I am a newbie in android.
Just wondered how gyroscope works in android . Is it any hardware that is mounted inside or what exactly it is ?
Also, would like to know if gyroscope and accelerometer sensor are in anyway related ??
Thanks in advance !!
As for your first question, Google "gyro MEMS". For example, you will find An Overview of MEMS Inertial Sensing Technology.
Your second question is answered here.
Gyroscopes is the device which measures the rate(angular speed) change and Accelerometer measure the change in speed in x,y and z directions.
These devices has internal mechanism(made up of capacitors,filters, ADC components and an interface(I2c, spi)) to carry these analog outputs to digital world where they are interpreted by the software(sensor fusion libraries).
In the device (phone or tablet) they may or may not be present as a separate module(chip) but sure they are connected to the MCU of the Phone either directly or Via some target MCU(to which they are connected via interface like I2C or SPI).
No Gyroscopes and Accelerometers are not related in any way but their data when combined together on the basis of certain algorithms(of what sensor fusion libraries are made up of) gives the orientation of the the device and may help to flip the screen owing to their output.
-Rp
Related
I am using a old phone running android 4.0.4 that has the following sensors (printed by using TYPE_ALL in android studio):
Accelerometer Sensor
Magnetic Field Sensor
Proximity Sensor
Orientation Sensor
According to the android documentation on composite sensors this phone should be able to output linear acceleration, however when i ask for it, only null is returned. Other simple sensors such as accelerometer or magnetometer work fine (the basic sensors that are fused to obtain linear acceleration).
The code so far is pretty basic, it's just printing values.
Any idea why this happen? is this standard behavior? Are not all available sensors to a smartphone supposed to be implemented?
The sensors that are specified as hardware/software behave differently according to the sensors available. If https://developer.android.com/guide/topics/sensors/sensors_overview.html#sensors-identify says software, it is the developer responsibility to use the android API to fuse the right basic signals into the composite signal you are looking for.
I am creating a thermometer app in android when I test on Galaxy S3 it shows that
TYPE_AMBIENT_TEMPERATURE NOT Available
TYPE_TEMPERATURE NOT Available
I want to know that Galaxy S3 has above sensors or not? or How I can solve this issue to get temperature ?
As Yohannes said in the comment you can only calculate standard atmospheric temperature which is not useful to for daily use mostly used in aviation.
Here is the temperature estimation vs barometric height. http://home.anadolu.edu.tr/~mcavcar/common/ISAweb.pdf (page 2).
It seems only way to use an external temperature sensor with bluetooth or similar stuff and require this sensor in your app promotion.
This is really cool one:
http://www.bee-wi.com/bbw200,us,4,BBW200-A1.cfm
An easy way to check if a sensor exists on a specific target phone is to install an app like AndroSensor. This will list all the available sensors.
I doubt if the underlying sensor is missing you'll be able to do much. You can use a weather service to get the current temperature of the device's location but that won't help with a thermometer.
Not sure if this also applies to the Galaxy S3, but you can try to look for sensors with a type value above TYPE_DEVICE_PRIVATE_BASE. Many phones (for example Nexus 5x and Pixel 3) have one or even multiple sensors that exhibit a temperature reading through this and you usually can tell by the name of the sensor (for example "BMI160 Temperature" or "BMP380 Temperature", both on a Pixel 3).
These "vendor defined sensors" are usually from sensors that require a temperature reading for compensation/calibration (BMI160 is the IMU and BMP380 the barometer of the Pixel 3). Especially barometers are very likely to have a temperature channel.
However, there is a good reason that the manufacturer does not offer these temperature readings through the official TYPE_AMBIENT_TEMPERATURE type:
Placing a thermometer inside an enclosed device that heats itself from the inside is not a good method to measure the ambient temperature. Especially if the temperature reading is only meant to compensate temperature drift of the sensor, you will not get anything useful as you mostly measure the temperature of the inside of your phone. Even if a phone officially measures ambient temperature, the results will not be very precise for the same reasons.
I want to make an app that need to use Gyroscope Sensor
However, due to cheap android phone didn't provide this sensor but it still have accelerometer and digital-compass in itself.
As far as I know.. Since, accelerometer can detect 3 axis of our phone. When compare to Gyroscope, only the thing they lack is they can't detect if user rotate their phone without changing their pose. That's why I need to use digital compass to get the north direction to solve this problem.
So, I would like to know is it possible to just use only these 2 sensors to make a gyroscope sensor work-like? Anyone ever try? Is it actually work?
Thanks
It is not clear why your app needs gyroscopes. I assume that you want to track the orientation of the phone.
You can track the phone orientation reasonably well with the accelerometer, compass and a low-pass filter. It lags a bit but it works, I have impleneted that for the Shimmer platform. See also my answer here with the link to a demonstration video.
In my project, I want to detect if a user is moving or not by using either wifi rssi or accelerometer sensor.
What I should do to achieve that?
It actually all depends on what kind of movement you want to detect.
WiFi RSSIs : From a starting position and scan results (initial RSSIs for newly discovered access points), you can check through time their evolution in term of signal quality. A short displacement of the user will not be easy to find as RSSI values are tweaked by a large amount of parameters (orientation, obstacles, setup of the room, atmospheric conditions, people around). Thus you would need averaged values (scans must then be performed quickly to have enough data) and leaving an access point perimeter would make you lose the information.
Accelerometer : Depends on what quality of sensor you are using. If you're using embedded sensors within smartphones, it will be tough. Their accuracy is bad, and as you'll need to integrate its values (m/s² to get m/s) the error will grow subsequently. Plus it might be hard to discern real user movement from the device's tilt if you're using a mobile phone or tablet.
Without really knowing the details of your projet, I believe that RSSIs should be easier to use if you actually need to detect not so tiny motion. If you want something more precise, you'll need some way bigger research work.
See Android accelerometer accuracy (Inertial navigation) for RSSI-based indoor localization.
is there a way to root my Android phone and get sensorinformation direct from the sensor or system?
LG marcel
I don't really know what you mean by getting the information in a "direct" way.
There are two types of sensors in the android sdk: sensors representing an actual hardware sensor (e.g Sensor.TYPE_ACCELEROMETER) and virtual sensors like Sensor.TYPE_LINEAR_ACCELERATION which values are calculated based on the data of one or more sensors. Using the sensor types which represent real hardware allows you to read the data delivered from the sensor The problem with all kind of sensors in smartphones today is that there might be some kind of preprocessing (e.g lowpass filtering) involved and there is little documentation on where and how this is done as there is often no information on which sensor is used the device. I recommend reading this article on android sensors.
Hope this helps...
In android, you have the SensorManager class which give you the possibility to work with your sensors on the device (except the GPS and the camera sensor).
To understand how it works, see this:
http://developer.android.com/reference/android/hardware/SensorManager.html
If you have questions abaut this, feel fre to post them.