Real time sensor data via Bluetooth and plot on a scatter plot.

[Dineth Senevirathne]

Hello,

First of all a big thank goes to MIT App Inventor Developers and to the community for building this awesome gadget.

I am developing an indoor positioning system. I receive 2 values (x and y coordinates ) from arduino via a HC-05 Bluetooth module.I want to plot these two values on a  scatter plot in real time. I can develop an app to fetch the values via Bluetooth . But i'm stuck in plotting step. Your help is highly appreciated.

NOTE: X and Y values are NOT from a GPS sensor.

[Farzeen Harunani]

What do you mean, stuck? What are you trying to do, more specifically? 

[Dineth Senevirathne]

what i am going to do is ,

I have developed an arduino code which communicate some transceivers and calculate the two coordinate values x and y. 

Above values are floats. (eg. x=2.65)

I need to send these 2 values to an Android phone via Bluetooth and plot on a scatter plot.

I have successfully sent data to the android phone via an App Inventor app but still cannot plot these values in real time.

please help.

Here i'm attaching my .aix file. For now i am just fetch only one value from arduino and other values is randomly generated.

[Abraham Getzler]

This thread has been marked as duplicate with your other thread.

See attached for screen shots you should include for convenience of reviewers.

(They all have issues.)

Show us the .ino file from your transmitter,

especially the print and println() statements,

so we can judge data flow speeds and delimiter needs.

Your Clock1 is set to start firing at app startup,

even before BlueTooth connects.

That will cause problems.

Your Screen1 icon might be too large for install time,

judging by its size (a guess.)

You need to estimate maximum and minimum bounds for x and y

before you can start plotting, otherwise you can't scale them to

the ranges (1...Canvas1.Width) and (1...Canvas1.Height).

ABG