There's an ARM Cortex-M4 with Bluetooth inside a Covid test kit

[new299]

The Lucira test is in my opinion a bit more interesting:

https://aseq.substack.com/p/inside-the-lucira-check-it-covid

They include an STM32, but the instrument is performing an Isothermal PCR molecular test which makes the inclusion of a microcontroller a requirement.

Obviously throwing out electronics like this seems quite wasteful. But overall our society is fairly wasteful when it comes to disposable electronics.

[Rebelgecko]

The Cue testing devices are interesting. The Bluetooth, battery, and most of the interesting bits are all in a reusable device with a slot for single-use cartridges. The cartridges are fairly dumb (other than the chemical stuff I think there's just an i2c chip)

[amelius]

> They include an STM32

This might explain partly why they are all sold out :(

[bloopernova]

Wow, that is wonderfully complex!

I do wish that there was an established recycling pipeline available for them though.

[AlexanderDhoore]

As a European: why are there chips in this? I just broke open mine and it looks like this: https://imgur.com/a/muz7FIy

I bought 50 of these 2 weeks ago. Were 3-4 euro a piece.

[jffry]

For reference, this is one specific type of test available in the US, there are other more common tests which are electronics-free.

There are some valid reasons for tests like this to exist. To quote later on in the linked Tweet thread [1]:

  BTW it's easy to say this is wasteful, and it probably is, but just like with the pregnancy test, you should consider that there's three main problems that can affect the accuracy of lateral flow tests like this:
  1. inconsistent lighting
  2. incorrect timing
  3. human error
  
  having a 2$ computer chip and 50 cents worth of plastic  & lenses removes all those sources of error. 
  And making it bluetooth removes a source of e-waste! it means it doesn't need to have a screen, it can just talk to your phone.
  
  for example, consider that a bit more than 1 in 12 people have some kind of colorblindness.
  Having a computer say "POSITIVE" or "NEGATIVE" is going to be easier to see then the uncertainty of "is that stripe red? can I just not see it?"

[1] https://twitter.com/Foone/status/1475254812816019456

[pydry]

Personal data collection, probably. I cant imagine it is for the user's benefit that it uses bluetooth and requires an app, but it does let them hoover up your contact details and infection status. This probably sells > cost of the electronics.

[ljm]

There's probably a mindset of having to use IoT (or close enough) no matter how inappropriate the use-case is. Like how people try to find reasons to use a blockchain, or rewrite something in Rust, or host a kubernetes cluster.

A low-tech solution would be too boring or easy.

[mrunkel]

It’s for the Bluetooth piece. The optical sensor reads the result and the turns on the light and/or lets the phone know over Bluetooth.

Seems unnecessary, but if people want to buy it…

[Nitrolo]

I'm wondering if they're subsidized, but the price in Germany at the supermarket hovers around 1€ each. I was really surprised to hear that these are not a thing in the US, any idea why?

[thescriptkiddie]

It's to hide the fact that inside, the test is just a piece of chemically treated paper that costs less than 1 EUR to produce. That way people don't get as mad when they have to pay $200 for them.

[rcarmo]

Nope. We just get overcharged.

[BurningFrog]

Most likely because FDA required it.

[exmadscientist]

Nordic is not really that cheap if you just want a Cortex-M4. You buy Nordic parts for their radios.

If you just want processing power, GigaDevices has an M4 at less than $1 last I checked. Unfortunately, it wouldn't work for the design we were working on as the standby power consumption wasn't great.

[AlotOfReading]

If you want bargain basement processors with connectivity, Qualcomm is still selling many of the old CSR chips. The low end chips went for <$0.50 in volume and the power consumption was often barely worth measuring. We used to chuck them into products every time every time I lost an argument with the hardware team about whether 10-15 cents of BOM cost is worth 3 months of painful bringup.

[monocasa]

I don't think they wanted an M4 per se, but instead wanted a bluetooth radio to save on the cost of a screen. The Nordic chip just happens to be based around an M4.

[evan_]

I wonder why they didn’t use NFC. They could get away with a much simpler chip, or even a fully analog solution if they didn’t need the complexity of Bluetooth.

Seems like you could just about accomplish the same thing with a pair of NFC tokens, a photodiode, and some transistors. Basic components. Connect one of the two NFC chips to the coil depending on how much light is reflected off the test strip. When you scanned it with your phone the activated NFC chip would respond with a URL containing a unique ID which could be interpreted by the manufacturer.

[sofixa]

One reason i can think is that NFC wasn't ubiquitous on non-premium phones a few years ago, unlike Bluetooth.

[bushbaba]

iPhones only relatively recently started supporting nfc for non payment use cases. https://blog.nordicsemi.com/getconnected/native-nfc-support-...

[grishka]

Not all phones have NFC, especially cheap Android ones like Xiaomi, but every single one has Bluetooth.

[evan_]

Interesting how half of the replies to this blame Apple and half blame Android

[logbiscuitswave]

Or if they are already using Nordic chips, slightly more expensive nRF52832 can also do NFC.

[tjoff]

Because of apple.

[Uptrenda]

I worked at a company that was using these chips to control doors. They're extremely cheap chips, but writing code for them is not pleasant. Documentation is lacking and the tools people use to write code for it suck. Props to the devs who helped put this together.

[rurban]

I write baremetal fw for those chips. No debugger, extremely bad stdlib which I rewrote, no qemu. Horrible modem interface. But still much more pleasent than Linux FW or raspi's.

They are cheap, last 10 years with a single battery, and do only what they need to do. Also secure. No crazy attack vectors. And easily symbolically verifiable. And I wrote tons of simulators and fuzzers for them.

[bsder]

> Documentation is lacking and the tools people use to write code for it suck.

Okay, I'm going to ask "Compared to whom?"

Nordic has been one of the better BLE chip manufacturers in terms of documentation, in my experience.

Most places use Keil tools directly from ARM. So, if programming these sucks, so does programming most embedded Cortex M4 chips. (No argument. Keil sucks. However, that doesn't mean that Nordic sucks any worse than anybody else).

And now you can program Nordic chips using Visual Studio Code.

[jkelleyrtp]

In contrast, embedded Rust is quite a pleasant experience on the nrf line, including the 52xx series.

[floatboth]

nRF52s are definitely not extremely cheap, they're high-quality fully-documented dev-friendly chips with lots of onboard resources. If you want cheapest BLE, there's some utter crap from Dialog Semiconductor that comes with a proprietary SDK in ROM and one-time programmable (!!) memory for the application (external flash can be used in development).

And you DO NOT have to use the Nordic SDK, there are lots of better and fully FOSS options — Apache Mynewt, libopencm3, Rust nrf-rs…

[wcunning]

Any chance I can reuse one of these boards given that I have a few of these test kits? Or are the tools so bad that it's not worth it?

[netr0ute]

At that point, why not just use something like the original SoC from the Raspberry Pi 1 and use the plethora of Linux dev tools available?

[joezydeco]

Having worked on automated ELISA equipment decades ago, it's kind of interesting to see this come full circle.

The earliest machines used a light source and color filter to try and get the signal from the finished enzyme sandwich. Then lateral-flow came along and it was up to a human to make the observation. Now we're back to the computer doing it again.

[dmix]

US paid $230M to have this device built.

https://www.cnbc.com/video/2021/02/01/us-231m-deal-ellume-at...

[tssva]

They paid $230 million for 8.1 million devices and the building of a US based manufacturing facility capable of producing 19 million devices a month.

[kristopolous]

I can't help but imagine a parking lot full of Ferraris at their offices

Maybe I'm Elizabeth Holmsing it, but I'm thinking it could have been done for 1/50th that price while still paying people well and providing them the resources they need.

Am I missing something?

[wcunning]

So my followup question is: I have a few of these, can I do anything with them once I'm done with the test? Hook up to the headers and reprogram? What about the Binax test? Or any of the other "connected" ones?

[wcunning]

Answering my own question: he gets there much later in the thread -- looks like single wired debug is available at a pad on the board.

https://twitter.com/Foone/status/1475268224635662336

[stbtrax]

probably not worth your time unless you're looking for an art project. you can get a devkit for dollars that has pins brought out and more flash and ram https://www.aliexpress.com/item/1005001593980172.html

[numpad0]

Basically all those nRF5x products are Arduino compatible AirTags with a battery included. IIRC they also have an imprecise but low power, chip integral temperature gauge. Maybe a wireless interval thermometer might be a good start?

[theta_d]

Binax is just some cardboard and a strip, no chips.

[wcunning]

Note: Hackaday discussion available at https://hackaday.com/2021/10/17/electronic-covid-test-tear-d...

[qbasic_forever]

FYI some of those Ellume brand tests were recalled: https://www.fda.gov/medical-devices/medical-device-recalls/e...

[bobsmooth]

The chip is $4. The test is much more expensive than that.

[gst]

The expensive price of the tests is actually a whole different problem. For the last tests that I bought at Walgreens (InteliSwab) I paid around $25 for two tests.

Meanwhile I'm currently in Europe and as a consumer I can buy Antigen tests for around 3 Euro per test (would be less than 2 Euro if bought in bulk). As far as I know those prices are not subsidized.

[55873445216111]

The Digi-Key price is $4. The direct price when buying millions of units will be a fraction of the Digi-Key price.

[aetherspawn]

And it’s about half price @ 1000 units.

[joe1138]

Imagine a Beowulf Cluster of these!

[roeles]

For those interested: I ported FreeRTOS 9 to an nRF52840 in my previous job. This family used a lot. It's in my Tado smart radiator knobs, in the AirTags.

I can only compare it to FreeScale chips, but one thing that pleasantly surprised me is the flexibility in pin-assignment. Instead of the pin-mux that we'd have to do on the MK24, I could just assign pins during usb/i2c init without any limitations. The SDK is quite elaborate, although sometimes a bit difficult to use in C++.

[londons_explore]

An any-to-any IO multiplexer turns out to be pretty large in silicon area. You're paying extra for that feature as opposed to devices where each pin has a choice of just say 3 functions.

For most users, they prefer to have the chips cheaper and spend an extra few minutes of engineer time figuring out which pins need to be hooked up to what.

I can see for smaller volume devices where engineer time dominates, and devices that you want to be really field reconfigurable, the all-to-all mux is worth it though.

[fnord77]

funny there's a chip shortage for certain chips. yet here are disposable chips...

[no_time]

I don't get the worry about it being hackable. Sure, you could engineer the whole thing with crypto in mind from top to bottom. With trustzone on the chip and safetynet on the phons but what's that gonna achieve? The test is not done in a controlled enviroment anyways. People looking to cheat the system could simply get their friends to do their "hackproof" tests.

[daneel_w]

I can't believe even a fractional percentage of customers would find it useful to have wireless interaction with a disposable single-use test kit, compared to reading the result off of a passive testing strip. It would've been reedemable if they had sold the strips as a separate replacable product so that the electronic device could be fully utilized.

[belter]

It might have its uses...If for privacy reasons, the testing subject is in a closed room and you want to make sure they report from the correct test.

[Havoc]

Seems like unnecessary e-waste to me.

[rasz]

~$30 and they werent even good "Ellume Recalls COVID-19 Home Test for Potential False Positive SARS-CoV-2 Test Results" https://www.fda.gov/medical-devices/medical-device-recalls/e...

[ir193]

edit: was wrong about the test price. It should be $38.99 / ea test.

[heavyset_go]

This is cool, and I enjoy foone's tweets about hacking around on embedded electronics you can buy at your local pharmacy. I just hope the unscrupulous don't have a field day with the potential spin this story and headline can have.

[Fnoord]

Also see this previous HN thread:

https://news.ycombinator.com/item?id=29637592 (Faking a Positive Covid Test (f-secure.com))

[hansihe]

I just flew in to Minneapolis from Europe last night and they handed these out for free at the airport. Was really surprised to see the Bluetooth sign on the box.

[theHIDninja]

So this is where all the chips are going during the shortage. Good to know we finally get some answers to that.

[iszomer]

I would have understood an IoT widget for the purpose of contact tracing but for this instead? ...

[thescriptkiddie]

Foone has specifically asked that their tweets not be submitted here.

[abeyer]

So how long before someone starts buying up covid tests to strip these out again and resell to the supply chain challenged?

[paxys]

Buy a $40 test to resell a $2 chip. Genius.

[ekianjo]

The tests are not cheap

[bombcar]

Excellent. Just what the Dr ordered.

[ip26]

This is depressing. Single use disposable. Full of copper, gold, tungsten, halfnium. Will leach poison into the ground. Some of the most advanced technology of our age. Use it once, toss it in the trash.

Meanwhile the paper versions work just fine.

[malwarebytess]

The optics on this seem to indicate that it is just a lateral flow test of some kind.

It's not even different. Instead of having to interpret a couple lines you have software interpret the strip and tell you over bt on your phone. So much tech for so little.

[fanzhang]

Another view is that it's a great illustration of the relative price trends in the last 50 years. Healthcare has gone way up in price, and tech way down. What was a supercomputer 50 years ago is now a small fraction of the cost of a chemical test (which requires FDA approval).

[aeternum]

We've made significant advancements in catalytic converters over the last decade and many waste management centers are able to incinerate much of the trash without the toxic emissions. They can then use magnets and eddy current separators to extract nearly all the metals out of the resulting ash.

[throwaway4good]

In Europe a COVID19 quick test is 1-2 USD. This is 20-40 USD? For a device you only use once.

Why is there any kind of market for this?

[shiftpgdn]

If you read the full Twitter thread they explain that paper doesn’t work for everyone (the color blind and the incompetent, for example.) There is a use case, it just might not be for you.

[distances]

> Will leach poison into the ground.

Electronics must not be disposed with general waste, I'd imagine all Western municipalities have special recycling programs for electrical devices. Not sure if they'd be that happy to receive used covid test kits though.

[Lamad123]

And they are crying about semiconductor shortage, and blah blah...

[sydthrowaway]

Why don’t we have biodegradable chips?

[johannes1234321]

Because we don't tax cheap non-biodegradable things and don't really care about dismissal.

We could subsidize research into biodegradables, though ...

[ctdonath]

.

[sodality2]

wrong thread methinks

[c-smile]

Do we have Doom running on it?

[programmarchy]

Depends if the test comes out positive or negative.

[ekianjo]

as mentioned in the thread it would need more RAM to do so