function fm476(varargin)

if nargin==1
    % Switchyard for the calback for the analoginput
    % samples acquired function
    saf(varargin{1})
    return
end

% initialize and reset
daqreset
clear all
close all

% Create Analoginput object
gui.ai=analoginput('winsound');
addchannel(gui.ai,1);
gui.ai.samplerate=22050;
gui.ai.samplespertrigger=inf;

% Update display every 1/10 seconds
gui.ai.samplesacquiredfcn='fm476(1);';
gui.ai.samplesacquiredfcncount=gui.ai.samplerate/10;

% Create Graphical User interface
gui.fig=figure('tag','gfig','deletefcn','fm476(2)');

subplot(4,1,1)
gui.p0=plot(NaN,NaN,'tag','gplot0');
subplot(4,2,3)
gui.p1=plot(nan,nan,'tag','gplot1');
set(get(gui.p1,'parent'),'ylim',[-11 11],'xlim',[0,gui.ai.samplesacquiredfcncount])
subplot(4,2,5)
gui.p2=plot(nan,nan,'tag','gplot2');
set(get(gui.p2,'parent'),'ylim',[-11 11],'xlim',[0,gui.ai.samplesacquiredfcncount])
subplot(4,2,7)
gui.p3=plot(nan,nan,'tag','gplot3');
set(get(gui.p3,'parent'),'ylim',[-9 9],'xlim',[0,gui.ai.samplesacquiredfcncount])

% Generate filters for our three defined bands using butterworth high order
% band pass filters.
[gui.bx,gui.ax]=butter(6,[400/11025 3200/11025]);
[gui.by,gui.ay]=butter(7,[3100/11025 5700/11025]);
[gui.bz,gui.az]=butter(7,[5700/11025 8200/11025]);

% Display the filters on the appropriate axes
[hx wx]=freqz(gui.bx,gui.ax,100);
[hy wy]=freqz(gui.by,gui.ay,100);
[hz wz]=freqz(gui.bz,gui.az,100);

subplot(4,2,4)
gui.p4=plot(NaN,NaN,'tag','gplot4');
hold on
plot(wx*gui.ai.samplerate/(pi*2),abs(hx)*500,'r')
set(gca,'ylim',[0 1500],'xlim',[0 gui.ai.samplerate/2])
subplot(4,2,6)
gui.p5=plot(NaN,NaN,'tag','gplot5');
hold on
plot(wy*gui.ai.samplerate/(pi*2),abs(hy)*500,'r')
set(gca,'ylim',[0 1500],'xlim',[0 gui.ai.samplerate/2])
subplot(4,2,8)
gui.p6=plot(NaN,NaN,'tag','gplot6');
hold on
plot(wz*gui.ai.samplerate/(pi*2),abs(hz)*500,'r')
set(gca,'ylim',[0 1500],'xlim',[0 gui.ai.samplerate/2])

% Initialization for 3D orientation of the device
[gui.b gui.a]=butter(5,30/11025,'low');
gui.gx=0;
gui.gy=0;
gui.gz=0;

gui.predat=zeros(1000,1);

set(get(gui.fig,'children'),'units','pixels')
set(gui.fig,'position',get(gui.fig,'position').*[1 1 1 2])

% Create 3D axis for displaying the decoded orientation
axes('position',[0.1 0.55 0.8 0.42])
gui.orient=plot3([0 0],[0 0],[0,-1],'-','linewidth',2);
patch([-1 -1 1 1],[-1 1 1 -1],[-1 -1 -1 -1],'r')
set(gca,'xtick',[],'ytick',[],'ztick',[]);
box on
set(gca,'xlim',[-1 1],'ylim',[-1 1],'zlim',[-1,1])

gui.check=uicontrol('style','checkbox');
set(gui.fig,'DoubleBuffer','on');
set(gui.fig,'userdata',gui)
set(get(gui.fig,'children'),'units','normalized')

start(gui.ai);


function saf(n)

    % In the future, it's going to be necessary to buffer around the region
    % we wish to analyze.  Keep 3 frames and analyze the central frame.
    gui=get(gcf,'userdata');
if n==1
    dat=getdata(gui.ai,gui.ai.samplesacquiredfcncount);
    dat=[gui.predat;dat];
    
    set(gui.p0,'ydata',abs(fft(dat)),'xdata',(1:length(dat))*(gui.ai.samplerate/length(dat)))
    set(get(gui.p0,'parent'),'ylim',[0 1500],'xlim',[1 gui.ai.samplerate/2])
    
    %Band Pass the raw data to isolate the channels (7th order butterworth
    %band pass filters
    datx=filter(gui.bx,gui.ax,dat);
    daty=filter(gui.by,gui.ay,dat);
    datz=filter(gui.bz,gui.az,dat);
    
    %limiting may help remove beat frequency noise
    if get(gui.check,'value')
        daty(daty>=0)=1;
        daty(daty<0)=-1;
        daty=filter(gui.by,gui.ay,daty);
        
        datz(datz>=0)=1;
        datz(datz<0)=-1;
        datz=filter(gui.bz,gui.az,datz);
    end
    
    set(gui.p4,'ydata',abs(fft(datx)),'xdata',(1:length(datx))*(gui.ai.samplerate/length(dat)))
    set(gui.p5,'ydata',abs(fft(daty)),'xdata',(1:length(daty))*(gui.ai.samplerate/length(dat)))
    set(gui.p6,'ydata',abs(fft(datz)),'xdata',(1:length(datz))*(gui.ai.samplerate/length(dat)))
   
    %FM Demodulation of the 3 channels
    demodx=fmdemod(datx,625,22050,2500);
    demody=fmdemod(daty,3125,22050,2500);
    demodz=fmdemod(datz,5625,22050,2500);
    
    %Filter out remaining noise from the AM component of the signal
    demodx=filter(gui.b,gui.a,demodx);
    demody=filter(gui.b,gui.a,demody);
    demodz=filter(gui.b,gui.a,demodz);
    
    if gui.gx==0
        gui.gx=mean(demodx(end-1000:end));
        gui.gy=mean(demody(end-1000:end));
        gui.gz=mean(demodz(end-1000:end));
        gui.predat=dat(end-1000:end);
        set(gui.fig,'userdata',gui)
        drawnow
        return
    end
    
    demodx=demodx(1001:end);
    demody=demody(1001:end);
    demodz=demodz(1001:end);
    
    % 0 = 0V for x,y,z
    % 1 = 3.263V for x,y,z
    % 
    
    Aref=3.263;
    Vz=5.28;   
    
    %Plot the demodulated acceleration levels.  Scale them assuming inital
    %acceleration is 1g in the z direction and that the values correspond
    %to increments determined by the data sheet.
    
    % Update graphics accordingly
    set(gui.p1,'xdata',1:length(demodx),'ydata',(demodx-gui.gx)*Aref/.120)
    set(gui.p2,'xdata',1:length(demody),'ydata',(demody-gui.gy)*Aref/.120)
    set(gui.p3,'xdata',1:length(demodz),'ydata',((demodz-gui.gz)*Aref)/.250+1)
    xaccel=sprintf('%1.1f',round(mean(get(gui.p1,'ydata'))*10)/10);
    yaccel=sprintf('%1.1f',round(mean(get(gui.p2,'ydata'))*10)/10);
    zaccel=sprintf('%1.1f',round(mean(get(gui.p3,'ydata'))*10)/10);
    set(gcf,'name',['Ax=',xaccel,'g     Ay=',yaccel,'g     Az=',zaccel,'g'],'numbertitle','off')
    
    xdat=[0 -mean(get(gui.p1,'ydata'))];
    ydat=[0  mean(get(gui.p2,'ydata'))];
    zdat=[0 -mean(get(gui.p3,'ydata'))];
    
    oldx=get(gui.orient,'xdata');
    oldy=get(gui.orient,'ydata');
    oldz=get(gui.orient,'zdata');
    
    if length(oldx)>15
        oldx=oldx(1:15);
        oldy=oldy(1:15);
        oldz=oldz(1:15);
    end
    
    scale=max(abs([ydat,zdat,xdat]));
    
    set(gui.orient,'xdata',[0 xdat/scale oldx(3:end)] ,'ydata',[0 ydat/scale oldy(3:end)],'zdata',[0 zdat/scale oldz(3:end)])
    
    gui.predat=dat(end-1000:end);
    set(gui.fig,'userdata',gui)
    
    drawnow

elseif n==2
    daqreset
    close all
end