Also be aware that Java has no unsigned ints
so you have to be especially overindulgent
when converting them from the TOS_Msg into
println()able elements, e.g.:
// ToByte -- TOS to Java
// Unsigned convert buffer at 'start'
// from a byte to Java int, without sign
public static int tb( byte[] buf, int start )
{
return ( buf[start] & 0xff );
}
Without the "& 0xff" the sign bit of the byte will
be extended into the full int return value.
MS
Sindra Dk wrote:
> thanks for your answer, i will try then i tell you if it works or not !!
>
> Sindra
>
> ------------------------------------------------------------------------
> From: [email protected]
> Date: Sat, 10 Apr 2010 23:50:42 +0300
> Subject: Re: [Tinyos-help] Error when receiving matrix values
> To: [email protected]
> CC: [email protected]
>
> Although I still don't see the whole picture, I think that your problem
> is that you are using 8 bits for every element.
> Now either it's 0:225 or -128 to +127.
> So you probably have declared the struct that you send as int8_t[][] array.
> Try to declare it as int16_t and don't forget that the default message
> payload size is 28 bytes.
>
> Arik
>
>
> On Sat, Apr 10, 2010 at 23:39, Sindra Dk <[email protected]
> <mailto:[email protected]>> wrote:
>
> Hi all,
> im working on copression algorithm and i use TinyOS 2.x
> i send an image from PC to mote i decompressed it then when i resend
> it to PC
> i get an error on its pixels value:
>
> Original matrix
> uint8_t A[i][j]={{172,132,4,39},{23,127,5,4},{44,7,6,9},{77,211,19,5}};
>
> $ java TestSerial -comm ser...@com5:telos
> Sending packet 0
> ser...@com5:115200: resynchronising
> Sending packet 1
> Received packet sequence number 1
> l'affichage est:-29 (wrong value)
> l'affichage est:26
> l'affichage est:-32
> l'affichage est:-17
> l'affichage est:-87 (wrong value)
> l'affichage est:19
> l'affichage est:-48
> l'affichage est:5
> l'affichage est:77
> l'affichage est:17
> l'affichage est:72
> l'affichage est:-18
> l'affichage est:-118
> l'affichage est:-4
> l'affichage est:85
> l'affichage est:-8
>
> ***************************************
> Display matrix as C is:
> 227 (this is a true value)
> 26
> -32
> -17
> 169.5 (this is a true value)
> 19.5
> -48.5
> 5.5
> 77
> 17
> 72
> -18
> -118.5
> -4.5
> 85.5
> -8.5
> i don't know why i can't display values higher than 127!!!
> can any one help me please? and thanks in advance.
> Ragards,
> Sindra
>
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>
>
> --
> Best Regards,
> Arik Sapojnik
>
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