topic Re: Read/Write sequence of bytes to UART in MQX Software Solutions

Read/Write sequence of bytes to UART

Paleantrop — Wed, 09 Mar 2011 18:52:07 GMT

Hi,

I am trying to write and read a sequence of bytes (e.g. : FF FF FF FF) to/from UART using M52259. Basically I have managed to write a program which sends characters and receive. I want to develop this one but, no success using integers. I have attached source files from the project with characters. Maybe someone can give me a hint (I am e beginner ).

thank you!

Re: Read/Write sequence of bytes to UART

ralu — Wed, 09 Mar 2011 22:18:37 GMT

To send integer you might set

response->DATA[0] = 'F';

response->DATA[1] = 'F';

response->DATA[2] = 'F';

response->DATA[3] = 'F';

as integers and on the other side you deserialise this response

int myint=1234567;

for(i=0;i<4;i++)

{

response->DATA[i]=((myint & (0xFF << (i*8)))>>(i*8));

}

and on other side when you deserialise

int myint=0;

for(i=0;i<4;i++)

{

myint |= (response->DATA[i])<<(i*8);

}

This way code is endian dependless and it only depends on fact that reciver has integers of size 32 bits.

If you know that both sides uses same endianess you can apply union when you serialise/deserialise.

http://en.wikipedia.org/wiki/Endianness

http://www.wellho.net/resources/ex.php4?item=c209/union.c

Re: Read/Write sequence of bytes to UART

Paleantrop — Thu, 10 Mar 2011 03:40:24 GMT

Thank you for the useful information!