String & WRITE

[mpgmike]

Whether you wish to refer to a value in its decimal, hexadecimal, or binary format, when storing to the EEPROM, you are simply storing that value. When you READ it back, you may need to format it in its hexadecimal format for sending information serially, or displaying to an LCD. It looks like you are receiving these digits as ASCii, which allows for letters A-F. My approach would be to first convert the ASCii characters into Nibbles, then group them together into Hex. Finally you can store the Value in your EEPROM.

To convert an ASCii character to a Hex nibble, subtract $30 from the numeric value of that nibble. Characters 0 >> 9 will be their 0 >> 9 raw value. Capital letters start at $41. Example, actual ASCii value of $41 = "A". You could use IF New_Data > $39 THEN : GOSUB DecodeLetters, ELSE : GOSUB DecodeNumbers. Using the shift and mask code listed previously, group your high nibble and low nibble together to create a new and complete byte value. Repeat for each 2-character grouping. When READing from the EEPROM, use the HEX modifier to send "Value" serially (ASCii representation). The key is that your ASCii value is $30 + Numbers (0 >> 9) and $37 + Letters (A >> F); conversely, ASCii - $30 = 0 >> 9 value while ASCii - $37 = A >> F values.

[HenrikOlsson]

When you use the HEX modifier with SEROUT, DEBUG, LCDOUT, HSEROUT, ARRAYWRITE and so on it converts FROM a numeric value TO an ASCII string representing the numeric value as hexadecimal. In other words a value of 127 becomes a "7" and a "F".

Likewise, when you use the HEX modifier with SERIN, DEBUGIN, HSERING, ARRAYREAD etc it converts FROM an ASCII string (or single character) representing a numeric value as hexadecimal TO the actual numeric value. In other words the "7" and the "F" becomes 127.

mpgmike does a good job of explaining how you convert ASCII to the numeric value that the "text" represents but what I'm trying to say is that you don't have to do that "manually" because the HEX- (and DEC and BIN) modifiers works both ways and does the job for you when used with a command that supports them (which DEBUGIN does).

It would be interesting to see if any benefits (size- or speedwise) can be gained from doing the conversion "manually" instead of letting PBP handle it for you using the built in modifiers.

Happy new year by the way!

/Henrik.

[Andrew]

Hello everyone,

I am glad that my "initiative" to re-open this topic has got such an echo.
Will give a try to presented methods and will reverd with results ASAP.

Meanwhile have a joyful and prosperous New Year !