Hex digit verification

[HenrikOlsson]

Hi,
It looks to me like you have a two digit BCD value packed into one byte, is that correct?

I'm sure there are better and more clever ways of doing it but this seems to do what I think it is you're asking about:

If (CheckPanelDigit & 15) < 10 AND (CheckPanelDigit & 240) >> 4 < 10 then
'...more code here

Try it out and see if it does what you want.

/Henrik.

[kevlar129bp]

Thanks Henrick,

Sure is prettier than my code . As far as the BCD in a byte, yep, pretty much it. It can be any Hex digit in there. So, I just need to make sure each nibble in the byte is a number, not a letter. I'll give your code a shot in a bit. I'll have to intentionally read from the wrong address to make a go of it. On another quick note, would you have a quick and easy, down and dirty way to "flip" the 2 hex characters around? ie: HEX59 becomes HEX95. One of the panels I am working on stores its codes "backwards". Sneaky 'lil buggers. I need to flip 'em so I can display them on the lcd. I've got a routine working now, the low nibble - high nibble way, but just wondering if there was a better way?

Thanks again,
Chris

[HenrikOlsson]

Hi Chris,
You actually posted while I was typing my reply - I didn't see your own response.

Anyway, if you can afford two new bytes, lets call them Ones and Tens then you could do something like this instead (it produces slightly smaller code:

Ones VAR BYTE
Tens VAR BYTE
 
Ones = CheckPanelDigit & 15
Tens = (CheckPanelDigit & 240) >> 4
 
If Ones < 10 AND Tens < 10 then
'....more code here

This will then allow you to do something like:

SwappedValue VAR BYTE
SwappedValue = Ones << 4 + Tens

Which swappes the order of the high and low nibble in the byte.

/Henrik.

[kevlar129bp]

Very cool Henrick, thanks. When I get a second to try that code, I will. I'll report back asap.

Thanks again,
Chris