Help please with Assembly (PBPro user)

[ScaleRobotics]

Here is some code to determine tilt using at least a two axis accelerometer. It uses trig.inc
This does not do the a/d conversions, or pulse measurement conversions, that would have to be added.

define OSC 20
'code working with PIC-MT-USB
include "TRIG.inc"

main:
define       LED     PortD.3

DEFINE LCD_DREG PORTD             ; Set LCD Data port                B C   D
DEFINE LCD_DBIT 4                 ; Set starting Data bit (0 or 4)   4 0
DEFINE LCD_RSREG PORTD            ; Set LCD Register Select port     A A
DEFINE LCD_RSBIT 0                ; Set LCD Register Select bit      3 2
DEFINE LCD_EREG PORTD             ; Set LCD Enable port              A A
DEFINE LCD_EBIT 2                 ; Set LCD Enable bit               1 5
DEFINE LCD_BITS 4                 ; Set LCD bus size (4 or 8 bits)   4 4
DEFINE LCD_LINES 2                ; Set number of lines on LCD       2 2
define LCD_RWREG PORTD
define LCD_RWBIT 1
ADCON1=15

TRISA=%00000011                         ' Set PORTA  0-1-3 used for AD
TRISB=%00000000                         ' Set PortB
TRISC=%00000000  
TRISD=%00000100  
'       Vdd     5 volts
'       Vss     Ground
'       Vo      20K potentiometer (or ground)
'       DB0-3   No connect

a   var word         
xresult var word      'result of accelerometer sensor in x axis
yresult var word      'result of accelerometer sensor in y axis
zresult var word      'result of accelerometer sensor in z axis
correct var bit        'able to keep equation the same, and flip angle
xdir    var bit          'shows direction of x tilt
ydir    var bit          'shows direction of y tilt
zdir    var bit          'shows direction of z tilt


Lcdout $fe, 1   ' Clear LCD screen
Pause 500       ' Wait for LCD to startup
toggle portD.3
                                     
xresult = 553                       'is 41 away from center
zresult = 297                       'is 215 away from center
'to try it on your calculator tan^-1(41/215) = 10.796543 degrees
                                    'xresult is acceleration allong the x axis
if xresult > 512 then               'get difference from neutral to gravity reading
    xresult = xresult - 512         'since we are using 10 bit result, half is 512
    xdir = 0
else                                'accelerometer reads 512 with no gravity
    xresult = 512 - xresult         'and above or below depending on direction tilt
    xdir = 1
endif

if yresult > 512 then               'yresult is acceleration allong the y axis
    yresult = yresult - 512
    ydir = 0
else
    yresult = 512 - yresult
    ydir = 1
endif

if zresult > 512 then               'zresult is acceleration allong the z axis
    zresult = zresult - 512
    zdir = 0
else
    zresult = 512 - zresult
    zdir = 1
endif

if xresult < zresult then           'if x/z is < 1 then x/z
    xresult = xresult * 30000       'we will have to correct angle if this is case
    y = div32 zresult
    correct = 0
else
    zresult = zresult * 30000       'else z/x to keep our equation within limits
    y = div32 xresult               
    correct = 1
endif
    x = 30000                       'multiply this by same value 30000 as above
call atan2
if correct = 0 then y = 9000 - y    '90.00 degrees - y = corrected angle

lcdout $FE,1,#y/100,".",#y//100," degrees"            'y = angle 1080 = 10.80 degrees
lcdout $FE,$C0,"x=",#xdir," y=",#ydir," z=",#zdir
end

here is the location of the trig.inc file

http://www.picbasic.co.uk/forum/atta...4&d=1234739854