I need more Bits.

H

Hooter

Senior Member
Folks - I am using an 08M2 and I understand that there are 32 bit variables available - as stated in Manual 2:

b0 = bit7: bit6: bit5: bit4: bit3: bit2: bit1: bit0
b1 = bit15: bit14: bit13: bit12: bit11: bit10: bit9: bit8
etc...

My program requires up to about 48 bit variables to be controlled like this code snippet:

Code: 
if bit29 = 0 then pulsout c.4,5
else pulsout c.2,5
endif
if bit28 = 0 then pulsout c.4,5
else pulsout c.2,5
endif
if bit27 = 0 then pulsout c.4,5
else pulsout c.2,5
endif
if bit26 = 0 then pulsout c.4,5
else pulsout c.2,5
endif
if bit25 = 0 then pulsout c.4,5
else pulsout c.2,5
endif
if bit24 = 0 then pulsout c.4,5
Would peek and poke allow me to do the same as above or is there a better method available or perhaps a different Picaxe chip.
Any suggestions are always appreciated.
 
hippy

hippy

Technical Support
Staff member
A common trick is to move byte variables into b0 then use bit0 through bit7. For example -

b0 = b1
If bit0 = 1 Then B1_Bit0_Set
If bit1 = 1 Then B1_Bit1_Set
b0 = b2
If bit0 = 1 Then B2_Bit0_Set
If bit1 = 1 Then B2_Bit1_Set
 
W

westaust55

Moderator
Another option is to use the AND math function to mask so that you can check indivdual bits in any byte.
For example, say you are using the 8 bits in byte variable b5 then for the lower 3 bits:

Code: 
Bit0 = b5 AND $01 ; mask off to keep only bit0 in b5
IF Bit0 = 0 THEN
  ; Byte 5 Bit0=0 so do something
ELSE
  ; Byte5 Bit0=1 so do something else
ENDIF
Bit0 = b5 AND $02  ; mask off to keep only bit1 in b5
IF Bit0 = 0 THEN
  ; Byte 5 Bit1=0 so do something
ELSE
  ; Byte5 Bit1=1 so do something else
ENDIF
Bit0 = b5 AND $04  ; mask off to keep only bit2 in b5
IF Bit0 = 0 THEN
  ; Byte 5 Bit2=0 so do something
ELSE
  ; Byte5 Bit2=1 so do something else
ENDIF
 
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