117 replies to this topic

[SpleenBeGone]

No, was going to do two props. I'm not sure what to do if one gets stuck somehow. 

[SpleenBeGone]

So I found this, which I think is going to really help get things moving in the right direction if I can make it work on my board without the extra sensors. 

 

http://diydrones.com/notes/ArduPilot

[SpleenBeGone]

I'm working on some power problems today, just tossing ideas around in my head.

The board itself will draw 200mA, and I'm worried about powering it during a long time of low or no light, such as if it went though a large storm. I'm thinking having two battery packs might be the way to go. A main power and reserve that will only kick on after x hours of dark.

[Mister Sympa]

Is the weight of the reserve battery going to be an issue at all?

[SpleenBeGone]

I really don't think so for a boat. I should have enough displacement that it won't sit much deeper in the water.

I'm also considering using a keel to keep things more stable in rough weather, and if that's the case, I could weight it with batteries instead of lead. 

[Mister Sympa]

Brilliant! I'd be worried about backup power, and if it doesn't cost antyhing (design-wise), I'd see just how much power I could pack into the little bastard so he didn't get lost or something.

 

I'm trying to visualize this thing, and my imagination keeps wanting to make it like, perpetual and indestructable. You'll be able to explore ICELAND at this rate!!

[SushiKitten]

Oh man, you're actually doing this!

 

How long would the batteries last once sunlight is gone? Maybe set it to every 5% and see how it does on a lake or smaller body of water.

 

I feel like you could use fuzzy logic but I have no idea how, I've never used it before. I tried googling it but all I got were academic papers.

[SpleenBeGone]

Brilliant! I'd be worried about backup power, and if it doesn't cost antyhing (design-wise), I'd see just how much power I could pack into the little bastard so he didn't get lost or something.

 

I'm trying to visualize this thing, and my imagination keeps wanting to make it like, perpetual and indestructable. You'll be able to explore ICELAND at this rate!!

I'm going to pack as much power in it as I can. The limiting factor will really be what the solar panel will charge. Right now I'm looking at 20-25w. 

Design wise, it will be shaped something like this. http://www.nps.gov/s.../images/3_1.jpg

 

 

Oh man, you're actually doing this!

 

How long would the batteries last once sunlight is gone? Maybe set it to every 5% and see how it does on a lake or smaller body of water.

 

I feel like you could use fuzzy logic but I have no idea how, I've never used it before. I tried googling it but all I got were academic papers.

Honestly, I don't have the numbers on the GPS unit yet, but I know it can be powered by a USB port, so that should be max 2.5w power draw. A set of these would run it for about 13 hours, assuming max numbers. I'm really hoping the gps unit uses much less power than that though, especially with a 60 minute ping time instead of 5. 

 

I do plan on tethering it in the pond for a few days and actually test the limits before I do anything with it.

 

There's an absurdly tiny amount of information on this sort of thing, and I'm finding the project to be a lot more complicated than I originally imagined. I feel I can make it work with the things available to me however, and I'm pretty excited to be moving forward. 

[Mister Sympa]

It's cute! It kind of looks like a sampan.

 

http://upload.wikime...ngtzeSampan.jpg

[SpleenBeGone]

Similar, though it will be broader. The idea is to have a deep V hull with a keel to make it the most stable in rough waves. 

This is about the size of the panel I'll be using, to give you an idea of how big it will need to be. http://www.amazon.co...25w solar panel

 

I am however considering using smaller panels as well to fill the empty space up front. I've already sunk some money into this, so I might as well go all out. 

[Mister Sympa]

Oh, absolutely. What is money where there is SCIENCE?

[SpleenBeGone]

Yeah, I was like "Eh, a $20 solar panel and $100 for the gps will be the most expensive things."

Now I'm looking at $60+ solar panels, probably that much or more in batteries, and more than $100 in arduino stuff. 

Science is expensive. There will be ads on the tracker page. >.>

[Mister Sympa]

If you put a wee ad in the bottom here in the name of SCIENCE I bet we wouldn't mind.

[SpleenBeGone]

There already is one. >.>

Pays for the site every month. 

[Mister Sympa]

Oh. Cool.

 

 

 

 

 

'Sup, Adblock. I feel dumb now.

[SpleenBeGone]

And now it's making slightly more every month. 

 

I'm actually planning on using this to advertise the forum though, I'll have a site that allows people to track where the boat currently is, and the path it's taken. Surprisingly, that's the easy part. 

[Mister Sympa]

That's actually really exciting! I admit, I become slightly xenphobic whenever I get comfortable in a specific group of people, but new traffic would be nice.

[SpleenBeGone]

Alright, did a little mathing 

Using the 25w solar panel posted above, I could fit another 5w panel in the curve of the bow. (I really wish I had the resources to get custom shapes printed, lots of wasted space on a boat.)

 

So, 30 watts, and I should be able to get at least 10 hours of light from a day. 300w per 24h, lets say. 4w drawn from the gps and navigation, so that's 56w used. The motors I was originally going to use were 5w each, so I could in theory run them for the full day. This would get really close to killing the batteries though, so I don't want to do that. 

To store 300 watts, I'd need to have around 25 amps @12v, which is actually a surprisingly large battery bank. Now, I'm thinking that I don't actually need something that big because a certain amount of power will be used at a constant. I'm going to say that for the ~10 hours of power generation, everything is running. 14w an hour, leaving us with 16w overflow, 160w by the end of the day. For that we'd need just shy of 14 amps, a little more manageable. 

 

The batteries I linked Sushi are rated at 3400mA, and apparently are pretty good for that, but to be conservative, let's say they're 3amps each. 5 batteries would be enough to capture the remaining energy every day. So lets go ahead and bump it up, 8 batteries would give us 24A, close to the original number we were looking at. Less than two days extra power would keep the battery banks full, and that could run just the navigation and gps for a full 24 hours. 

[Calvary]

Wow that's cool, shame you can't rig it up with a little camera for some sort of twitch.tv live feed or something. I know we talked about that ages ago and it was out of the question but it would be neat haha.

[SpleenBeGone]

Taking apart some hard drives today, I may have found driveshaft bearings. 

 

Also, bonus hard drive platter selfie.