Was it the battery pack? Looking at https://www.adafruit.com/product/5579 and https://www.adafruit.com/product/1201 it should be fairly possible to get to a more reasonable size. As an alternative to the leg, having the vibration as something in the collar might be an alternative.

One of the "hmm... things to make" is a lidar detector for things behind a car that then is mapped to an array of the vibration motors that are in the back of a driver's seat - so that you could feel a car passing you.

Arduino fw: https://sensebridge.net/projects/northpaw/northpaw-downloads...

I ride a bike with a Garmin radar detector that tells me when a car is behind me. Adding a vibration motor to it would be neat.

Question - why is either of those options better than a mirror?

I would be wary about replacing a mirror and turning your head with such a system so its main advantage that you don't need to take your eyes off the oncoming road is moot.

As a supplemental system the advantages would include redundancy, lack of a blind spot, and better situational awareness even when you're not planning to change lanes.

because you don't have to turn your head to check; and sometimes you can't hear cars approaching (especially EVs or when there's wind that masks the sound). Mirrors don't provide full visibility and it's also harder to judge the distance and speed of approach (which the radar provides).

yes, exactly this. I thought for sure the radar unit was a gimmick and I'd be returning it, but after seeing so many positive reviews I ordered it to give it a shot. It consistantly tells me there is a car (and how many) well before I hear it.

With a mirror I'd have to be constantly checking which not only takes my eyes off the road ahead, it makes the ride much less enjoyable.

I hadn't considered it until I met a couple this summer who were bikepacking from Seattle to SF. They told me it was one of those items you don't think you need until you get it and then you wonder how you did without it.

It's like blind spot monitoring and rear cameras on cars. I'd been driving without those for decades, but now that I have them I wouldn't buy a car without them.

The Varia radar also connects to the Wahoo bike computer, which is great.

Yes, that's my setup - Varia and Wahoo. I have the original Wahoo from 2015 - 7 years and they're still updating the firmware so that it supports new stuff like radar.

Why not use all of them? Saves having to glance at the mirror consistently, keeping your eyes on the road in front of you, while still having the mirror to check when your other sensor tells you to

>> I ride a bike […] behind me.

> Question - why is either of those options better than a mirror?

Where are you going to put a rearview mirror on a {bicycle?, motorcycle?}? Sure you can have mirrors for the sides for lane changes, but behind you?

It's not like a car, because your person is so much narrower than the structure of a car, less of the rear view is blocked width wise. You just put them towards the outsides of the handlebars and angle them inwards a bit. With careful placement you can have really good awareness of what's going on behind you, both directly and side to side. Oddly not very common on bicycles, but mandated on motorcycles.

I ride a motorcycle and bicycle regularly. I generally don't focus my mirrors on right behind me.

At most, when I'm at a red light, I lean over slightly to make sure the next person is actually going to stop and not rear-end me. Otherwise, while in motion, I have never felt the need for a rearview mirror on any form of two-wheeled vehicle.

I drive a Chevy Suburban (6 kids), its a huge car and can be hard to see my surroundings. When I'm backing out of a parking spot, it will vibrate the left or right side of my seat if a car is coming from the appropriate direction. It'll also do the same if it senses you're drifting into another lane or if you are changing lanes purposefully (blinker on) and someone is in my blindspot. It is extremely convenient

My math teacher would say that the wise Indian parks his horses the direction of escape. Why not back into the parking spot and pull out forward? The overreliance on tech is frightening.

This depends on the law in jurisdiction. For example... https://codelibrary.amlegal.com/codes/pompanobeach/latest/po...

> In all spaces marked for city administered public parking within the city, all vehicles shall be parked with the front end of the vehicle facing into the space provided for parking. It shall be unlawful for any person to back any vehicle into such parking space. No person shall stand or park a vehicle other than at the angle to the curb or into the roadway other than as indicated by signs or markings.

I recall this being the case in Palo Alto for city lots at one time and I believe that San Francisco city lots are similarly ordinanced.

Unless you know the city, it's safest to park "the standard way". No one wants to get a ticket in an out of state city.

Furthermore, there is some "unless you do have a backup camera, the backing into a spot between two cars is more difficult than going in forwards and then using the lot space upon leaving to properly orient."

Lastly, if you are to make use of the trunk of the car, most parking lots are set up to allow easier access when not backed in.

The law discouraging safe driving practice. I don't... even...

I think nose in for 45 degree parking spots makes sense.

There's probably a practicality argument to be made for 90 degree parking to be nose in, because I think it probably results in less blocking of the road is drivers are forced to do the "easier/quicker" front first drive into a spot when arriving avoiding extended time doing "complicated reversing manoeuvres" while other people are trying to get past, and are forced to wait in the parking spot for a big enough gap in traffic (or another driver wanting the spot) before backing out.

> I recall this being the case in Palo Alto for city lots at one time and I believe that San Francisco city lots are similarly ordinanced.

Anecdotally this does not seem to be the case any more, I live in the area and have never been ticketed for backing in. I usually don’t park any other way. You know, in case of zombies and I have to leave quickly.

> Unless you know the city, it's safest to park "the standard way”.

Depends on the city. Which requires…knowing the city? Or at least looking about. So I think that dismisses any idea that one should default to nose-in. Just park like everyone else is doing if you’re so worried. Only thing I’ve seen people ticketed for in SF is not curbing their wheels, which, likely you won’t notice or know about if you’re from out of town.

> Furthermore, there is some "unless you do have a backup camera, the backing into a spot between two cars is more difficult than going in forwards and then using the lot space upon leaving to properly orient."

This is only the case if you have never practiced backing up. It’s actually much easier to make precise movements when you’re reversing, due to the front wheel steering. I’m grateful that this was taught to me by my driving course.

> Lastly, if you are to make use of the trunk of the car, most parking lots are set up to allow easier access when not backed in.

This is true. I park nose-in at Costco.

> […] all vehicles shall be parked with the front end of the vehicle facing into the space provided for parking.

Is there a particular rationale for this rule?

Florida only requires a rear license plate.

You're much more likely to see such ordinances in states that don't require front license plates. https://blog.appwinit.com/states-that-require-a-front-licens...

Note that this is for "for city administered public parking within the city" and doesn't apply to private / commercial lots (which may have their own parking restrictions).

Another low tech way is just to send the kids to watch.

Although this assumes you have a massive car for an actual reason.

I always wished the throttle to be linked to slip sensor on wheels, say push back throttle a bit more when the wheels start slipping and not just wonders why WOT doesn't accelerate as fast as usual all while ECU is pulling power because of slip

> Because of the plasticity of the brain, it has been shown that most wearers gain a new sense of absolute direction, giving them a superhuman ability to navigate their surroundings.

So you would say that this quote isn't exaggeration?

I wouldn't call it superhuman, but it definitely improves it a lot. I think it's helped in general with my sense of direction, but it's a lot less noticeable in an unfamiliar place (if I'm not wearing it).

If I start in a familiar place, then go into somewhere unfamiliar, like a new building, my ability to keep track of cardinal directions is significantly better, which helps keep me oriented to e.g. find my way out of the building.

I was not good at sensing direction until I learned to fly. After I had been flying a year or two, my intuitive sense of direction on the ground became fairly keen, even when I moved to another state or even to Europe.

There are certain places that trip up my sense of direction, especially Spokane, WA. In that city, south feels west to me, and strongly so. Weird.

I have a really good sense of direction.

In the southern hemisphere.

When I travel in the US your "sun in the south at midday" _really_ messes things up.

And when I'm in London and there's no detectable angle to the sun through the clouds, and all medium distance travel happens on the underground, I'm even more completely lost. I have friends in Maida Vale, Edgeware Rd and Marylebone , and I _know_ they're all within walking distance, but there's no way I could dead reckon my way from one to the other. All I know is how to get from there right tube station exit to their houses or nearest pub/cafe...

I have what you might describe as a "spidey sense" about whether a photo depicting a North American coastal scene is on the Atlantic, the Pacific, or something else like Lake Erie. You might have this feeling also.

I suspect it comes from an innate, unconscious comprehension of the highlights and the shadows (since the sun will typically be in the south). And I don't mean the obvious shadows but even the subtle ones.

With practice and perhaps assistance, e.g. North Paw, one could learn to harness the association between light and direction anywhere, not just near huge bodies of water of known direction.

You should play some https://www.geoguessr.com/

Georainbolt is an absolute wizard at this.

In the age of people driving through no entry roads and dirt roads because Google Maps showed them that direction, any intuitive sense of direction and navigation is definitely superhuman in my books.

I haven't used a device like this, but I don't think this is exaggeration. It is well known in linguistics that speakers of languages that use absolute directions are better at determining where north is. People that use the chime feature on their watches to indicate every hour also tend to have a better sense of time. It is also a successful tool for people trying to lucid dream (the "reality checks" are similar in behavior). We also know that one can become better at spatial directions through practice, which is why it is "common" advice to drive around when moving to a new city without a GPS (until necessary). It helps build that mental map in your head (which often generalizes) and tells your brain to pay attention to other correlating features (e.g. I wouldn't be surprised if this North Paw experiment gave users better sense of time with respect to the sun).

It should be no surprise that as one becomes accustomed to one's own environment and the way they navigate it.

Though I think the cooler question is if we can build a phone/smart-watch app that can do this. Is there a way to vibrate the watch in a northernly direction or something like vibrating when the user turns north (deceptively tricky).

GPS in map rotating mode is terrible for spatial awareness. I always keep it in fixed north-upwards mode and I found it does wonders for both navigating streets quickly and for getting to know the layout of wider area.

I worked with the guy that designed this gadget (Hi Eric!), back in ~2009 or so.

It would be really cool to see another version with smaller electronics, flex PCB, etc.

Other features, like connection to a smart phone for waypoint navigation would be neat.

I wonder how well a headband would work.

Having everything integrated into a baseball cap makes the most sense.

Headband would require constant wearing of a hat. I would prefer a belt version.

Same but with a belt, I don’t wear a belt as a rule.

This could easily be a Fitbit type device on wrist.

With the hat or belt, the device is aligned to the body. Wrist mounting would seem to add another degree of freedom. It could work, but the tech would have to be a lot higher.

Why no belts?

I'd love to see a smaller version too! The GPS-tracking-bracelet aesthetic isn't really for me, but I'm still intrigued by the idea.

The key components are a compass and motors, and since 2009 those have been dramatically miniaturized, thanks to the smartphone industry. Combine that with flex PCB and I bet you could fit everything in the form factor of a slap bracelet.

I was thinking the same thing (as in this resembles a GPS ankle-bracelet).

It sounds like the original research used a belt, which to me sounds like a more subtle device to wear:

> The original idea for North Paw comes from research done at University of Osnabrück in Germany. In this study, rather than an anklet, the researchers used a belt. They wore the belt non-stop for six weeks, and reported successive stages of integration.

I feel like a wired belt would raise even more troublesome questions. This situation will be more likely with a belt than an anklet:

https://www.dw.com/en/radiation-student-raises-fake-bomb-ale...

I'm curious how well oriented you felt before. I currently always feel like I can point to north no matter what, so I'm wondering if I'd benefit from this or not? I suppose those abilities get worse when I'm not in a city with an aligned grid or inside a building, like hiking on a trail where you can't see the sun. Still, I'm not sure what I'd gain from this and curious if there's a next level of awareness to attain.

I'll venture a guess that you played a lot of video games with minimaps in your time :-)

Trail navigation is an overlapping skillset. You learn to recognize landmarks, topography, water flow, slopes, shadows, horizons, wind direction, and the sun/stars/moon. Maintaining an internal compass relative to a fixed location is indispensable. If you can do that you should be able to crudely reorient after moving blindfolded through switchbacks.

does the intuitive sense go wrong when you go to a different part of the world? how does that work out?

Not OP, but I've traveled a lot, and it takes me a few days to adapt to the new surroundings. I can't consciously point to what it is that my brain is locking on to, but I can feel 'it' click on, and then I can trust my sense of direction, like I normally do. Before 'it', I can get turned around much more easily than normal.

is this something you’ve picked up from this kind of device, or just something you’ve learned naturally?

As best I can tell, it's just something that runs in the family. My mother (and her siblings) all felt the same way as well, as do many of my matrilineal cousins.

You never said "you wouldn't want to know why..." ?

> and I got tired of questions/comments :)

I'd be very attempted to gruffly retort "murder and racketeering charges" and see how fast they stop being curious.

did you achieve a "superhuman ability to navigate [your] surroundings"? :)