discussion / Sensors  / 3 August 2020

Tiny, Cheap, Modular Ant Sensor Development


Hi! Been working on this project for a decade in various forms on and off, but essentially, I want very small cheap sensors that we can place all over a tree and monitor the insect traffic at multple points (and hopefully multiple trees).

We just got a small bit of funding to work on this project for the next two months from Conservation X labs

Project post here: https://conservationx.com/project/key/wildinsecttrafficsensors

and i am putting project files at this github


I am also kicking off development by leading an interactive art + design workshop at pifcamp (a slovenian hacker camp in the alps http://pif.camp/wearable-interactive-ant-farms-at-pifcamp/ ) . Because it is plague times, they are sharing free workshops and talks all week long! You can just register at pif.camp

for instance tomorrow (Aug 4) at 10am panama time, we are doing a workshop about making tiny ant sensors from SMD LEDs. Please join if you are interested!


also here's a preview of some of the sucess we have had so far with SMD LEDs! https://www.youtube.com/watch?v=gLNYIZaY6bY


we are reverse-biasing some LED's to use as sensors to monitor the ants (Forrest Sims method). Now usually this lets you sense changes in light with an LED, but in generally pretty crapily. LEDs as sensors are ususally not that sensitive compared to things like photoresistors or photo diodes. But on a whim, i tried it with some red SMD LEDs that i was going to use for the workshop (and since the SMD leds are so small even if they were poor detectors, they could still be more "Ant Sized" and useful as simple photo gates in an ant farm or something).

Turns out the SMD LED's seem QUITE sensitive, and can pick up changes in light even obliquely.

The bonus part is that each sensor can function as an LED as well. So you can very easily (and SUPER CHEAPLY) make modulated light sampling arrays of these.

You can take one LED in the array, turn it on. Then all other LEDs sense the light from that particular LED. Next choose a different LED from the array and sample. Now you have the ability to tell small differences in light that might occur from light hitting an ant at many different angles. Finally compare all these readings to a sample where NO LED's are lit up, and you have a very sensitive sensor that is somewhat ambient light independent. You can even take a sample with ALL other leds lit up too!

All the code for doing this on an arduino is all on our github posted above.

The best part is the hardware is super cheap, and if i make PCB's and have them made they are pretty simple, and can get pretty compact. Next i want to toss in a multiplexer and make sure this method still works, and crank up the number of SMD leds.


BTW we are using RED leds because A) They seem more sensitive than other colors, B) many invertebrates and ants often have a hard time seeing longer wavelength, so hopefully it bothers them less C) We can still see them so it makes debugging easier.




This is SO cool, thanks for sharing! Can't wait to see how it turns out! (Also, excellent little ant drawings.)

Do you have any thoughts on how a system like this might expand to help researchers study ants and other insects out in the field? 

I'm an engineer and product designer working on wildlife conservation technology.
Group Curator
WILDLABS Event Speaker

Oh, this looks really interesting. In the past, I've made proximity detectors using 0603 infrared LEDs and photodiodes. This seems like much cheaper way of doing things, especially if the ants are okay with walking over red lights. 

Hi Andrew,

I watched your vid and finally I've got a decent idea of what you're trying to do!  Took a while but what can I say!

I absolutely agree that the machine vision techniques are overkill and that you're on to something here.  It got me thinking about these red line lasers, which project a straight line onto a surface.  These are used in place of chalk lines in construction sometimes.  If you were to project a red laser line onto a tree branch, and focus an image of a length of that line onto a detector (LED), you could pick out the flicker in intensity as ants cross the line.

If you want to get fancy, you can use your optical mouse as the sensor, or a regular camera such as OV7660 for a couple of bucks.  You'd bolt the laser to the camera such that no matter what surface you projected the line onto, the line would show up only as pixels on row 240 (say) of the image. Now it's a matter of watching the pixel values fluctuate.  You can use the usual signal processing techniques to filter out the wrong frequencies.  Use 2 laser lines on 1 camera and you can get ant travel direction too.