Accelerometer and led

' {$STAMP BS2} ' BASIC Stamp Directive
' {$PBASIC 2.5} ' PBASIC Directive
' -----[noparse][[/noparse] Constants ]----------------------------------------------------------
Negative CON 1 ' Sign - .bit15 of Word variables
Positive CON 0
' -----[noparse][[/noparse] Variables ]----------------------------------------------------------
x VAR Word ' Memsic x-axis measurement
y VAR Word ' Memsic y-axis measurement
side VAR Word ' trig subroutine variable
angle VAR Word ' result angle - degrees
sign VAR Bit ' Sign bit
' -----[noparse][[/noparse] Initialization ]-----------------------------------------------------
DEBUG CLS ' Clear Debug Terminal
' -----[noparse][[/noparse] Main Routine ]-------------------------------------------------------
DO
PULSIN 6, 1, x ' x-axis measurement
PULSIN 7, 1, y ' y-axis measurement
' Scale and offset x and y-axis values to -127 to 127.
x = (x MIN 1875 MAX 3125) - 1875 ** 13369 - 127
y = (y MIN 1875 MAX 3125) - 1875 ** 13369 - 127
[b][u]IF x << 010 THEN HIGH 5  'Here is my little addon <<<<<<~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~[/b][/u]
' Calculate and display Arcsine of x-axis measurement.
side = x
GOSUB Arcsine
DEBUG HOME, "x tilt angle = ", CLREOL, SDEC3 angle, CR
' Calculate and display Arcsine of y-axis measurement.
side = y
GOSUB Arcsine
DEBUG "y tilt angle = ", CLREOL, SDEC3 angle
PAUSE 50 ' Pause 1/20 second
LOOP ' Repeat DO...LOOP
' -----[noparse][[/noparse] Subroutine - Arcsine ]-----------------------------------------------
' This subroutine calculates arcsine based on the y coordinate on a circle
' of radius 127. Set the side variable equal to your y coordinate before
' calling this subroutine.
Arcsine: ' Inverse sine subroutine
GOSUB Arccosine ' Get inverse cosine
angle = 90 - angle ' sin(angle) = cos(90 - angle)
RETURN
' -----[noparse][[/noparse] Subroutine - Arccosine ]---------------------------------------------
' This subroutine calculates arccosine based on the x coordinate on a circle
' of radius 127. Set the side variable equal to your x coordinate before
' calling this subroutine.
Arccosine: ' Inverse cosine subroutine
sign = side.BIT15 ' Save sign of side
side = ABS(side) ' Evaluate positive side
angle = 63 - (side / 2) ' Initial angle approximation
DO ' Successive approximation loop
IF (COS angle <= side) THEN EXIT ' Done when COS angle <= side
angle = angle + 1 ' Keep increasing angle
LOOP
angle = angle */ 361 ' Convert brads to degrees
IF sign = Negative THEN angle = 180 - angle' Adjust if sign is negative.
RETURN