Ascii string to Hex string..problem

[bartb]

Hi all,

I have a problem concerning the asci to Hex conversion. I read an ascii code from my serial port. ( ascii caracters...)  When I select hex display in my string indicator i get the hexadecimal string that i need(0001 2822 2670 0001 2821 2270)... But i only need 3 digits of the Hex code (character 8 (offset 6) character 6(8) and 6 (10) And those characters need to be individually converted to decimals.. But  this can be achived by using the hex string to nr.

thnx in advance

B Bakels

[GerdW]

Hello Bart,

it seems you only need nibbles of the received string...
Two ways:
1. Convert the numbers (=ascii codes) to a hex string and get the appropriate chars by using 'string subset'.

2. Do masking (=AND appropriate bits) and shifting (move upper 4 bits to lower bits, if needed) and do the conversion for each single digit on it's own.

Pretty straight forward number conversion.

[pincpanter]

What you see with hex display is actually a representation of the string content. Each character in the representation is not a character in the string, rather it represents a nibble, or half-character (4 bits).
In your example, the string does really contain 12 characters: 00, 01, 28, 22 etc.
Are you sure you need individual nibbles in the string?
Anyway, with the conversion function String to Byte Array you may get an U8 array with 12 elements, with values (in hex) 00, 01, 28, etc., i.e. (in decimal) 0, 1, 40, etc.
From these values you can extract any nibble you want, ANDing a U8 value with hex 0F to get the low nibble, Shifting the U8 by -4 to get the high nibble.

[tbd]

Hi Bartb,

      IF a "28" always represents an "8", and likewise with the other digits, maybe this would work? 

The For-Loop handles multiple 6-char sequences...

Regards.

Message Edited by tbd on 07-03-2006 03:57 AM

[bartb]

HI

Thnx all for the info.. The Way TDP uses. was the same i idea i got 10 minutes ago :P. I think this is working well... Thnx

Bart

Message Edited by bartb on 07-03-2006 01:11 PM