.digikey.co.uk/products/en?keywords=1532-1000-1-ND


A hint for more inspiration and sources of useful information on lightweight and energy-efficient electronics: websites on remote controlled model aircraft and amateur weather balloons.

It would be useful if you could post here a summary of your results on the GPS module search, once complete, for the benefit of those looking for the same details in the future.

Good luck !