How to convert ascii data to floating point?
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YoungMin Ho on 26 Nov 2016
Commented: YoungMin Ho on 30 Nov 2016
i have a problem with my project and i need your help.
the problem is about data type conversion.
i use an app to send gravity_sensor data via UDP on my phone.
This is a desription of the app i use.
The data is stored within the app as a float array. See the format below.
Format: [ X Acceleration, Y Acceleration, Z Acceleration, X Gravity, Y Gravity, Z Gravity, X Rotation Rate, Y Rotation Rate, Z Rotation Rate, X Orientation (Azimuth), Y Orientation (Pitch), Z Orientation (Roll), deprecated, deprecated, Ambient Light, Proximity, Keyboard Buttons 1 - 8 ]
and, i wrote these lines and get result in MATLAB.
this is the problem. what i wanted was floating point data like (-0.001). but, the result data type looked like ASCII code type.
so here are my question.
1) Is there any method to extract floating point data from a float array in UDP ?
2) if not, how can i convert ascii data to floating point?
i will wait your reply soon
The default for fscanf on UDP objects is %c format, but the packets do not contain text. You should be using fread() on the UDP object, specifying '*float' . You might also need to specify the endian order; see https://www.mathworks.com/help/instrument/byteorder.html
More Answers (1)
Image Analyst on 26 Nov 2016
That won't work. If you passed UDPComIn into fopen(), then it's a string with a filename in it. So you can't pass that in to fscanf. Anyway, you didn't even pass a file ID or a format specifier string into fscanf(). Check the documentation for fscanf(). Or use str2double() instead, if you can get your numbers in an ASCII string.
"If you passed UDPComIn into fopen(), then it's a string with a filename in it."
That is not correct. You can fopen() on Serial objects and TCP objects and UDP objects.
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