In SX Microcontrollers, SX/B Compiler and SX-Key Tool, Joss451 wrote:

This problem has me, I'm afraid.

I'm using the professional development board with a BS2px24 and SX28AC/DP.

When I run the demo program for the H48C using the basic stamp, the reference voltage is pretty at 2046.

I wrote the following program to allow me to step through things as completely as possible.

Two things:

1) The reference voltage is fairly steady at 3127. The X, Y and Z voltages are nearly steady at (though X will fluctuate slightly):

X = 3120
Y = 3131
Z = 3580

Why would the reference voltage be so much different on the SX28 compared to the BS? Shouldn't it be the same?

2) When I single step through the code, I get readings that come out like (hex) 7FF, 85F, 87F, 9FF. The last digit is always an F. If I run it at speed and break on the last line, I get the above numbers. What am I missing?

I'm an old man newbie and am not seeing what I am missing. Any help would be greatly appreciated.

Best,

Joss


LIST Q = 37
DEVICE  SX28L, TURBO, STACKX, OSCHS2
IRC_CAL IRC_FAST
FREQ    50_000_000
RESET   0

Loop
  setb   rc.5			;Preset CS High

  mov    !rc, #%00000110 	;Set rc.5 to output

  clrb   rc.5			;Set CS Low

  clrb   rc.2   		;Set Data Pin low
  mov    !rc, #%00000010        ;Set Data Pin to output

  clrb   rc.1			;Set Clock pin low
  mov    !rc, #%00000000	;Set Clock pin to output
  
  setb   rc.2			;Send %11 
  setb   rc.1
  clrb   rc.1
  setb   rc.1
  clrb   rc.1

  clrb   rc.2			;Send %011
  setb   rc.1
  clrb   rc.1 

  clrb   rc.2
  setb   rc.1
  clrb   rc.1
   
  clrb   rc.2
  setb   rc.1
  clrb   rc.1

  clrb   rc.2			;Set data bit low

;Shift in
  mov   !rc, #%00000100		;Set data pin as input
  clrb  rc.1			;Set clock low
  mov   !rc, #%00000100		;Set clock pin as output

;Read thirteen bits back in
  
  clr   $0f

  setb  rc.1
  clrb  rc.1

  setb  rc.1
  clrb  rc.1
  movb  C, rc.2
  rl    $0f

  setb  rc.1
  clrb  rc.1
  movb  C, rc.2
  rl    $0f

  setb  rc.1
  clrb  rc.1
  movb  C, rc.2
  rl    $0f

  setb  rc.1
  clrb  rc.1
  movb  C, rc.2
  rl    $0f

  setb  rc.1
  clrb  rc.1
  movb  C, rc.2
  rl    $0f

  setb  rc.1
  clrb  rc.1
  movb  C, rc.2
  rl    $0f

  setb  rc.1
  clrb  rc.1
  movb  C, rc.2
  rl    $0f

  clr $0e
 setb  rc.1
  clrb  rc.1
  movb  C, rc.2
  rl    $0f

  setb  rc.1
  clrb  rc.1
  movb  C, rc.2
  rl    $0e

  setb  rc.1
  clrb  rc.1
  movb  C, rc.2
  rl    $0e

  setb  rc.1
  clrb  rc.1
  movb  C, rc.2
  rl    $0e

  setb  rc.1
  clrb  rc.1
  movb  C, rc.2
  rl    $0e

  setb  rc.5			;Set CS high to terminate the conversation

  jmp    Loop

---------- End of Message ----------


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