Floating radio buoy for Gotenna Mesh relay!

#1

Check out this awesome 3D printed, solar powered, floating radio buoy! I think this or something like this would make for an awesome gotenna experiment. If anyone else has ideas like this please post links & photos here.

https://pbs.twimg.com/media/DmSGAE_V4AA5nxQ?format=jpg&name=large

https://pbs.twimg.com/media/DmSGAE9VsAAryQY?format=jpg&name=large

https://pbs.twimg.com/media/DmSGAE8VAAAJ8GA?format=jpg&name=large

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#2

Interesting thought but might I suggest some type of mast that elevates the GTM above the surface a bit? I think that would help to improve the signal travel. Maybe a wider base / larger buoy with a 3 or 4 foot mast and the GTM in a weatherproof box at the top? Have the solar panels charge a battery that then connects to the GTM and I think this is a winner.

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#3

That would be a serious upgrade, but I think will be too big for 3D printing.

1 Like
#4

I like the idea! I would agree a few feet above the water seems like it would really help but I would not let that stop you from trying your current design. On a calm day you could get good range. I’m not sure who will be in the area to take advantage of this relay tho?

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#5

I can see a group of fishers using the buoy and goTenna Mesh on all the boats. Silence is an advantage when fishing in most cases. Text is silent.

Then there are fishing competitions. Heck, some colleges sponsor fishing teams that compete against other schools. The buoys and goTenna Mesh would offer some advantages over radio. It’s secure and private, so teams could report in confidentially, etc.

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#6

I suggest including:

  1. a loop to attach an anchor at the bottom.
  2. a method of raising the antenna above the surface of the water.
  3. Most buoys are long with a significant weight at the bottom to keep it upright. It is like a stick on a bottle rocket.
  4. I believe one of the ambassador programs found you needed 5w+ of solar, (5VA+) to power the unit reliably. You will probably need more since all your panels are not pointing at the sun at the same time.

rearden

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#7

That may have been me (I’m actually favoring the 6 W panel in that app now), but that was to power nodes through the winter here in the gloomy Midwest.

When these buoys are most likely to be used would be in the summer, during the daytime. So I’d guesstimate a 3 W panel should be more than adequate for the buoy.

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#8

I think a lot of the power requirement depends on whether or not you have an external battery in play also.
The one I am working on has a small pelican case, a 2200mah external battery, and the GTM. Not settled on the solar panel needed for this yet. I keep kicking around the thought if the external battery is even needed but…8 to 10 hours isn’t enough for a whole day and I’d prefer that it never shut off if possible.

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#9

Right now in New Jersey (IIRC, your state of residence), you won’t need the external battery with long days and lots of sunshine.

Give it two months and things will be different. You will often not have enough capacity to fully charge the outboard battery. By the depths of winter, a 3.5 W panel may not be enough to run the GTM and keep the inboard battery charged. That’s when things shut down and don’t comeback on and you have to climb up to manually reset it. That’s my experience in the Midwest at about the same latitude as New Jersey. While there are large parts of the year that you could get by with less, but best to overbuild in order to ensure year-around performance.

I was using the Voltaic V15, rated at 4000 mAh, and it didn’t sustain power in combination with 3.5 W panels during the winter. I since went to the 6W panel as standard, but also started using 8,000 mAh battery packs, so there’s both more power generated and more capacity to store it. It may be that the 6 W panel in conjunction with a smaller pack with be adequate, but haven’t tested that yet.

The limiting factor for the buoy will be panel size. Instead of a single 6W panel, makes more sense to use multiple 2 W or 3.5 W panels spread around equally to help balance things in the water.

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