Teeny-Tiny Bluetooth Transmitter Runs on Less Than 1 Milliwatt | Hacker News Reader

Teeny-Tiny Bluetooth Transmitter Runs on Less Than 1 Milliwatt

spectrum.ieee.org

122 pointsBilters47 comments

If that is practical to use, it would open an entire new field of applications. Constrained devices currently consume roughly 50 times that much during transmission on 802.15.4 or BLE. While there are sensors who are used for 10 years on a coincell, they achive this by spending most of their lifetime in deepsleep at under 1uA with disabled transceivers.

Does anyone remember the amazing backscatter tech by the UW kids (https://www.jeevawireless.com/)? I've been waiting on them for years now. They were supposed to be to market by now with a $0.25 chip that does 2.4GHz at 1/10,000 of the power. They have reliable functional demos doing long range transmission using 59 micro watts. They were also working on a battery free emergency cell phone.

And thus begins a Cambrian explosion of new spy devices that run (practically) forever off a button cell.

The bleed/drain rate of many batteries is far more than 1mw.

FYI this is not terribly new – BLE was already extremely power efficient and could easily run for > 1 year on a watch battery

you're not going to be able to stream audio or video from a device like this, but BLE was not designed for that anyway.

Whats the power consumption like for audio recorders? Because as far as I know video is out of question at these energy levels.

I'd love to see what kind of range we can expect from that haha. Still a great achievement for BLE! I have an iPhone and often find it via saying "Hey Siri", and have sorely wished for a way to locate more "mundane" objects, and if this were to ever cost around the price of an ESP8266 it'd make that possible. (Yes there is tile and similar tags, but those are expensive, and I mean to have a tracker on a bunch of items)

I never understood Tile and the rest.

The only thing I want a locator on is my phone.

You've never misplaced anything but your phone?

Creating more electronic waste for that once in a year time you need to locate your keys VS spending 15 min to find them.

It's nice in theory but it doesn't really solve anything, a bit like Juicero, nike self lacing shoes, &c.

If you start putting bluetooth tags on everything you could potentially forget somewhere you're in for a wild ride.

I use tile to find keys at least once a week.

Im envious of your ability to keep track of your things. I end up needing to use the one of my tiles to find either my keys, phone, wallet or work badge almost every other day.

When the batteries in them go dead its easy enough to to swap them out myself for new ones.

Wow! Forgive me, but why can’t you just keep them in the same place? My wallet and keys are 100% of the time in the same place when I’m at home, and my phone is either in my pocket, my hand, charging in a specific spot, or on a random surface in the house. That last one is rare, but happens. It takes roughly 30 seconds to walk through the house and find it. What am I missing?

Different people are different.

I now keep my personal things in the same place at home >99% of the time, but it's taken me decades of training to get to this point.

For example, I used to walk in with my keys, and would be ready to put them into their home. But there could be an interruption between the time I used the keys to open the front door and when I put them in their home. For me, that situation would often cause me to put my keys in an inappropriate place, which often caused them to get 'lost' later on.

The behaviour modification, for me, was causing me to resist any reaction to any interruption until the necessary things landed where they belonged.

Different people are different.

That sounds more like you just need to have the place that you put your keys immediately by the door.

Personally, I've found having them in the one place works really well until my under-5 year old wants to play "driving to daycare" and forgets where they left them once done.

Also great for parents with children of any size, just place it under the insole of their shoe.

It's not nearly sturdy, weatherproof, slim, or loud enough to work there.

The 30 foot range and assumption that it is still in the location where your phone last connected to it are further limitations...

Its the thing I'm most worried about misplacing.

With the new tile you put it on your keychain, and if you lose your keys the app on your phone can find them. And if you lose your phone, the keychain can find your phone.

I never understood Tile and the rest. The only thing I want a locator on is my phone.

I felt the same way until my wife lost her car key and the dealer wanted $1,200 to replace it.

(It turns out it's not the electronics that are expensive, it's the crazy engraving they use these days.)

> I felt the same way until my wife lost her car key and the dealer wanted $1,200 to replace it.

More info, please. (:

Modern cars are so up their own arse in those kind of things that everything costs an arm and a leg to service or replace. I'm probably sticking to 90s/earlier cars as long as I can.

They've regressed in so many ways - touch screen radios are an abomination, exorbitant key replacements/servicing in general, annoying gas flaps you can only open from inside the car, digital pedals that are usually way over-responsive.

Too many over-engineered points of possible failure - when my mother got her 2008 Nissan a while ago we couldn't figure out how to open the gas flap, turned out a handle had fallen off of a lever hidden somewhere on the floor to the side of the seat. As if gas siphoners don't probably just carry around something to pry the flaps open. And more seriously, wasn't someone recently unable to get out of a burning Tesla because the digital door handle didn't engage? Not to mention remote exploits have been found that theoretically let hackers take control of a car remotely while it's being driven and control the steering/brakes/acceleration/etc. I'll pass on the incrementally better mpg/safety.

An electric conversion of a 1940s led sled is my dream car.

I thought the same, but then I somehow lost a remote in a 600 sq ft home and still haven't been able to find it.

Tile as-is is way too big and expensive for me to consider, but I absolutely understand the appeal of the product category now.

I lose my keys constantly despite making habit changes to put them in the same place. Tile solved this problem for me.

> I never understood Tile and the rest.

People lose things.

people are willing to sacrifice privacy for convenience or they are ignorant of the sacrifice itself.

I like the idea behind Tile, but there've been so many times where the tile I had was sitting within 3 ft of me but my phone couldn't locate or ping it.

I use trackr. 4 out of 5 times I need to find something, the battery is dead.

I would LOVE to have something on my glasses! Even just something to tell me I'm in the same room. My prescription is powerful enough that I need them, generally, but weak enough that I take them off often at home. This also means I lose them a lot and I can never quite seem to remember which room I was in when I removed them. :)

My solution to that was zennioptical.com. I bought about 10 pairs for a total of less than $100 and just leave then all over the place.

At this point, I'd just settle with set top boxes (is that what they're called still? The DirecTV, Dish, etc. digital ones) that had a button to locate the remote.

Probably not much range, I'd be surprised if it's more than a few metres. The intended use case would likely be with some kind of powered repeater or receiver within reasonably close proximity.

That still opens a lot of new opportunities though.

Getting closer to Jim and Pam bluetooth earpiece?

What would be the distance range of such tiny transmitter?

like any transmitter, this depends on the gain of your receiver :)

And the stuff you have to penetrate. I turn the power down to -40dbm on one of our products during "Just works" BLE bonding to help minimize the surface area but I have the luxury of thin plastic enclosures, decent trace antennas, and the ability to force the user to place the devices right next to each other.

Which BLE chip do you use? On the nRF51, it actually remaps -40dBm to -30dBm. With the newer nRF52, you can use NFC for OOB authentication for more security. I'd love to know more what you're working on.

The 52832 in a third party module and as you know that maps -30 to -40. NFC would have been nice but my hardware guy didn't bring the pins out on either side which is a damn shame because I don't have any user inputs other than power on/off on one side of the link. Email is in my profile if you'd like to know more

Isn’t this low enough to use ambient radio waves for power?

"...magnetic monopole..." is mentioned in the photo caption :)

Yeah, I was confused about that as well. What are they talking about?

I'm not an expert, but I presume "magnetic monopole antenna" refers to a monopole antenna[1] with some affiliation with magnetics. I presume the word "magentic" came from this description in the article:

The key part of an oscillator is the resonant tank circuit: an inductor and a capacitor. Energy sloshes back and forth between the inductor’s magnetic field and the capacitor’s electric field at a resonant frequency determined by the capacitance and inductance. In the new circuit, the team used the antenna itself as the inductor in the resonant tank. Because it was acting as an inductor, the antenna radiated using changing magnetic field instead of an electric field...

Though I don't follow the meaning of this paragraph, what with the energy sloshing. I guess it comes down to the antenna being used as an inductor.

[1] https://en.wikipedia.org/wiki/Monopole_antenna

Ah, that could be where the confusion came from.

> I presume the word "magentic" came from this description in the article

A poor choice, then, since magnetic monopoles famously don't exist (or aren't known to exist). But, mistakes happen.

It's "magnetic monopole antenna". A "monopole antenna" is a type of antenna. There are different type of monopole antenna. Two of the types are called "electric monopole antennas" and "magnetic monopole antennas". Here's a paper that looks at those two types [1].

[1] https://pdfs.semanticscholar.org/dd05/23adec09486c283e1ab348...

This is quintessence of a typical discussion on the Internet. Context matters and it's expensive to gather appropriate context. Usually it's not as simple to explain as in this case.

"I don't have to read further because I know for a fact that <this bit> is bullshit". It's a fair heuristic. It's just that it is so difficult to have a deeper meaningful discussion without some trust established first (so that you know you're not wasting your time).

As a ham with an Extra class license I'm understanding that it was a type of antenna and am now regretting this commentary but for just a moment wondered if it was an April fools page published early.

I do have an interest in magnetic antennas (antennas in general) and also appreciate the paper listed by tzs. Thank you tzs!

Sorry for dropping the SNR in here :)

Reply on news.ycombinator.com