Byte array indexing help needed

Don M

I have 2 byte array variables.

The TubeStatus[16] array contains byte values that are the equivalent of inventory counts of the 16 different bytes in the array numbered 0 - 15.

The TubeFull[2] array is a 2 byte array that is used as a flag to indicate which of the 16 tubes may be full.

What I am trying to do is read the value of each of the 16 bytes from TubeStatus and compare them to the number $32 Hex. If they are at $32 or more than I want to set the individual bit in TubeFull that corresponds to each byte from TubeStatus. In other words TubeStatus byte [0] would control TubeFull bit 0, TubeStatus byte [1] would control TubeFull bit 1, etc.

Here's the code I was trying but can't get to work:

pub  Tube_Inventory  | s, pos

  repeat pos from 0 to 15
    s := byte[TubeStatus][pos] 
    if s => $32
      if pos < 8
        byte[@TubeFull][0] := (%1 << pos)
      else
        pos := pos - 8
        byte[@TubeFull][1] := (%1 << pos)

I had thought about declaring TubeFull as a word and working some magic on shifting bits through the word but then I open another can or worms trying to break up TubeFull into 2 bytes so that it can be transmitted as 2 bytes instead of 1 word. My transmit method has a tx_block command but I can't seem to make it work.

pub  tx_block(pntr, n, ds)

'' TX block of n bytes / words
'' -- address of block is at pntr
'' --ds is data size: 1 for bytes, 2 for words

  repeat n
    if (ds == 1)
      tx(byte[pntr++])
    else
      tx(word[pntr])
      pntr +=2

Any and all help much appreciated.

Thanks.
Don

Phil Pilgrim (PhiPi)

Don,

Quick first impression: your statement s := byte[TubeStatus][pos] should read s := byte[@TubeStatus][pos].

BTW, if TubeStatus is delcared as a byte array, you can dispense with byte[@TubeStatus][pos] and just write TubeStatus[pos].

-Phil

Ariba

Declare TubeFull as a long and spilt it in bytes when you send it, that is much simpler.
Here is how Iwould do it:

pub  Tube_Inventory : i

  TubeFull := 0
  repeat i from 0 to 15
    if TubeStatus[i] => $32
      TubeFull |= 1<<i


'and in your send routine, send TubeFull bytewise:
  tx(TubeFull.byte[0])
  tx(TubeFull.byte[1])

Andy

Bits

• Mine requires no array

wrong posting, Dang pill confused me.

Don M

Phil Pilgrim (PhiPi) wrote: »

Don,

Quick first impression: your statement s := byte[TubeStatus][pos] should read s := byte[@TubeStatus][pos].

BTW, if TubeStatus is delcared as a byte array, you can dispense with byte[@TubeStatus][pos] and just write TubeStatus[pos].

-Phil

Phil- actually I did have the ampersand in my original code. Just forgot to type it in this posting. Thanks for the shortcut tips however.

Ariba- Thanks for your suggestion. I'll give it a whirl and see how I get along. Thanks again.

Don M

Thanks everyone. It works great!