"In 2025, Garmin announced that they would end their certification for ANT+ devices, blaming changes in wireless communication regulations. This is likely to lead to future devices dropping ANT+ support in favour of BLE."
That's interesting. As the article says, ANT's main use case is in commercial gym equipment. What the article doesn't say is the reason: it excels at gathering data for "group fitness". ANT is a connectionless protocol so in a situation where you have two dozen transmitters and you need to get data from all of them, your receiver simply has to listen and record whatever devices it sees and let the user software (possibly managing a gym leaderboard for a spin class) decide which ones to track.
Contrast with BLE where you would have to make a connection to each device. The overhead of connecting and disconnecting, in addition to being power-prohibitive, takes too long. Some manufacturers have workarounds to enable use of their BLE products in a group fitness environment, but they are pretty much lacking.
It'll be interesting to see how the problem is solved if indeed ANT+ does go away.
BLE could do that too via advertising packets. I don't know if any devices actually do though.
Also the connection process isn't power-prohibitive for BLE, and it doesn't have to take a long time. It's just that most Bluetooth software stacks suck balls. Basically only Apple's is good.
As I recall BLE only supports hosts connecting to 7 peripherals simultaneously which is a bit rubbish, but if you're a gym with some custom ANT+ receiver you can definitely get a custom BLE receiver that can connect to more devices (assuming someone makes such a thing).
Many devices put the data into the Manufacturer-specific part of the advertising packet. It's a workaround. The problem is that it's non-standard so if you're a provider of data management for group fitness you have to have custom code for each manufacturer (and sometimes different devices from the same manufacturer). And it's especially fun when the manufacturer's published data spec doesn't match what the device actually puts out!
I don't know how difficult it would be to connect, grab a bunch of data and disconnect from 24 BLE devices in a one-second period, which is pretty much what you'd need to be an effective workaround for ANT+. In a competitive environment, data from each device changes very rapidly.
The ANT+ article was really interesting and it seems like a real shame that it's going the way of the dodo. Now I know what those little status symbols are on some of the gym equipment. Seems like a great protocol for the use case, but nit massively surprising it couldn't survive on that niche alone. Shame.
My impression was part of the issue was ANT is a proprietary Garmin protocol and so never really gained traction or imprint beyond those devices. Without meaning to sound too critical or supportive of BLE, I think something more open would be better for that area anyway.
> refrigeration. Samples being shipped to the lab and reagents shipped out to clinics were both temperature sensitive. Providers had to verify that these materials had stayed adequately cold throughout shipping and handling, [...] Moreover, Stevens imagined that these sensors would be in continuous communication. There's a lot of overlap between this application and personal area networks (PANs), protocols like Bluetooth
If I were the president I would install this on random doors in the White House as a prank. It would be fun to watch the NSC fumble for their phone when walking into the oval.
Can someone explain how communication can take place using only magnetic fields? I thought that communication requires electro magnetic waves which require an oscillating electro magnetic field.
A changing magnetic field will always induce an electrical field and vice-versa. Even just moving a magnet with your hand will generate an electrical field. Near-field effects of an antenna still involve this interaction.
The key to the resistance of very long wavelengths of EM radiation (or equivalently, very slowly varying electric/magnetic fields) to attenuation when traveling through a metal is the nature of the way metals expel electric fields (they don’t generally block magnetic fields). When you apply a static electric field to a thin conductor, electrons will be pulled away from one side and toward the other such that the field inside is zero. However this migration of charges will actually result in the electric field on the far side of the metal being nearly the same as the field on the side closer to the source!
If the wavelength of some EM radiation is much longer than a metal obstacle is thick, the fact that the electric field is excluded from the interior of the metal won’t matter much. Even if the metal wasn’t there, the electric field strength wouldn’t vary much over that distance, and on the other side of the metal the induced charges will restore the roughly “correct” field. Since the magnetic component won’t vary much over that distance either, the fact that there’s no varying electric field inside the conductor to reinforce the magnetic field won’t significantly attenuate it.
If you’re familiar with Faraday cages, this will sound all wrong. Isn’t it long wavelengths they can block, and short wavelengths they can’t? This true when dealing with EM radiation in the “normal” radio bands and higher, but it turns out their ability to attenuate radiation falls off in the other direction too (once wavelengths get extremely long). When dealing with EM properties of materials, there are a huge number of different effects that apply in different circumstances, and it’s easy to forget one and confuse yourself.
I went into a slight hunt for more knowledge after reading this, and long story short you need to search NFMI (near field magnetic induction)[1]. As far as I can see from my limited reading the main use case of the tech is nfc (near field comm) and true wireless earbuds.
The US is the largest market for firearms, so the NRA can use the threat of boycotting a manufacturer within the states to prevent the technology gaining traction elsewhere.
To profit, they would first have to sell the goods. Who is actually in the market for a smart gun? Consumers aren't, surely. There is virtually no upside to your gun tracking you, at your own expense of buying a more complex piece of tech to boot. So that leaves something like (apparently) New Jersey where the government would compel purchases of smart guns because they were interested in the tracking. But eg. China simply don't allow citizens to purchase guns period. There may be some application to applying it to state-owned firearms to track military and police usage, but deploying that at Chinese scale would be an extremely expensive endeavour for what appears to be a solution in search of a problem. Not to mention the biometric lock concept, if implemented, is introducing an entire new axis of unreliability to a life-or-death tool.
Gun owners in the US probably wouldn't want their gun to be used against them in a home invasion, or by their child at a school. Seems like that could be a large-ish market. Especially if you can lobby regulators in favor of making it a requirement for all or some people.
You are right that gun owners wouldn't want those things, but they are unlikely to want a smart gun as a solution to those things.
They want the gun to be available to them, and not be under duress to use a fingerprint reader or pin pad or RFID ring to do it.
Responsible gun owners keep guns out of children's hands by locking them up or supervising them, and irresponsible ones aren't going to want to pay extra for smart features.
I think there's a very narrow range of smart features, something like a gun that is unlocked when removed from a holster, but locks up if it is dropped or grabbed, that might be interesting. That makes having the gun taken from an officer less of a threat, which might have an institutional appeal. Give it a 10-hour maintenance mode so that it can be used as a "nightstand gun" while automatically being locked if left idle for longer, and it would basically meet the needs of police both on and off-duty.
In my personal experience gun owners want mechanical foolproofness too. They want something that's not going to lock up or fail or discharge at the wrong time. Smart features just add a layer of complexity with fail possibilities to address a problem that many of them would prefer to be addressed differently anyway.
I think a country like Australia could be a good starting point for smart guns. Yes, not a very big market-around 8% of US population, with significantly lower rates of gun ownership-but culturally more open to gun control, with a much weaker gun rights lobby, and a marked political tendency towards surveillance and “nanny state” regulation
IIRC Australia doesn't have legal frameworks for gun ownership for the purpose of self defense, and there's no great implementation of smart guns in the first place.
A smart gun is like an AWS authenticated motor twisting ballpoint pen. Just no one ever seriously pays for such a thing, and it has not even been seriously made if it ever was actually conceived. Making it a requirement is basically out of question.
> Making it a requirement is basically out of question
Why? If there’s the political will, it is doable. There are Australian gun manufacturers (e.g. Lithgow Arms, owned by Thales)-and if none of them are willing to cooperate, the government can always start their own gun manufacturer. Indeed, Lithgow Arms was founded in 1912 as a government-owned arms manufacturer, and remained in public hands until the Australian federal government sold it to Thales in 2006.
Same reasons as why things like Clipper Chips isn't happening. It completely lacks technical basis, and even political consensus gets sketchy quick.
Post-war Commonwealth nations are generally bad at gun designs as well - UK tried once and produced an infantry rifle that will(not could) seriously injure its user if held and fired in left hand. So even if forced, the approved gun will be more of a theoretical product, and the smart gun mandate will just be a less politically viable alternative to total firearms ban.
The tech just isn't there; hand-held guns don't benefit from a computerized firing system at all. So any smart feature on human sized guns and less will be totally removable addons, and that completely defeats its purpose.
Many tanks and planes do have smart guns. Electronic firing control with additional software features that impede firing are beneficial and totally fine at that scale.
That's just a scope. Comes right off and the gun reverts to a regular M4.
Most(though not all) other smart gun attempts work in a similar fashion; the host gun works exactly as it were, except an extraneous metal bit inhibits firing. If the bit was removed or held down, it reverts to the original host gun and fires normally. As such, the extra bit is literally extraneous, irrelevant to the gun's working.
This. There’s many countries that allow civilians firearms (e.g. Canada and much of Europe), but generally for hunting purposes and thus more likely to be rifles and shotguns than concealable handguns.
Most of the world doesn’t need that whole setup because:
- Our cultural baseline around firearms is completely different. Countries like Denmark, Sweden, Finland, Switzerland, Austria, and the Czech Republic have plenty of guns at home - and historically, a lot of them were actual assault rifles, not “looks-spicy” semiautos.
- We treat guns like weapons. They live in safes, not nightstands, and kids get taught safety early, the same way you’d teach them not to put a fork in a power supply.
The Swiss do have a lot of guns at home. However, you cannot carry (or even transport guns that are not discharged). Just take them at a shooting range - a popular pastime for Swiss people.
The correct answer is - all the designs so far aren’t great.
The military would love a smart gun to cut down on accidental discharges. Cops would love it to stop weapons being used against cops.
The issue is that it has to have a very high reliability (you don’t want it to fail to fire while a suspect is shooting at you). And not much point if it only works “sometimes” with unauthorized users.
2.5 million years ago, a friend of mine
Made a tool from a stone and defended his tribe
It's technology, sorry for the technical term
It's a wheel then a fire and the rest is a blur
RuBep? As ever, the fastest way to get a correct answer on the internet is to post an incorrect one:
> The Institute of Electrical & Electronics Engineers Inc., the international governing group for such technology, has designated P1901.1 as the technical designation given to the RuBee technology, which was named RuBee by Visible Assets. "There is no real reason we named it RuBee," said Mr. Stevens. "It actually was named after the song 'Ruby Tuesday.' It just sounded good."
> Long ago I wrote about ANT+, for example, a failed personal area network standard designed mostly around fitness applications.
I didn’t know ANT+ was “failed”, I use it all the time with my Garmin products. It’s cheap and it works better than Bluetooth.
I have ANT+ cadence and heart rate sensors. Lights, camera, Varia radar and power meter.
Some of that can be done with Bluetooth but realistically not all at the same time.
Anyone that’s run a smart trainer in a group with others will know that ANT+ is generally more reliable than Bluetooth too.
Apple refuse to support ANT+ so I need a dongle for my Mac and it’s the reason I don’t have an Apple Watch. No biggie.
"In 2025, Garmin announced that they would end their certification for ANT+ devices, blaming changes in wireless communication regulations. This is likely to lead to future devices dropping ANT+ support in favour of BLE."
https://en.wikipedia.org/wiki/ANT_(network)
I believe that's what the author was referring to when describing it as failed, but yes, this could've been worded better.
That's interesting. As the article says, ANT's main use case is in commercial gym equipment. What the article doesn't say is the reason: it excels at gathering data for "group fitness". ANT is a connectionless protocol so in a situation where you have two dozen transmitters and you need to get data from all of them, your receiver simply has to listen and record whatever devices it sees and let the user software (possibly managing a gym leaderboard for a spin class) decide which ones to track.
Contrast with BLE where you would have to make a connection to each device. The overhead of connecting and disconnecting, in addition to being power-prohibitive, takes too long. Some manufacturers have workarounds to enable use of their BLE products in a group fitness environment, but they are pretty much lacking.
It'll be interesting to see how the problem is solved if indeed ANT+ does go away.
BLE could do that too via advertising packets. I don't know if any devices actually do though.
Also the connection process isn't power-prohibitive for BLE, and it doesn't have to take a long time. It's just that most Bluetooth software stacks suck balls. Basically only Apple's is good.
As I recall BLE only supports hosts connecting to 7 peripherals simultaneously which is a bit rubbish, but if you're a gym with some custom ANT+ receiver you can definitely get a custom BLE receiver that can connect to more devices (assuming someone makes such a thing).
Many devices put the data into the Manufacturer-specific part of the advertising packet. It's a workaround. The problem is that it's non-standard so if you're a provider of data management for group fitness you have to have custom code for each manufacturer (and sometimes different devices from the same manufacturer). And it's especially fun when the manufacturer's published data spec doesn't match what the device actually puts out!
I don't know how difficult it would be to connect, grab a bunch of data and disconnect from 24 BLE devices in a one-second period, which is pretty much what you'd need to be an effective workaround for ANT+. In a competitive environment, data from each device changes very rapidly.
Aha! OK that's sad news but makes perfect sense. Thanks.
The ANT+ article was really interesting and it seems like a real shame that it's going the way of the dodo. Now I know what those little status symbols are on some of the gym equipment. Seems like a great protocol for the use case, but nit massively surprising it couldn't survive on that niche alone. Shame.
My impression was part of the issue was ANT is a proprietary Garmin protocol and so never really gained traction or imprint beyond those devices. Without meaning to sound too critical or supportive of BLE, I think something more open would be better for that area anyway.
As far as I’m aware most manufacturers of fitness equipment were supporting ANT+.
ANT+ (vs ANT) is proprietary but licensing was free and large part of the spec are open.
There were definitely a lot of manufacturers supporting it. Not just on watches and GPS units but also on some phones.
> refrigeration. Samples being shipped to the lab and reagents shipped out to clinics were both temperature sensitive. Providers had to verify that these materials had stayed adequately cold throughout shipping and handling, [...] Moreover, Stevens imagined that these sensors would be in continuous communication. There's a lot of overlap between this application and personal area networks (PANs), protocols like Bluetooth
I like the low-fi solution personally:
https://www.ipack.com/warmmark-temperature-indicator-short-r...
https://www.ipack.com/coldmark-temperature-indicator-10c-50f...
That will tell you if the item is spoiled, not alert you that it is on its way to being spoiled. Very different use cases and outcomes.
> I have at least a few readers for which the sound of a man's voice saying "government cell phone detected" will elicit a palpable reaction.
Can this be recreated as an audio clip for jumpscaring former govt employees?
Why not just rip the audio file off? Would make for a funny DC request
Edit: On second thought this could be an OPSEC problem. Sorry but I don’t know if anyone can help you :(
If I were the president I would install this on random doors in the White House as a prank. It would be fun to watch the NSC fumble for their phone when walking into the oval.
I bet the tts voice is public and something made by AT&T in the 80s or 90s.
Why TTS if it's just a static phrase? More likely that a random developer recorded that sentence and the wav is hardcoded in all the units.
It might be that the law around voice recordings are not as simple as we might imagine.
> the firearms lobby is very influential on police departments, as are police unions which generally oppose technical accountability measures
A lot of what’s wrong in surprisingly few words
I love this blog author's writing style. It's very engaging, and draws me into subjects I would otherwise have minimal interest in.
Definitely gonna check out some more of their posts later.
Can someone explain how communication can take place using only magnetic fields? I thought that communication requires electro magnetic waves which require an oscillating electro magnetic field.
A changing magnetic field will always induce an electrical field and vice-versa. Even just moving a magnet with your hand will generate an electrical field. Near-field effects of an antenna still involve this interaction.
The key to the resistance of very long wavelengths of EM radiation (or equivalently, very slowly varying electric/magnetic fields) to attenuation when traveling through a metal is the nature of the way metals expel electric fields (they don’t generally block magnetic fields). When you apply a static electric field to a thin conductor, electrons will be pulled away from one side and toward the other such that the field inside is zero. However this migration of charges will actually result in the electric field on the far side of the metal being nearly the same as the field on the side closer to the source!
If the wavelength of some EM radiation is much longer than a metal obstacle is thick, the fact that the electric field is excluded from the interior of the metal won’t matter much. Even if the metal wasn’t there, the electric field strength wouldn’t vary much over that distance, and on the other side of the metal the induced charges will restore the roughly “correct” field. Since the magnetic component won’t vary much over that distance either, the fact that there’s no varying electric field inside the conductor to reinforce the magnetic field won’t significantly attenuate it.
If you’re familiar with Faraday cages, this will sound all wrong. Isn’t it long wavelengths they can block, and short wavelengths they can’t? This true when dealing with EM radiation in the “normal” radio bands and higher, but it turns out their ability to attenuate radiation falls off in the other direction too (once wavelengths get extremely long). When dealing with EM properties of materials, there are a huge number of different effects that apply in different circumstances, and it’s easy to forget one and confuse yourself.
I went into a slight hunt for more knowledge after reading this, and long story short you need to search NFMI (near field magnetic induction)[1]. As far as I can see from my limited reading the main use case of the tech is nfc (near field comm) and true wireless earbuds.
https://en.wikipedia.org/wiki/Near-field_magnetic_induction_...
Thanks, this will be an interesting read.
Why can't the manufacturers market "smart guns" outside the US? Surely, the NRA's grip isn't world-spanning.
The US is the largest market for firearms, so the NRA can use the threat of boycotting a manufacturer within the states to prevent the technology gaining traction elsewhere.
Aren't there manufacturers that only really target local markets that could profit from this technology, e.g. in China, ex-USSR or South America?
To profit, they would first have to sell the goods. Who is actually in the market for a smart gun? Consumers aren't, surely. There is virtually no upside to your gun tracking you, at your own expense of buying a more complex piece of tech to boot. So that leaves something like (apparently) New Jersey where the government would compel purchases of smart guns because they were interested in the tracking. But eg. China simply don't allow citizens to purchase guns period. There may be some application to applying it to state-owned firearms to track military and police usage, but deploying that at Chinese scale would be an extremely expensive endeavour for what appears to be a solution in search of a problem. Not to mention the biometric lock concept, if implemented, is introducing an entire new axis of unreliability to a life-or-death tool.
Gun owners in the US probably wouldn't want their gun to be used against them in a home invasion, or by their child at a school. Seems like that could be a large-ish market. Especially if you can lobby regulators in favor of making it a requirement for all or some people.
You are right that gun owners wouldn't want those things, but they are unlikely to want a smart gun as a solution to those things.
They want the gun to be available to them, and not be under duress to use a fingerprint reader or pin pad or RFID ring to do it.
Responsible gun owners keep guns out of children's hands by locking them up or supervising them, and irresponsible ones aren't going to want to pay extra for smart features.
I think there's a very narrow range of smart features, something like a gun that is unlocked when removed from a holster, but locks up if it is dropped or grabbed, that might be interesting. That makes having the gun taken from an officer less of a threat, which might have an institutional appeal. Give it a 10-hour maintenance mode so that it can be used as a "nightstand gun" while automatically being locked if left idle for longer, and it would basically meet the needs of police both on and off-duty.
In my personal experience gun owners want mechanical foolproofness too. They want something that's not going to lock up or fail or discharge at the wrong time. Smart features just add a layer of complexity with fail possibilities to address a problem that many of them would prefer to be addressed differently anyway.
I think a country like Australia could be a good starting point for smart guns. Yes, not a very big market-around 8% of US population, with significantly lower rates of gun ownership-but culturally more open to gun control, with a much weaker gun rights lobby, and a marked political tendency towards surveillance and “nanny state” regulation
IIRC Australia doesn't have legal frameworks for gun ownership for the purpose of self defense, and there's no great implementation of smart guns in the first place.
A smart gun is like an AWS authenticated motor twisting ballpoint pen. Just no one ever seriously pays for such a thing, and it has not even been seriously made if it ever was actually conceived. Making it a requirement is basically out of question.
> Making it a requirement is basically out of question
Why? If there’s the political will, it is doable. There are Australian gun manufacturers (e.g. Lithgow Arms, owned by Thales)-and if none of them are willing to cooperate, the government can always start their own gun manufacturer. Indeed, Lithgow Arms was founded in 1912 as a government-owned arms manufacturer, and remained in public hands until the Australian federal government sold it to Thales in 2006.
Same reasons as why things like Clipper Chips isn't happening. It completely lacks technical basis, and even political consensus gets sketchy quick.
Post-war Commonwealth nations are generally bad at gun designs as well - UK tried once and produced an infantry rifle that will(not could) seriously injure its user if held and fired in left hand. So even if forced, the approved gun will be more of a theoretical product, and the smart gun mandate will just be a less politically viable alternative to total firearms ban.
I could not locate credible evidence of a major firearm manufacturer that completely refrains from selling into the U.S. civilian market. (ChatGPT)
Glock, Koch, Taurus, even Czech Zbrojovka all sell to US.
Kalashnikov can’t atm, but also probably doesn’t share the safety concern.
The tech just isn't there; hand-held guns don't benefit from a computerized firing system at all. So any smart feature on human sized guns and less will be totally removable addons, and that completely defeats its purpose.
Many tanks and planes do have smart guns. Electronic firing control with additional software features that impede firing are beneficial and totally fine at that scale.
Seems it's coming though. https://en.wikipedia.org/wiki/SMASH_Handheld
That's just a scope. Comes right off and the gun reverts to a regular M4.
Most(though not all) other smart gun attempts work in a similar fashion; the host gun works exactly as it were, except an extraneous metal bit inhibits firing. If the bit was removed or held down, it reverts to the original host gun and fires normally. As such, the extra bit is literally extraneous, irrelevant to the gun's working.
There are barely any civilian gun markets outside the US. US is really really unique in their relationship to guns.
This. There’s many countries that allow civilians firearms (e.g. Canada and much of Europe), but generally for hunting purposes and thus more likely to be rifles and shotguns than concealable handguns.
Because it’s just a bad idea.
Most of the world doesn’t need that whole setup because:
- Our cultural baseline around firearms is completely different. Countries like Denmark, Sweden, Finland, Switzerland, Austria, and the Czech Republic have plenty of guns at home - and historically, a lot of them were actual assault rifles, not “looks-spicy” semiautos.
- We treat guns like weapons. They live in safes, not nightstands, and kids get taught safety early, the same way you’d teach them not to put a fork in a power supply.
The Swiss do have a lot of guns at home. However, you cannot carry (or even transport guns that are not discharged). Just take them at a shooting range - a popular pastime for Swiss people.
> Countries like Denmark, Sweden, Finland, Switzerland, Austria, and the Czech Republic have plenty of guns at home
None of those countries are anywhere near US levels of gun ownership. See the table here: https://en.wikipedia.org/wiki/Estimated_number_of_civilian_g...
USA has 120 guns pr 100 citizens. Of the countries on your list, Finland is next with 32. Denmark has 10.
> and historically, a lot of them were actual assault rifles
Fully automatic weapons are not legal for civilians in Denmark at least.
Many semiautos are also banned. Semiauto shotguns must be restricted to hold only two shells and you need a special license even for that.
I don’t disagree with your general point, but you’re not making a good comparison IMO.
> Fully automatic weapons are not legal for civilians in Denmark at least.
Same in Finland.
I see at least two problems with smart guns though:
1. Temper resistance is not temper impossibility 2. If a tag allows tracking, bad actors might track good actors?
I would imagine that any manufacturer being seen doing so, would face US consumer boycotts.
The correct answer is - all the designs so far aren’t great.
The military would love a smart gun to cut down on accidental discharges. Cops would love it to stop weapons being used against cops.
The issue is that it has to have a very high reliability (you don’t want it to fail to fire while a suspect is shooting at you). And not much point if it only works “sometimes” with unauthorized users.
smart guns is future dystopian
regular guns is current dystopian
so knife is past dystopian????
Rock was the original topia
https://youtu.be/T7jH-5YQLcE
Regular guns in the hands of the people is the opposite of dystopian.
I like the Univers-like font on this page.
i'm a little bit sad the kernel diagram background is gone
Any idea where the name came from?
Google says
> RuBee is an acronym for "Radio U.S. Bureau of Engraving and Printing",
Weirdly not related at all to Zigbee's naming origins, in spite of their technological similarity.
RuBep? As ever, the fastest way to get a correct answer on the internet is to post an incorrect one:
> The Institute of Electrical & Electronics Engineers Inc., the international governing group for such technology, has designated P1901.1 as the technical designation given to the RuBee technology, which was named RuBee by Visible Assets. "There is no real reason we named it RuBee," said Mr. Stevens. "It actually was named after the song 'Ruby Tuesday.' It just sounded good."
https://theproducenews.com/print/pdf/node/1355 (PDF)
I'd assume "ZigBee" was also an inspiration.
Are there any places where a hobbyist could purchase a tag or reader?
Seems doubtful as this guy has spent a lot of time wigg the this and can’t get one.
.kk