PSP™ Tilt Sensor

[SuperAng]

I'm having a bit of unease with this project I'm working on. First off, I don't know if anyone knows Lua, but this is my program. It's fairly basic, but afterall, it only needs to read data from an accelerometer.

RED = Color.new(255,0,0)
WHITE = Color.new(255,255,255)
ORANGE = Color.new(255,102,0)
BLUE = Color.new(0,153,255)

screen:clear()

PROPORTIONAL = Font.createProportional()
PROPORTIONAL:setPixelSizes(0, 12)

BUF = ""
TEXT = ""
N1 = 0
N2 = 0
ORG1 = 0
ORG2 = 0
STATUS = "NOT INITIALIZED"
VERSION = "0.00.00:01 BETA"
A=0

while true do
screen:clear()

screen:fontPrint(PROPORTIONAL,5,10,"Device: "..STATUS,BLUE)
screen:fontPrint(PROPORTIONAL,5,30,"[START]: Exit",ORANGE)
screen:fontPrint(PROPORTIONAL,5,43,"[SQUARE]: Initialize device",ORANGE)
screen:fontPrint(PROPORTIONAL,10,56,"> [R TRIGGER]: Begin testing",RED)
screen:fontPrint(PROPORTIONAL,5,187,"PSP Tilt Sensor",WHITE)
screen:fontPrint(PROPORTIONAL,5,200,VERSION,WHITE)
screen:fontPrint(PROPORTIONAL,5,213,"SuperAng",BLUE)
screen:fontPrint(PROPORTIONAL,5,239,"http://PSPLua.com/SuperAng",ORANGE)
screen:fontPrint(PROPORTIONAL,5,252,"July 9, 2007",WHITE)

PAD = Controls.read()
if PAD:start()
then
break
end

if PAD:triangle()
then
ORG1 = N1 ORG2 = N2
end

if PAD:square()
then
A=1
System.sioInit(2400)
System.sleep(1000)
STATUS = "INITIALIZED . . . READY"
end

if A == 1
then

if PAD:r()
then
BUF = System.sioRead()
for i = 1,string.len(BUF) do
CH = string.sub(BUF,i,i)

if CH == "\r" or CH == "\n"
then

if string.sub(TEXT,1,1) ~= ":"
then
TEXT = "" CH = ""
end

if string.len(TEXT)>6
then
N1=tonumber(string.sub(TEXT,2,4))
N2=tonumber(string.sub(TEXT,5,7))

if N1 ~= nil and N2 ~= nil
then
X = N1-ORG1
Y = N2-ORG2
screen:clear()
screen:fontPrint(PROPORTIONAL,5,70,"X: "..X,WHITE)
screen:fontPrint(PROPORTIONAL,5,83,"Y: "..Y,WHITE)

if X<100 and X>-100 and Y<100 and Y>-100
then
screen:drawLine(X+344-5,-Y+136,X+344+5,-Y+136,WHITE)
screen:drawLine(X+344,-Y+136-5,X+344,-Y+136+5,WHITE)
end

screen.waitVblankStart()
screen:flip()

end

TEXT = ""
CH = ""

end
end

TEXT = TEXT..CH

end

end

end

screen:drawLine(244,36,444,36,WHITE)
screen:drawLine(244,236,444,236,WHITE)
screen:drawLine(244,36,244,236,WHITE)
screen:drawLine(444,36,444,236,WHITE)

screen.flip()
screen.waitVblankStart()
end

My first thought was that I would need some sort of external driver to read the serial port on the PSP (remote control for the headphones). But then I realized that it's being done within the program. But I'm confused as to how the program reads the accelerometer. Is it in turn reading the microcontroller? I don't know how the accelerometer sends data to the microcontroller, so I'm a bit lost. Anyway, take a look at the schematic and let me know if this is at all possible, or if it's just a hoax. Thanks.

(Schematic for PSP tilt sensor).

I have found a release of binaries for the PIC16F873 microcontroller. I don't know what to do with it, so maybe you guys can help. It's on www.kako.com (translate with Google.com first so you can read it), and look for "gravity sensor".