Astro Hacker News - Wooden compass with single red arrow leads people with dementia to their homes

arcastroe |next [-]

Does everyone's phone compass just work reliably? For me, it seems like the most unreliable part of navigation. I traveled to Italy recently and heavily used Google Maps with walking directions, and it was frustrating the number of times I started walking in the wrong direction, due to the compass saying I was facing a direction I wasnt.

If this device uses a similar technology as your phone, then I don't see it being reliable.

estimator7292 |root |parent |next [-]

The magnetic sensor in your phone is actually pretty weak and requires regular calibration to pick out the true magnetic field lines from all the noise.

Your phone has many magnets inside, and structures that can be passively magnetized. Your local magnetic environment changes constantly.

It's a fundamental limitation of the technology, unfortunately. Generally we use GPS location as you move to infer direction and feed that back into the compass routines. It's not great but it does mostly work sometimes

voakbasda |root |parent |next |previous [-]

Have you done orienting in the past?

One of the big tricks is to realize that magnetic north (where your compass points) is usually not the same as geographic north (where maps are drawn). The adjustment is local; here, I think magnetic north is 7 degrees off from north.

In the US, the USGS topographic maps contain the required adjustment for the covered area. Not sure about Italy.

integralid |root |parent [-]

I don't think that's it. For me sometimes my phone compass is (roughly) right, but sometimes points in a completely wrong direction, for example 90 degrees off. It calibrates after a while when I start walking but I guess this is what OP had in mind, not a few degree difference.

jiggawatts |root |parent [-]

iPhones can regain the compass fix if you move the phone along a figure eight path while holding it flat and level. Worked pretty well for me in the past.

peterbecich |root |parent |next |previous [-]

Thoughtful concept but agreed. I.i.r.c the phone can assess the inaccuracy of the compass and prompt the figure-8 movement. But that is not practical here.

scotty79 |root |parent |previous [-]

I'm fairly often doing figure-8 with my phone in front of myself to realign the compass.

sejje |next |previous [-]

I like this, but of course the location it points to should be programmable at any time.

Then it's useful for everyone without dementia as well, and a bigger market is better.

For me, this is the perfect motorcycle navigation. In fact, I use an app that turns my smart watch into exactly this product--an arrow pointing to my destination at all times, no other information (distance might be nice though)

Actually, if it's for people with dementia, I think it should have a couple words on it. "Home", an actual arrow, and a distance. Two of those could be static additions, if the designer will allow their minimalism to be sacrificed for the actual goal of the product.

kotaKat |root |parent [-]

> motorcycle navigation

Have you seen the Beeline app/hardware? Pretty much a similar concept of 'follow the arrow' to get to where you need to go. https://beeline.co/

> programmable at any time

I assume a caregiver application could reprogram the location pushpin as a feature.

sejje |root |parent [-]

I hadn't seen Beeline, but it looks sweet. I may pick one up.

I always wonder if I'm just buying future ewaste, though. Looks like it requires their app, which requires their live servers. One acquisition away from end-of-lifed.

kotaKat |root |parent [-]

The Beeline app lets you start navigation and 'simulate' a Beeline on screen, if you'd like to try one.

cdaringe |next |previous [-]

Id like to see a DIY variant! A couple of radios and homebase software. Could be a fun one to try an emulate.

oniony |next |previous [-]

Great, I wish you all well looking for this device — in addition to their keys — for two hours every couple of days.

After several weeks I once found the lost TV remote in the Scrabble box. However it was short lived: we had to replace it at least another five times over the next couple of years.

tsol |root |parent |next [-]

Ah good point. I think the solution to this is simple. A second, smaller compass that points towards the first one

roughly |root |parent [-]

Yeah, but where do I keep that one?

cardiffspaceman |root |parent [-]

Body modification?

cdaringe |root |parent |previous [-]

Something something something built in airtag-like finder?

cluckindan |next |previous [-]

Remembering how ”easy” it is to navigate with such an arrow in GTA, I would expect this to fail in unimaginable ways.

It could point at a river instead of the bridge over it.

It could point at an airport instead of the route around it.

It could point at a cul-de-sac, a dangerous neighborhood, a construction site, etc.

scotty79 |root |parent [-]

That depends on the implementation. It could use GPS and map to trace walkable path to destination and point the needle in the direction that you need to move towards to follow the path.

simulator5g |root |parent [-]

Except this doesn’t work on smartphones. Have you ever tried using GPS? It doesn’t understand what direction you’re facing unless you’re steadily moving forward.

estimator7292 |root |parent |next [-]

That's because GPS is not directional. It's a positioning system. Direction can only be inferred as the difference between locations.

GPS fundamentally has no way of determining your direction. It was never designed for anything other than giving you a single fixed 3D location on the Earth's surface.

robocat |root |parent [-]

Rubbish: from first principles it is obvious that direction can be calculated. You are correct for phones, which have omnidirectional antennas that can't calculate direction (also built up areas with multipath would make direction finding difficult).

  Marine navigation systems are the most familiar example. Many boat GPS units advertise “GPS compass” or “true heading at zero speed.” . The antennas contain two GNSS elements, fixed a known distance apart, and the direction is found using phase comparison: they look at the tiny difference in arrival time of the same satellite signal at the two separate antennas.

Either (a) don't answer if you don't know what you are talking about or better (b) double check your "facts" (using Google or AI) before answering.

scotty79 |root |parent [-]

You just basically confirmed what the previous commenter said. GPS is not directional. You need two of them placed some significant distance apart (think ship length, not smartphone length).

When you have two points determined with high enough precision you obviously have a direction and even orientation.

Your comment could have been just that. Useful information many people could find interesting. Instead you decided to sprinkle it with bile.

robocat |root |parent [-]

You are doubling down - I do find your misinformation to be interesting.

Have a look at images of the antennas:

https://duckduckgo.com/?q=%22GPS+compass%22+antenna&ia=image...

I do apologize for liking brutal facts - I am an engineer type.

I clicked the Furuno antenna since it looked sexy - blurb:

  SC-130 features a Tri-sensor antenna that provides a high system accuracy for the heading of your vessel [for Autopilot,  berthing etcetera.]. 0.25°rms

Fist principles: I think wavelength of L1 GPS frequency is about 0.2m - the same order as smartphone length. A ship length baseline using phase would need precise engineering and would not work for satellites absolutely perpendicular to the ship (making it less ideal).

Calculating phase difference only needs a single satellite visible, so I would guess directionality can be precise in built up areas even where location is harder to fix. although I'm assuming multipath can be filtered out.

scotty79 |root |parent |previous [-]

It's because maps apps don't trust builtin compass. Which is reasonable since it fairly often loses calibration.

kelseyfrog |next |previous [-]

How do they remember to take it with them when they leave their home?

thisrod |root |parent |next [-]

People with this level of dementia won't be able to live independently, and there will be someone else to check that.

DonHopkins |root |parent |previous [-]

[flagged]

DonHopkins |next |previous [-]

Hopefully it computes a pedestrian safe path to your front door and points that way, not as the crow flies, otherwise it could walk you over a cliff or into a pond.

NedF |previous [-]

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