I need to create an app for iPad, where the client can make a signature and i can get coordinates, acceleration and pressure of touch. For draw, coordinates and acceleration no problem. but i can't get pressure. I tried with CPBPressureTouchGestureRecognizer but I didn't solve. I could also use a pen and a sdk.
Someone can suggest something to me? Can i do all with finger or it's necessary a pen? What is cheaper pen and easier sdk to use?
iPad has no hardware capability of sensing the pressure. Unless it'd be some special stylus that sends the pressure info via BT to the iPad app - you're out of luck.
Also - you'd have to calculate acceleration yourself.
Related
I developed an app which calculates distances between current position(lat and long) and another stores location. Current position comes from built-in Gps on iPhone. In some buildings is working indoor( like 8meters far from windows or doors). Why is it working indoor? How can I still get GPS signal without WiFi/3G/4G connection?
i hope someone can answer me
Welcome to SO.
The short answer is, it's out of your control. GPS is not reliable indoors. Sometimes you are able to get a signal, sometimes not. Metal frame buildings are worse than wood-frame buildings, and brick also tends to interfere with GPS signals. Florescent lights also tend to interfere.
In a given indoor setting you'll either get a GPS signal or not.
I'm trying to detect if my iPhone has been thrown into the air.I've tried using core motion's acceleration API and its altitude API.However, because the axes are fixed to the phone doing the detection of the changes is incredibly difficult.Is there a better way to do what I want?Is it possible to speed up the refresh rate of the CMAltitude API?
In freefall, you should see your 3 accelerometer values go to 0. Even in a projectile type of fall (throwing), the phone is in freefall as soon as it leaves the thrower's hand.
This white paper talks about using a MCU, but the concept is there.
http://www.nxp.com/files/sensors/doc/app_note/AN3151.pdF
I am writing an iOS app and don't want to start detecting for shake events until after my device has reached a certain speed. I know how to use CMMotionManager to get the CMAccelerationData to detect for shake events but does anyone know what i should use to detect how fast my device is moving? Either CMDeviceMoting/userAcceleration/GPS... i am just cannot find what i should do. I am writing my app in swift but answers in Objective-C will suffice as well.
Thank you for your help
You could use CoreLocation and use a CLLocation's speed property. This requires the device's GPS, and will only work for somewhat large speeds.
Using a stylus such as Jot Touch or Pogo Connect, how do I get biometric information such as coordinates (X,Y) pressure (T), stroke speed (S) when a user signs on the iPad (using Objective-C)?
Which method or libraries should I use?
The iOS SDK provides X/Y coordinates. It does not provide access to stroke speed or pressure.
UIPanGestureRecognizer computes a velocity, presumably simply by taking distance / time. Possibly it computes a moving average of distance/time. You can do that yourself.
The Jot Touch SDK provides access to pressure data if you are using a Jot Touch.
The Pogo Manager SDK provides access to pressure data if you are using a Pogo Connect.
If you want to support both styli, you will have to use both SDKs.
If you don't want to put your app in the App Store, you can use a private API to determine the touch size (which may be a good proxy for pressure).
Have you looked at the Jot Touch or Pogo API's? There are no Apple methods or libraries for this. Its 3rd party hardware. Apple does not have support for pressure. You can use the touchesBegan: and touchesMoved: functions to get x,y data on a touch and then calculate speed. You can also use gesture recognizers to detect movement and speed.
Ive been working with the iOS sensors a bit off late and i wanted to write an app that would accurately track the motion of the phone in space. I wanted to know if its possible to track the motion of the device and detect gestures, such as drawing a circle with your phone or even moving in a straight line.
I've been searching online about this, and i wanted to know two things:-
1.Is it possible to do this with the CoreMotion framework.
2.If Yes, what is the alternative for older devices that do not support CoreMotion. Without the double integral method using the accelerometer!
This would really help!
Any other alternative ideas are most welcome!
Thanks in advance!
As your write, you cannot do the double integral.
For gesture recognition, I would try dynamic time warping. See my earlier answer here.