SPI Arduino (AtMega) Uno

[Anobium]

I am sure there is a smarter way!!!

[Anobium]

Untested. This should work.

Var = var XOR 0xff

[Chris Roper]

Var = var XOR 0xff

That will invert the Bits not reverse the order.

Without the ability to address the bit indirectly i.e. var.getbit your earlyer suggestion of tmp.0 = org.7 is the best bet.

[Chris Roper]

Untested but as I hate to shoot somthing down without offering an alternative here it is:

this function may work as requested:

Function ReOrder( DataIn as Byte ) as Byte
    Dim DataOut as Byte
    Dim NumBits as Byte

    For NumBits = 1 to 8
        Rotate DataIn Right
        Rotate DataOut Left
    Next

    ReOrder = DataOut
End Function

I have no hardware handy to test right now and it is almost midnight, but will do so in the morning.

Cheers
Chris

[Macgman2000]

I will give it a try!

[Macgman2000]

Anobium.

Thanks! It was tedious, but used cut and paste and replace function to do 3 bytes.

Nick

[Chris Roper]

Morning,

The Function works fine as is but for the sake completion here it is as a demo Program:

' ReOrder.gcb

#chip 16F877A

#option explicit

dir portB out
dir portC out

dim TestData as Byte

TestData = 0b10001100

PortB = TestData
PortC = ReOrder(TestData)

End

Function ReOrder( DataIn as Byte ) as Byte
    Dim DataOut as Byte
    Dim NumBits as Byte

    For NumBits = 1 to 8
        Rotate DataIn Right
        Rotate DataOut Left
    Next

    ReOrder = DataOut
End Function

The results in the Simulator are:

Cheers
Chris

[Macgman2000]

OK, I am lost in the function call. What is the significance of DataIn.....seems parameters were passed but I am not following what all is happening within. Anyone can shed some light?

-Nick

[Chris Roper]

Just feed it the byte you want reversed and it does so. i.e.:

ByteToSend = Reorder( ByteToSend )

Thats it.

It works by treating two bytes as 1 bit Stacks, each 8 levels deep, and the Carry flag as a variable.
But to use it you don't need to understand how it works, just accept it as some bit level trickary for now, or take a look at the help pages for the Rotate function and see if you can work out the trick from there.

Cheers
Chris