If your sample rate is 100 Hz you would usually apply analog lowpass filtering at around 40 Hz, well below Nyquist. But with enough load on the line, since no filter has perfect attenuation in the stop band…
> However on android the sampling rate of the acceleration sensor is limited to 50/s. At least if you install through the official app store.
My understanding is that it’s the same even on iOS (or at least on my iPhone SE 2020). More specifically, the output only measures till 50hz (but the sensor sampling rate is actually 100hz - Nquist, you need double the measured frequency as sampling frequency, yada yada.)
I get 100/s on an iPhone SE2. 50/s on a Samsung Galaxy A16 which was released in 2024 or 2025, but that is due to an API restriction. You can export from phyphox (.xslx or .cvs). You get timestamps in the first column. Phyphox refers to the raw data rate, not Nyquist freq.
The sensors have analog lowpass filters that can be adjusted in order to avoid aliasing.
In general, with more bandwidth you can do more intrusive things. But if you want to tell wether two people ride in the same car, 50 Hz should be sufficient anyways.
By the way, it’s important to note that measuring vibrating things can permanently damage the OIS VCs in the camera. (See: Apple’s warning against motorcycle mounts.) my iPhone already had a broken OIS so I didn’t mind as much.
Huh? I get 500 Hz here on a Samsung from 2019 and make use of it regularly. Sensor frequency is one of the things I check before buying a new phone, surely newer Android versions haven't killed that with new api restrictions?!
Edit: no, it can't have. Then the phone sensor database would show that since it is built from submissions within Phyphox: https://phyphox.org/sensordb/
I'm not sure what problem you're running into (perhaps a very unusual phone that has only a 50 Hz accelerometer) but Android/Phyphox can do way more than 50 Hz
It is a Samsung a16 and it is just an observation I made, not a problem at all. If it was, I would try another installation source or even switch to a degoogled OS first to get more control over the hardware. Only thing I tried to get more samples was fiddling with the App restrictions. But it really doesn’t matter at all.
You need a lot more impulse and more fuel to go twice as far. Probably more correction burns. A longer final burn before entering the atmosphere. So the risk of loosing the engine is much higher and probably increasing more than linear with burn time/change of impulse.
Wouldn’t the soviets or any other adversary prepare against letting NASA capture their satellites? You need a very small amount of C4 in the satellite to destroy the shuttle in the event of capture. Tampering with other entity‘s satellites can best be done with satellites. That also frees resources needed for bringing life support systems to orbit.
But at that point if you're building in a self-destruct for a weapon that can be so dangerous it's worth sending a shuttle to take it away from you, surely it's better to adversarially trigger the self-destruct and not bother sending the shuttle. So the C4 option might simply be a bad idea: make it more difficult and costly to remove your weapon, rather than triggering your own self-destruct.
There are easier cheaper ways of destroying a satellite than sending a space shuttle. We would have only sent a space shuttle to capture it for intelligence purposes.
Yeah well the standard degrowth argument against the efficiency camp is that more efficiency has always led to more resource consumption, not less (rebound effect). At least in capitalist markets. The current 'AI' boom, which is very relevant to resource usage, was only possible because integration and energy efficiency of graphics cards became efficient to a degree that was enough for neural networks to do anything meaningful with text.
There is a range header in the http specification for resuming downloads at a certain part of the file. Since http is stateless, you can download precisely what you need right away.
A grid of capacitive touch sensors could be printed directly on the pcb, bringing down costs by a degree of magnitude. Real switches are much more satisfying though.
I want to do a game like lights out. I'm thinking in 3d printing transparent caps and using dirt chip pcb switches and standard leds. The cost must be also down to 30 cts. Would be like a middle ground.
I can’t obviously. But if they don’t have enough, despite massive overdosing for years, that would be very surprising. (The test only shows one of three possible outcomes. It is not a quantitative procedure.)
Concur: that would be surprising. I was more focused on the possibility of having a dangerously high blood level which is fraught with negative sequelae.
This test — among many others — offer quantitative results at home:
Pretty expensive though. Lab costs in Germany are <20 € for a quantitative test and the cost of the physician for taking the sample is usually covered by insurance.
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