ascii conversion help needed

[Darrel Taylor]

What you need is the Bitwise operators "&" + "|" (OR).

Since you only want to output the lower bits of PORTB, you have to read PORTB first, mask out the lower bits, then OR the new bits in.

portb = (portb & %11110000) | (var & %00001111)
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[muddy0409]

Hi Darrel,
I've been up all nite trying to sort this thing out. Let's see if I can explain where I am ATM:

I've got 5 bytes coming in as 5 hex2 numbers.
I am taking the low nibble of each of those as hex1 numerals.
Gotta then convert then to dec1 digits and write them to port b low nibble.
I think I've got it sorted...

I don't think I will need to read, mask, or, then write portb as there is a set sequence that needs following, but that will be another problem, probably.
I just gotta write the low nibble with the high nibble all 0's and then do some bit manipulation with the high nibble. Should be pretty easy.

Famous last words huh?

[flashg]

Im not sure if this is what you need but, it is a simple Ascii to hex converter. This assumes the stringbyte is limited to valid hex characters.

ConvertAscii_to_Hex:

StringByte = StringByte - 48
Lookup StringByte, ( 0,1,2,3,4,5,6,7,8,9,0,0,0,0,0,0,10,11,12,13,14,15) , Returnbyte

Return

[muddy0409]

Rightyo, thanks for all the help blokes. I got it all sorted out.
It may not be pretty, but it works a treat.

And it fits in the codespace.