How can I do the same job that the simulink block "Byte Unpack" but in matlab not with simulink

Hi everyone,

I'm looking for functions in matlab or different ways to create a function which can do the same job that the simulink block "Byte Unpack".

I'm trying to unpack the input data message(uint8) to the unpacked output message (single) with 6 output ports dimension (See picture). But in my case I don't want to use simulink, only matlab code. The input data message come from to :

    Receiver = dsp.UDPReceiver('LocalIPPort',8080,'RemoteIPAddress','192.168.102.111',...
                                'ReceiveBufferSize',24,'MaximumMessageLength',24,'MessageDataType','uint8');

    DATAReceived = step(Receiver);

Any ideas? or suggestions?

Thanks,

Alexis

Answer 1

[Steven Lord]

I think some combination of typecast and swapbytes will get you close to what you want.

[Alexis Artuso]

Hi Steven,

First, thanks you to answer me so quickly.

I have never used swapbytes, i will test it. But how can I specify that i have 6 output ports dimension with this function?

[Steven Lord]

You want to know how to get 6 single precision numbers from typecast? Pass in a vector of 24 int8 values.

s = single(1:6)
in = typecast(s, 'int8')
s2 = typecast(in, 'single')

Take a look at the values in s and in with the display format set to "format hex" and you should see how they're related. You can also experiment with swapbytes on s and how that affects the values stored in in.

[Alexis Artuso]

Thank you ! My big program is working, it is perfect !