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Very few Android phones have a pressure sensor.
by LukaszWiktor 2y ago
Very few Android phones have a pressure sensor.
- adastra22 2y agoI’m pretty sure every Android phone does. It’s called a microphone. It doesn’t give absolute pressure values, but that is not needed for this use case.
- rossant 2y agoMaybe premium Android smartphones do? My Galaxy S24+ seems to have one. Edit: at least the excellent Physics Toolbox Sensor Suite gives me a barometer signal indicating 102570 Pa right now.
- sliken 2y agoI was pleasantly surprised to note my pixel 9 has a barometer, 81,500 or so right now, I'm at 6,000 feet of elevation.
- LukaszWiktor 2y agoTrue. Flagship smartphones, and some rugged models do have a pressure sensor.
- plantain 2y agoVery many do - https://m.gsmarena.com/results.php3?chkBarometer=selected https://m.gsmarena.com/results.php3?chkBarometer=selected
- douglaskayama 2y agoThis GSM Arena search brought a Galaxy S25 Ultra in the results, an unannounced phone.
- LukaszWiktor 2y ago> Your search returned 653 results. When you remove the filter, it returns 12177 results. So only ~5% of phone models include a barometer.
- yccs27 2y agoThat's all phones ever, not current/popular models. When you restrict it to the last 10 years, you get about 12%, and of the 70 most popular models almost a quarter are equipped with a barometer.
- antonkochubey 2y agoHuh? I restricted it to 2023-now, and got 146 results. 80 for 2024 only.
- lolinder 2y agoFor an app as popular as Transit this is a purely academic exercise—25% of the most popular models is way too low to be worth building their detection around, even if they could assume that all of their customers use the most popular models (which they obviously can't).
- stavros 2y ago25% of popular models doesn't mean 25% of phones currently in circulation. If the iPhone has a barometer (which it does), that's already a huge share of phones out there.
- fragmede 2y agoyou wouldn't need all of them to have it, just enough so that wifi beacons in-between train stations could get added to the bssid - gps coordinate map. Though if the vendors wanted work with you, you could just tell them wifi bssid and the gps coordinates of them and the rest of it would just work.
- Normal_gaussian 2y agoThere are unlikely to be wifi basestations detectable in between stations, because these are underground trains.
- fragmede 2y agounless installed by the system operator, which is why they'd know the gps coordinates for them I'd have to have missed the title of the post, not read the post itself, not read GP's comment, not thought about why there'd be a pressure change, to have missed that particular detail. I appreciate you trying to be helpful though. :)
- _kb 2y agoYou don’t need fixed base stations. Just infra on the train that rolls bassid based on location data the train already has. This would silently hook into native location services already on devices without additional sensing or models trained on other sensor data.
- ssl-3 2y agoThat's... actually pretty brilliant. I wonder if it'll Just Work [eventually, given enough repetitions], or if the crowd-sourced network location algorithms will filter it because it is dynamic.
- bluGill 2y agoThere should be - everyone on the train wants connectivity. Even if there is wifi on the train, that wifi needs something to connect to.
- oniony 2y agoI believe many do because it's used to fix GPS data when at different elevations, if I remember correctly. https://nextnav.com/why-phones-have-barometers/ https://nextnav.com/why-phones-have-barometers/
- telgareith 2y agoMaybe it'll help achieve a lock faster- but theres nothing else needed for GPS besides GPS. The military really doesn't like dependencies.
- traverseda 2y agoNot a faster lock, air pressure is actually more accurate on the z axis for the most part. GPS is not great at height, and including an extremely accurate barometer is a big help.
- umeshunni 2y agoWhy is GPS not great at height? If you know your location is x,y and you have an elevation map, you can map x,y to an altitude z, right?
- sgarman 2y agohttps://ciechanow.ski/gps/ https://ciechanow.ski/gps/
- sliken 2y agoSure, assuming you are not in a building, balloon, helicopter, plane, drone, etc. Not to mention interesting topology like a cliff where an error in long/last of even a single foot could mean your altitude would vary by 1000 feet.
- Wowfunhappy 2y agoI know nothing about this, but I imagine two people at the same latitude and longitude could be at different altitudes. A trivial example would be people on different floors of a skyscraper—although I suppose gps works poorly indoors anyway. Still, even outdoors there are peaks and crevices, and on a steep slope a very trivial change in lat/lon could lead to a major change in altitude.
- maven29 2y agoJust like the heart rate monitor, this was also moved into smartwatches for optimizing revenue from those who truly need it.
- resoluteteeth 2y agoAre you saying that smartphones used to have heart rate monitors but they were removed to force people to buy smart watches?
- astrange 2y agoAny phone that can record 120fps video has a heart rate monitor, if you can calibrate it.
- connicpu 2y agoI forget which generation it was now, but many years ago I had a Samsung Galaxy phone that had a sensor that could measure your heart rate if you put your finger over it
- superhuzza 2y agoThe Galaxy S7 definitely had this feature. The problem is, it was basically useless. The main use case for heart rate monitoring is continuously throughout the day/night, or during exercise. A watch is very good at this. An optical sensor on the back of your phone is not. Periodically checking your heart rate by holding your phone in a specific way is not a useful feature for that many people.
- 6510 2y agoFor me, just having something that you can check 1 time per year is much better than nothing. The anecdote: I was working two heavy manual labor jobs 7 days per week and felt absolutely fantastic, glowing with power. Turned out the heart rate at rest was 180 lmao. Like a rabbit. Took a few days off, it dropped below 70.