accelerometer android query - android

i need to develop an app that needs data from the accelerometer. could some one please suggest which android phone in the market would be good enough for accurate accelerometer data generator. since the entire app is based on data fetched by the accelerometer, the device has to be pretty accurate.

The accelerometers in any smart phone are cheap and the difference in the accuracy of the readings is negligible. Even though these devices are cheap, they're very accurate and can output a few thousand readings per second - so the accuracy of your program is going to be dependent on what you DO with the readings in your code not by the device itself.
If you just want an Android phone for development - not to use with a wireless plan, then go to ebay and swoop a used one up for $30-40. Most of these phones have accelerometers in them, but before you buy it - google the model and make sure.
I own a G1 - the original Android phone, and the accelerometer is very accurate.

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altbeacon RSSI on different devices

I've done some experiments on different devices and I made each of the scanner and receiver at the same time and saved RSSI get from other nearby devices but the result was strange. first, there was a Huawei p6 that could scan other devices signal but nobody could see its transmit signal. second, the RSSI was completely device-dependent although beacons setting was the same for all of them inside the application and I want these signals to approximate their distance from each other.
question is that is this library reliable for my purpose which is getting approximately distance of devices from each other? I should mention that these results have gotten from android devices and I think that iPhones are another problem
The fragmentation in Android devices means that there is a huge variation in not just bluetooth chips, but in the external bluetooth antennas and phone cases that affect the strength of the signal Android devices receive and transmit.
While the distance estimates provided by the Android Beacon Library are useful for finding the relative distances to different beacons, using the value as an absolute distance estimate will not be consistent across different Android devices. The library does provide a way to tune its distance estimates to a specific hardware model, but unless you are targeting only a small number of devices this approach is not practical to tune for thousands of Android models out there.

Android sensor accuracy

I made an android app that relies heavily on very accurate sensor data (magnetometer, gravitymeter and accelerometer). To achieve this I validate all these device sensors periodically for highest quality of service by checking the sensor status for SENSOR_STATUS_ACCURACY_HIGH. If one of these sensors doesn't have this status I show a calibration screen until the high accuracy can be delivered. On my own device this is working perfectly fine, but I get a lot of app reviews from people who can't get around my calibration screen. My question is, can I rely that every android device is per se capable of delivering SENSOR_STATUS_ACCURACY_HIGH or do I have to lower the minimum accuracy? If so, how is this status even defined cross devices?
No, you can't. And even if you could, its possible for the sensor to be broken and returning the high status incorrectly. And you don't know if OEM A and OEM B have the same definition of high. In the end, you're trusting the individual hardware drivers for each device, and hoping all of them are both acting in good faith and had the same definition of "high accuracy". Neither of which are really reliable.

Bluetooth Low Energy (BLE) - Limit advertising distance for all Android devices

I and a couple of friends have got a list of requirements for a new project. This project, basically asks us to synchronize a specific directory in a laptop with the user's phone (just like dropbox does) but using BLE for the communication.
Everything is working as expected. We're using Android on the phones and a BlueGiga USB dongle on the laptop side. The only problem we're facing is that we cannot limit the distance in which the phone is detected.
We do know that we can modify the TX Power and also the Advertising mode as it's explained here (https://developer.android.com/reference/android/bluetooth/le/AdvertiseSettings.html). The real problem is that we cannot get the same max distance on every phone because of differences with the chipsets, antennas, etc throughout all the Android devices in the market.
How could we do to limit the connection distance to 1 meter for all the devices running Android? We'd need to rely on the RSSI values but I'm open to different approaches anyway.
Thank you very much in advance guys and remember that everything is working perfectly. We just need to adjust the max distance.
Thanks.
Max.
Simple answer: You can't get an absolutely exact range limitation because of the physical properties of electromagnetic radiation. There are so many things you have to take into account, which makes it a quite difficult and complex task.
What you can do is very sophisticated calculations based ony many different factors to get an approximation. As already mentioned in the comments, you might find helpful libraries with algorithms and formulas for well known devices, chipsets antennas etc. so you don't have to do all the calculations on your own.
With the help of some libraries and tools, you may be able to quite safely determine if the device is within a range of between 1 and 3 meters.

How to access Galaxy S5 temperature sensor?

In the manual on the page 19 there is an info on temperature sensor in S5.
Temperature and Humidity sensor allows your device to read both
temperature and humidity conditions. This is useful to calculate
calories burned within S Health
But I cannot seem to find any data on how to use this sensor.
Did anyone find any way to use this sensor in our own app?
EDIT
Take note that if you install any 3rd party temperature application, it will say that your device (S5) does not have temperature sensor. So I cannot use the standard code to access the sensor because sensor is not being detected. But Samsung app S Health is using this sensor and I am not sure which API it uses.
Galaxy S5 does not have Temperature and Humidity sensors, unlike S4. Samsung announced it and close to publishing decided not to ship it. It seems that the reason was the fact that these two sensors could not work along with water-proof feature.
S Health app has ability to measure body temperature but its API is hidden at this moment. It means that we have no clue if it measures temperature via external devices (Gear) or it can measure it using heart-rate sensor. Also we don't know if it can measure air temperature (probably not).
http://developer.android.com/reference/android/hardware/Sensor.html#TYPE_AMBIENT_TEMPERATURE
I think this is what you're looking for

Nexus 5 gps update rate

I have a GPS logger app I have wanted to make for a few years now. My old phone could never do it (HTC Desire Bravo A8183) as the GPS update rate was only 1Hz. Friends are telling me their Samsung and iPhones can do 5Hz GPS now. I have installed the same app I used in my HTC in my Nexus 5 to measure the GPS update rate and I am still getting 1Hz as the standard update rate from the Nexus 5.
At first all I want to make is a position recorder that saves GPS coordinates to the onboard storage. For this application power use does not matter, as using a USB car charger at the same time would make sense. It also does not matter if the 'phone' functionality of the device is impaired whilst the app is running.
My idea is to make something for personal use similar to a GoPro with inbuilt GPS logging. GPS would give you location, and distance over time gives you speed, and delta speed over time knowing weight and drag co-efficient gives you horsepower. I already know the Cd and CdA and running weight for my race car.
Anyway how do I get the phone to poll the GPS more often? Do I need to root kit the phone and then install some obscure hack? Or is it not possible?
I need accurate data in the 4-10Hz range or I may as well just forget about making this. I'm pretty sure I can buy a bluetooth GPS 'mouse' that does this but it would be much more practical to use the phones internal hardware.

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