Oct '14
2

Some research indicates that WiFi and other wireless data transfer technologies can cause disruption with bees. We are exploring ways to limit/prevent the signal from interfering with bees.

Please share any research into WiFi etc. effects on bees, and any research into how we might limit or prevent these effects.

AaronMProject Co-Founder
Oct '14

This video demonstrates how to prevent radio frequency interference (RFI).

Digikey: RF Shielding: The Art and Science of Eliminating Interference

"Figure 1: Designers have a wide choice of EMI shielding products, from simple shield boxes such as offered by Laird Technologies, Würth Electronics, and FotoFab (left to right, top row), conductive films from TDK, and 3M, and conductive foam gaskets such as offered by Laird Technologies (left to right, bottom row)."

AaronMProject Co-Founder
Oct '14

See some further ideas here:

  AaronM
Jan '15

Component shielding will definitely be good to do at a minimum. A fully metallic enclosure may even be preferable.

But before that it will be useful to measure unintentional emissions to see what frequencies are radiating from the device in full operation.

From there, filtering capacitors / resistors / ferrite beads can be used to try to squash the frequencies before they even radiate off the board (this is the part many engineers refer to as black magic because it's not always straight forward). If testing a PCB rather than a breadboard, keep in mind that the solution MAY require turning the board to incorporate the necessary changes.

An enclosure would be the final assurance that the unwanted RF won't affect the bees after you're sure the electronics are already as quiet as possible. Often, people will skip an enclosure once they've lowered emissions enough to comply with international technical standards (CISPR 22, FCC Part 15 Subpart B, and many others). In this case, it is unknown how bees are affected by RF, so the approach should likely be to make the electronics as quiet as possible. So a metallic enclosure would be prefered in addition, I think.

1 person liked this.
  trizcs
Jan '15

That's a good idea! I think @AaronM 's idea about creating an RF barrier on the box to direct WiFi towards the router is an essential concept. Perhaps a combination of this shielded sheathing material for the boxes as well as a conical metallic shape around the WiFi antenna/sensor to make it more directional and point it away from the hive.

1 person liked this.
AaronMProject Co-Founder
Jan '15

Hi @farkmeil - do you have experience testing for RF signatures? Thanks for joining the community.

  farkmeil
Jan '15

Does the board really need to communicate over WiFi? Maybe I don't get the idea but if I wanted to be sure that RF does not affect the bees I would move all the RF sources outside the hive and then additionaly shield it. The best I can think of is to connect the sensor kit with a WiFi access point with UTP cable. You can then move the WiFi a 100 meters away from the hive. No need to worry about RF noise, shielding, etc.

  AaronM
Jan '15

Yes, I do.

I can offer the community to run "informal" tests in my free time under the category of educational pursuit. Official/fully accredited testing would need to be quoted and go through the proper channels if it were needed for regulatory purposes.

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  jakub
Jan '15

@jakub What you suggest would be the ideal approach (but perhaps go as far as shielded cable -- E-net can be very noisy in the 30MHz area on radiated measurements)

While intentional emitters are more likely to cause problems due to the transmission power, there are still, very likely, unintentional emissions from the circuitry that would need to be addressed.

  farkmeil
Jan '15

The would be awesome @farkmeil - we really appreciate it and I think the bees will too smile

We'll need some time to get you the final kit, but if the offer stands we would love to take you up on it when we're ready. In the meantime, I think exploring options for a cheap and easily made cage are good. As you can see here we've got a sensor case underway (currently acrylic). Would it be possible to pad a case like this with the foil posted above?

Any ideas on how DIYers could create a decent wifi protection for the bees would be radical - some people will be making these sensors themselves and wont necessarily be able to access the tool and materials we have.

Jan '15

By the way:

What got me thinking about RF/Bees/Colony collapse was a documentary about dung beetles using UV to navigate. While I've always understood that insects and other animals see different or wider spectrums it had never occurred to me that RF may not affect all organic life in the same way. While the RF we commonly use today in our electronics is not harmful to humans--
(Yes, I really believe that it's not. SARS tests, albeit required for devices like mobile phones, are on the whole useless--IMO. I am also VERY wary of claims that your city adding an RF transmitter to your home's gas gauge is making your family sick.) -- that it could possibly be affecting wildlife differently.

While I realize UV and the RF spectrum we are concerned about are not even close, this IS what got me thinking about it.

Excited to be part of the community.

  farkmeil
Jan '15

@farkmeil @trizcs Yeah I know that but doesn't the board emit any noise? I just keep in mind that we do not know much about how the RF disrupt the bees. That is why packing all the electronics with a WiFi antenna into the hive even if it's shielded and measured (what is the RF minimum for the bees really?) sounds like crazy when there are other easy ways to solve the problem for example by placing the board into the ground and only leaving the sensors in the hive. And one another question is is the WiFi really critical for that project (I do not mean the fanciness)? What about people not having their hives in the backyard. Do they need wifi at all?

1 person liked this.
  trizcs
Jan '15

Cool progress. Yes, foil will work. You can even use copper laden paints to serve the same purpose.

As for DIYers, A bit of tin foil in the right places can do everything you need. It's very common in the troubleshooting stages of electronics development to pull out a roll of Reynolds Wrap and start experimenting. The only reason such methods are not employed in the final product is that pulling out the tin foil isn't generally a manufacturable solution, nor is it very cost effective. Often a square foot of foil is more expensive than a smd capacitor put in the right place.

We will know more further on where and how to apply the foil and could post a video perhaps for DIYers consumption.

If they want to employ it now, however, even one sheet thick of foil is enough to block most emissions.

Jan '15

So let's just do it. I see a lot of things to be done in the project and going into the wifi at this point sounds like insane because instead of solving the main problem a new one is generated. I could understand this if there were no alternatives but there are safe ones just at hand.

1 person liked this.
AaronMProject Co-Founder
Jan '15

The plan is to a) shield the sensor case, and b) use a directional antenna mounted outside the hive to send and receive data, which focuses RF transmission to a single point. We're also including a SD card with the option to turn off wifi altogether, although the beekeeper then needs to manually download the data from the SD card from time to time.

Wifi allows for realtime data monitoring in order to participate in hive activity without latency. It's an option we're exploring, as this is quite clearly a science project, not a finished product. Since all source code is openly available, everyone is free to pursue development however they think is best.

1 person liked this.
Jan '15
1

Just to clarify there are two RF issues to address:

1 - Reducing the effect that a 2.4GHz WiFi transmissions may have on the hive
2 - Reducing all unintentional emissions (generally 30-1000MHz, but sometimes well below 30 MHz) due to the unknown effects they may have on the hive.

Do keep in mind that the addition of WiFi adds considerable utility while it's negative effects are presently unknown. So the goal, as I understand it, is to reduce its effects, but not necessarily omit the technology on the grounds of possible adverse effects on the hive. Is this a valid assumption?

One solution one might employ would be to use a low power transmitter **like BLE on the unit near the hive then receive that transmission several meters away and convert to E-net/WiFi. This would significantly reduce RF issues, as the RF power is reduced considerably over increased distance (see Inverse Square Law).

**(emphasise LIKE-I think the Bluetooth council wants ~$10K per product. An open source protocol would be desirable, of which I think a few reside in the Bluetooth umbrella)

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