Laser scarecrows

[unicornduke]

 It's a thing! 

I'm working on a little one (commercial ones cost tens of thousands of dollars!) that fits in a five gallon bucket. I'm working off plans made by a university researcher for public use but I'm making it better. So to have the laser part of the laser scarecrow, you need something that will shine some light. The ones we used on the actual prototype for work was three inches long and about a quarter size in diameter.

I just ordered a bunch of the robotics parts for the scarecrow and I said, oh! they've got lasers on here. Great! 

I did not check sizing.

y'all, look at this tiny adorable laser!!!!






It is SO tiny and SO cute that I'm not even mad I ordered the wrong thing. 

Comments

[graydon]

The actual laser in a laser pointer about the size of a cell phone camera; the size is so it's holdable and there's a place to put batteries.

That looks like it could be bumping up against the 5 W continuous-power general availability limit.

[unicornduke]

I had figured it was the holding aspect. Makes sense!

Specs say it is 5mW, 650nm and can use between 2.8 and 5.2V. So uhhh something like that I'm guessing.

The plans recommended was 3.6-4.2V 532nm 50mW green wide beam and I obvious misread the milliwatts. I think the wideness of the beam is only so it's visible to birds but it would be a neat experiment to see if the little one scared them off.

[graydon]

Ok, so not much out for the size. Sounds like it's optimizing cost.

Definitely uses less power if it works!

(Though I have to admit my expectation is that there'll be crows on the scarecrow with screwdrivers in a day or so. Only think I know of that works reliably with crows is a great horned owl.)

[unicornduke]

Yeah, it was $6 while the actual one is supposed to be around 21. Eh. I'm getting a deep cycle marine battery to power the thing so it can be out in the field for a couple of days/weeks.

It's actually not the crows we're worried about! Just all the starlings and other songbirds and stuff that go after the blueberries.

The crows go after the corn maze instead.

[graydon]

The Niagara fruit growers tend to go with big mesh tents; pretty much any scaring mechanism just didn't work, or not for long. And the constant banging annoyed the neighbours. (Automated propane things that sound like a shotgun.)

Be interesting to see if coherent light works!

[unicornduke]

Yeah, we visited a grower who used the cannons. Not good. And so far my parents say they haven't seen much issue with bird damage but it's really hard to tell, especially since the plants aren't yet producing most of their fruit at the top. Still young.

There's been some preliminary work done in 2018 showing that these little scarecrows do work pretty well but it's mostly anecdotal with I think one decent study done on farm with sweet corn, but it didn't have a true control because they were desperate for anything to work on all their acres. We know the industrial ones that cost thousands of dollars do. So it's about finding the right mix of circuits and hardware stuff that is easily buildable by some yahoo like me and sturdy enough to survive hanging out in a five gallon bucket suspended ten to fifteen feet in the air while still working.

[graydon]

Hey, if I could learn to solder electronics, I'm sure anyone can!

And lasers are at least something absolutely not found in nature, so there's a chance they'll stay weird.

I find myself wondering -- a quick google isn't informative -- if anyone's taken the "many birds see the earth's electromagnetic field lines, somehow" -- the little magnetic bits connect to the visual cortex -- and tried for a magnetic scarecrow; scramble the navigation system and convince them the blueberries have been planted in the Vortex of Death.

Not likely power efficient, alas.