[HN Gopher] Hacking a $200 Under Desk Exercise Bike ___________________________________________________________________ Hacking a $200 Under Desk Exercise Bike Author : wvenable Score : 154 points Date : 2021-04-09 05:56 UTC (17 hours ago) (HTM) web link (codaris.github.io) (TXT) w3m dump (codaris.github.io) | snarfy wrote: | I have one. I don't like to use it. When I exercise my brain is | way off in alpha wave territory. I found it harmful to actually | getting work done. I go jogging or ride a bike instead. | karmakaze wrote: | I came to say something similar, but without the reasoning. I | found that when I used a standing desk over a treadmill, the | mechanics were alright as I type code (rather than mouse | designs). The problem was in the thinking. The level of | exercise increased bloodflow but didn't sync with the careful | deep thought needed for working through complex/detailled | situations. | shubik22 wrote: | Great article. One thing I'm curious about is the process for | interpreting what the raw bytes in each packet mean. Is this just | kind a trial and error thing? Are there different serialization | formats you should look for? Thanks! | wvenable wrote: | Trial and error. You start with the assumption that the | developers are working logically and that they will have chosen | the simplest solution. | | A few of my initial assumptions turned out to be wrong. For | example, since I did see some word (16bit) values I assumed all | the values would be words. That's probably what I would have | done. But that turned out to be incorrect once I started | looking at the values (it's a mix of bytes and words). | shubik22 wrote: | Interesting, thanks for the reply! | bluGill wrote: | Mostly it is a matter of making one change to the inputs you | control at a time and then seeing what changes. Trial and | error, but there typically isn't a lot of error as you quickly | see what inputs cause what changes and learn to ignore the | other fields. Though if the protocol uses encryption you are | probably screwed. | | If I wanted to figure out the fields he doesn't understand I'd | rig up some sort of stepper motor/servo to the pedals so I can | precisely control the input, and then start changing things. Go | from 0 - 120 rpm in .5 rpm increments, with a change every 15 | seconds. Then go from 0 - 60 (or 90) rpm, but over many | different accelerations. | | I used to work for a company that made automotive scan tools | and we did this all the time with the automakers official scan | tools. Even though the auto makers gave us a lot of | documentation, what they did and what the docs say they do is | different. (We even had a full time employee who worked at GM's | offices with access to GM's source code and rights to pass on | the algorithms used: and we still found it valuable to do the | above to GM scan tools to work out what they really did) | shubik22 wrote: | Got it, changing the inputs is a really clever idea. Thanks | for the explanation! | PostThisTooFast wrote: | Interesting that he started his investigation with an Android | app, since Bluetooth on Android is known to be shit. I mean... | it's shit everywhere, but especially on Android. | jacquesm wrote: | This was my take on a connected exercise bike: | | https://jacquesmattheij.com/trainification/ | cosmodisk wrote: | Is it just me or the world gone a bit over the top trying to | squeeze in a million things into any given second of our time? | This Under Desk Exercise Bike is like a wearable chair to me: | | https://www.youtube.com/watch?app=desktop&v=Q1uCYK6wnjk | yabudemada wrote: | Clever idea and implementation! I think from a health standpoint, | though, this is a false positive and it is probably better to go | for an old fashioned _walk_; or to drop to the floor and do some | yoga. | | For instance, sitting down too much is in itself detrimental to | ones health (whether pedaling or not). E.g. prostate health, | posture, etc. | | In contrast, a stationary bike or road bike, the rider can stand | up and pedal fast, etc. There's a much broader range of motion | which make the activity healthy! | amelius wrote: | > it is probably better to go for an old fashioned _walk_ | | For cardiofitness you need to get your heartrate over a certain | threshold. A walk won't do that. | dundarious wrote: | For longevity, AFAIK you don't need that degree of | cardiofitness, and walking is sufficient. It's possible to | reduce longevity through running too fast, for example. | Cultures that have noted longevity are not known for having | an exercise culture either, rather they are moderately active | throughout/several times a day. | | Unfortunately I can't find my sources right now, so take that | as just something some guy said on the Internet. | randcraw wrote: | Two guys. I've seen a lot of confirmation from medical | researchers that moderate rate walking (easy to converse | meanwhile) does provide some aerobic benefit as well as | improve strength and balance. Faster walking (difficult to | converse) delivers more aerobic benefit still, to the | extent that for folks over 55, it's suggested that fast | walking _is_ sufficient to get aerobic benefits. | | And if that's not enough, you can always speedwalk. | novok wrote: | Walking up hills is the gentle-to-the-body challenge | increaser, and makes sense since even tribesmen of 50k | years ago needed to walk up hills and mountains | regularly. | ska wrote: | >A walk won't do that. | | It can if you choose it, for reasonable levels of cardio. | | If you are only going to do one thing (not advocating that!) | you aren't going to be able to beat walking, especially on | varying terrain. | impendia wrote: | I bought an under-desk bike near the beginning of lockdown and | have run the odometer into the four figures. I highly recommend | it to anyone. | | I definitely agree with you that it is no replacement for | walking, yoga, or other active forms of exercise. But I have | found it a great substitute for just _sitting_ while using a | computer. | yabudemada wrote: | What about men's testicular/prostate health though? Bike | seats are specially designed for cycling ergonomics; desk | chairs are design for sitting upright in an ergonomic | _stationary_ position. | | I say this because I had some prostate bruising (I recovered | from that quickly doing yoga), but I attribute it to sitting | too long; I don't even want to think what a pedaling motion | in my chair would do down there! Granted, I have never | pedaled in my chair so I accept that maybe it is fine--I'm | just not willing to take the risk. | | Personally, I'd go more for a walking desk or something where | the motion is natural, but the desired cardio effect is the | same. | impendia wrote: | I haven't experienced, nor done anything to avoid, any sort | of pain or injury like this. Maybe I'm just lucky? | chaibiker wrote: | Regular movement is key, and even switching between sit and stand | every 30m is not enough. We are working on something along these | lines by supporting more frequent useful movement, every 1-2m, | without impacting typing with a smart robotic chair. Looking for | early beta users in Silicon Valley and Boston for May- | https://movably.typeform.com/to/y5NPOA2U | joethescout wrote: | Consistent movement without being distracted that saves me from | back pain? Count me it! Already filled out the form! | donretag wrote: | Years (er, decades) ago, while in college, I was tasked with | hooking up a primitive stationary bike with a virtual reality | headset. The CRT monitor no longer worked for some reason, but | the bicycle itself was still sending out signals, similar to the | original story. | | The university was big into VR and graphics, and had developed a | VR SDK and headgear. Hooking them up was a fun task since I got | to work with C internals, connecting things at a lower level. It | actually worked quite well. | | Today I work on systems that deal with large queries per second, | but almost not as fun as getting your hands dirty with low-level | bytes. | josefresco wrote: | Is it practical to do _fine_ mouse work while pedaling? Or is | pedaling more something you do while checking email etc.? I know | if someone so much as jiggles my desk I immediately notice. | smithza wrote: | Throw the mouse out and just use emacs! | gumby wrote: | As a bonus you get more fine hand exercise -- on both hands! | TeMPOraL wrote: | Be sure to remap Caps Lock to work as CTRL, or else you may | overtrain your left pinkie. | throwkeep wrote: | Tempting. For those who have never used emacs or vim, how | long would it take to get up to speed? | smithza wrote: | If you are seriously interested (which I highly recommend) | _just throw yourself into it_. In the case of emacs, effort | put in is directly correlated to efficiency gained. I was | proficient in basic text /code editing in a few hours and | incrementally tried to shoehorn most editing/scripting | problems to be solved with emacs. There is an emacs | wiki[0], the tutorial built into emacs[1], and a stack | exchange network (mostly for questions related to emacs | lisp which you will want to tinker in pretty soon after | using the tool) [2]. | | Just a note, emacs could be a full desktop experience, | supporting reading/writing email, web browsing, document | browsing (pdfs, html, etc.), picture viewing, text editing, | automation guru, etc etc etc. Some caution against some of | these features but I use it mainly for text editing and | automation support. It has a very robust keyboard-macro- | recording tool, for example. | | [0] https://www.emacswiki.org/ [1] | https://www.emacswiki.org/emacs/EmacsTutorial [2] | https://emacs.stackexchange.com/ | | Additional reading | | [3] | https://www.gnu.org/software/emacs/refcards/pdf/refcard.pdf | [4] https://www.gnu.org/software/emacs | karatinversion wrote: | I've found the emacs manual to be superior to the emacs | wiki pretty much always (three months into my emacs | journey here), fwiw. | chevill wrote: | If you tried to continuously pedal probably not. However, I'm | not familiar with this particular product but every exercise | bike I've used you can just instantly stop for a second or two | and then start back up. So if you intermittently needed to | precisely click on things it would probably be fine. I'm not | sure what type of work depends on continuous, precise mouse use | other than maybe graphics or professional gaming. I'm sure | there's others that I just haven't considered. | Someone1234 wrote: | No, but many people spend a great deal of time reading, and it | is possible to do that while cycling. | rzzzt wrote: | Vertical scrolling could be bound to the direction of | pedaling as well. | wvenable wrote: | I was quite surprised to find that I could code and type | normally while pedaling. I did expect this to be for just | checking email, etc. | | I don't think that you want to do fine mouse work at the same | time as any physical activity. | smithza wrote: | Lastly, I very much did not want all my workout data locked away | in this app. | | This is a great example to demonstrate the simplicity of modern | "smart" products. I think of the Tim Berners-Lee next generation | web product that never got off the runway: just of common and | understandable interfaces for gleaning data from interconnected | devices. The workout domain is a great candidate for | standardizing data-types to pull health-related information into | anyone's standard conforming health database. It should not | require reverse-engineering like this to do. | nradov wrote: | The workout domain has already standardized on the FIT file | format. Pretty much all fitness trackers and bike computers use | it for recording activities. It isn't fully open but anyone can | license the SDK. | | https://www.thisisant.com/developer | | There is free open source software like GoldenCheetah which can | read those comes so you don't have to depend on proprietary | online services. | | https://www.goldencheetah.org/ | marshmallow_12 wrote: | the obvious problem is that exactly no one in the industry has | ever devoted more that 3 brain cells and 5 seconds working out | a universal standard to present their data. Stuff competitors! | And why shouldn't they? They have minus zero interest in making | life easier for their broader (and probably narrower also) | consumer base. | FpUser wrote: | Actually there is ANT+ with profiles for everything under the | sun and BLE with some profiles as well. | TeMPOraL wrote: | Nothing will change until interoperability and full end-user | access to data become legally mandated. As it is, everyone | has every incentive to prevent users from accessing the data, | because the whole business model of IoT is about holding data | hostage to extract ransom from the customer. | Shmebulock wrote: | If users care about that, they'll go to a vendor that gives | them access to the data. No need to legally mandate | anything. | piva00 wrote: | Sometimes users are dumb, sometimes users are | manipulated. Data privacy is a discussion that's been | slowly growing and now has been picked up by the general | public in some places. | | There are some public policies that need incentives to go | against the market, because market forces are not | inherently good. | | Sometimes there is a need to legally mandate something, | or are you also against environmental protection laws? By | this logic, f people really care about the environment, | would it solve itself then? | TeMPOraL wrote: | No, they won't, because of many reasons - it's a well- | known market failure mode. | | Importantly, to pick just one of the reasons, you can't | expect users to accurately judge complex technological | product, especially when facing marketers who will lie to | them. When you're shopping for food or medicine, you're | not expected to understand biochemistry or technicalities | of randomized control trials - you expect the things you | buy to not poison you. Plenty of vendors would be happy | to sell you literal poison - and they did, in the past - | but we've regulated that possibility away. Similarly, for | technology, some of the abuses need to be regulated away, | because you can't expect regular people to avoid the | traps, and the vendors to not be abusive without external | pressure. | wvenable wrote: | There are _no_ vendors that do it; it 's in their best | interest to keep data locked down. You can't vote with | your wallet when your candidate isn't running. | Y_Y wrote: | Isn't my workout data covered under GDPR? Not that I'd | bother trying to enforce it against the likes of Huawei. | TeMPOraL wrote: | That depends. It probably is, to some extent, but you | either consented to this or it qualifies as essential to | deliver the service. I suspect you could get it from the | vendor by sending them a strongly worded letter, but a | DSAR (data subject access request) isn't exactly an API | call. GDPR cares about how your data is being collected | and processed, not about interoperability. We need | separate regulation to force service interoperability and | a separation between hardware and services, so that they | can be interchangeable. | novok wrote: | I've tried desk treadmills with a standing desk, bike desks which | are designed for a laptop and under desk pedalers like this. I | end up ditching them all in the end because the movement is | distracting enough to not let me get into the zone. Whenever I | need to focus on something I instinctually stop moving to 'free | up' brain power to execute whatever I'm doing better, be it a | computer game, writing or coding. | | Also you get more total workout by just going outside on a 30m | walk, not to mention all the benefits of sunlight. Now I just do | walks and explicit exercising vs. the fence sitting that is a | treadmill walking desk. | terry_y_comb wrote: | "Free up" brain power: I turn off the radio when I need to | focus driving on the road (e.g. traffic, rain, snow) | | It sounds absurds. But I think some may do the same. | Darmody wrote: | It is not absurd. There's a reason why people lower the | volume to park their car. | pacman83 wrote: | My experience was the same. I ended up standing on a balance | board at my stand-up desk. This strengthened my core and helped | me to be more alert without actively distracting me. | | And yes, this should be a supplement and not a substitute for | outdoor activity, normal cardio and strength training, | stretching, etc. | StavrosK wrote: | A 30 meter walk doesn't even get me to the door! | novok wrote: | 30 minutes ;) | fataliss wrote: | Humble brag. In NYC it gets you around the block twice! | Grazester wrote: | What tiny block in NYC do you live? | udhdhxnxn wrote: | My employer won't let me get an under the desk bike. I was also | scolded for doing pushups in my cube. Working out from home with | tape on the webcam is great. | FearlessNebula wrote: | Wow, I would fire that employer | secondcoming wrote: | Are they noisy? | RankingMember wrote: | Damn, that's grounds to terminate that employer in my opinion. | Jtsummers wrote: | Seriously? Do they think that if you're not sitting and typing | you're not working or something? Do they measure how long and | often you take restroom breaks? | throwkeep wrote: | Scolded? What was their reasoning? | lfowles wrote: | Great writeup! I did something similar for the (much dumber) | DeskCycle which has a simple odometer. Conveniently I was just | able to plug it into Aux In and track pulses. | | https://github.com/lfowles/deskcycle | slantyyz wrote: | Nice Work! | | I have a MagneTrainer, which is made by the same manufacturer | as the DeskCycle, and uses the same "trip computer" as the | DeskCycle. | | When I bought the Magnetrainer years ago, they had some Windows | games they could link to using the Aux connection, but the | connection kit was overpriced, and the games that were | available looked "meh". | milkey_mouse wrote: | Ah, that Segoe UI WPF app takes me back. I made so many little | utility apps like that when I first got Visual Studio. | WPF/WinForms is what I made my first GUI apps with, and first | discovered why one shouldn't do blocking computations on the main | thread... | vosper wrote: | I think cycling is the wrong motion for an under-desk exercise | machine. I think it should be a very short vertical motion, just | feet moving up-and-down, something you can do without disrupting | your chair posture, or making the rest of your body move too | much. | | Potentially you don't even lift your toes up, just raise and | lower your heels with some kind of resistance. | | Maybe you wouldn't get much exercise this way, but I think | getting a whole lot of exercise whilst trying to work at a | computer just isn't really doable. | slightwinder wrote: | You mean a stepper? | | https://www.amazon.com/-/us/dp/B07NRCZHYJ/ | whoisburbansky wrote: | Scanned the article to try and find this, but did anybody else | notice the name/an Amazon link to the bike in question? | Someone1234 wrote: | I, too, was confused that this was missing, since it seems like | a lot of the Bluetooth data will be brand specific, and they | don't mention even the brand (let alone exact model). | NicoJuicy wrote: | Didn't see it, but an issue could be created on the github | page | wvenable wrote: | The brand is Exerpeutic and the model is 7149 but it seems that | model number is country specific (Canada). | whoisburbansky wrote: | Ah, thank you! | fiftyacorn wrote: | If your doing this sort of project your can get a head start | integrating into golden cheetahs dashboard. I done it years ago | with a Google map/turbo trainer as a project | Grustaf wrote: | > "my desk is actually the perfect height for peddling" | | Why is it so hard even for native speakers to spell the verb | "pedal"? I mean it's spelled exactly like the noun, which most | people seem to be able to spell properly. | | It's a genuine question, I see this all the time, maybe most of | the time actually. It's strange because typically people tend to | over-generalise, not the other way around. | RankingMember wrote: | Probably the same part of the brain fouling up that causes the | loose/lose screwup we've all probably made. | hoophoop wrote: | As a non-native speaker I might make other grammatical errors | but not the ones related to phonetics. | | Often I found more difficult to understand English written by | native speakers than by others because of that. | gumby wrote: | "Peddle" is a legitimate homophone for "pedal". Some people | hear the words while they read/write so make this class of | mistake. Such errors always confuse me momentarily as I don't | hear the words, but it doesn't make me think there's something | wrong with the author. | | They can also come from autocorrect guessing, though probably | not this case. | | (FWIW Reading poetry doesn't work for me and I have long | assumed it is only a pleasure for people who hear the sound | while reading). | iso1631 wrote: | > FWIW Reading poetry doesn't work for me | | How about Oxford poetry? Or Maidenhead? | gumby wrote: | I just don't hear sound when I read (in any language) so | tools the poet uses such as meter, assonance etc are lost | on me. Of course I can carefully read for sound but then | I'm so busy doing that that I lose the thread of meaning. | | I can listen to poetry and musical lyrics, and there | cadence and phonemic clues help with memory and recognition | and can even be playful or fun (as intended!). I've never | grokked how one could read that way though clearly many, | and perhaps most, people do! | Grustaf wrote: | Read aloud! That's how poetry is supposed to be read. | Hnaomyiph wrote: | I'd imagine it's from lack of use in daily writing, combined | with a lack of a ubiquitous context-aware spell checker. I make | similar mistakes quite often | Grustaf wrote: | It's not just the seldom used gerund. People even write | "peddle" for the present form. | armagon wrote: | I wish I could use a (Mac) desktop application to talk to my | Fitbit. It looks like there was one years ago. | | (First and foremost, I'm at my computer all day long. If it has | trouble syncing, I'm right there and not going anywhere. I hate | having to find my phone and try to get the data synced just to | see how well fitbit thinks I slept last night. Also, would be | nice to access my data from my device without involving the | cloud.) | RHSeeger wrote: | My wife bought me a new fitbit for Christmas (mine is getting | old, frequently just loses it's charge, etc). It would not | allow me to initialize it without syncing to my phone, which | had to be running their app. I wound up returning it because I | don't _want_ to run their app on my phone. | | I even looked into if it might be possible to work around the | issue. Turns out, the fitbit, which is advertised as having a | GPS, actually uses your phone's GPS. It has one of it's own, | but it's apparently absolute garbage; it's inaccurate and it | drains the battery extremely fast. | | I'm still using my barely functionalit fitbit charge 2. | bluGill wrote: | Pine64 is working on a smart watch. If you are a developer it | might be worth hacking on. | | Just pointing this out for those in the same boat as you. | Personally I hate things on my wrist and so I don't know if | it is any good as I won't be using it anyway. | judge2020 wrote: | Unfortunately that's the price you pay to use most devices - | they need accompanying proprietary software. There doesn't | seem to be a big enough market for open-standard or open- | protocol health/fitness tracking. | RHSeeger wrote: | But... it doesn't. I can look down at my old, not-phone- | connected fitbit any time I want and see how many steps | I've walked so far during the day. Or what my heart rate | it. Or any number of other things. | | It doesn't _need_ the phone to be able to do that part of | it's job. And I don't want the "challenge your friends to a | walk-a-thon" junk that does use the app. | nradov wrote: | There is a semi-open standard and protocol for fitness | tracking: the FIT file format and ANT+ for wireless | networking. However most devices which support those | standards like Garmin generally require the use of a | proprietary mobile app for initial setup. Once you finish | that you can uninstall the app. | vagrantJin wrote: | For some reason, I'm suddenly intrigued by the notion of building | a device to exercise with while sitting. | Sohcahtoa82 wrote: | I interpreted the title to mean they exploited the bike and got | code execution, similar to the guy who got code execution on a | smart butt plug and presented at DEFCON 27 [0]. | | [0] (Slightly NSFW) https://youtu.be/RnxcPeemHSc | jrm4 wrote: | Unless there's some sort of "resistance" thing; isn't something | like this "hack in a weekend" easy with any stationary bike + Pi | + camera or something? Just point it at the feet and record | cycles? | moioci wrote: | picture looks like "Exerpeutic 900E Bluetooth Under Desk All User | Height" | wvenable wrote: | That's close but that model has an elliptical pedal design. It | wouldn't surprise me though if the Bluetooth connectivity was | identical. ___________________________________________________________________ (page generated 2021-04-09 23:00 UTC)