Transcript Chris report

Current Works
• Downloaded XBee API firmware
– Was Freezing because correct setting was not selected
• Performed A/D conversion on all 4 XBee pins
• Set XBee to automatically perform A/D conversions every
millisecond
• Researched XBee API framing setup to determine how to
parse frames
• Began implementing parse code in MATLAB
– Having difficulty getting MATLAB to continuously read whole
frames
– Implemented a function to wait for start sequence of a frame;
Current code works fine for around 170 frames and then bytes
are shifted
– See next slide
• Initial testing performed with IMU
– Output voltage around 1.4 volts when stationary
– Determined resistor values for voltage divider
Matlab
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
firstbyte=fread(serobjw, 1)
while(firstbyte~=126)%first byte needs to be 126
firstbyte=fread(serobjw, 1);
end
i=0;
values=[0;1;2;3]%create vector
•
Need to add timer instead of just looping as fast as possible
while(i<2000)
bytes=serobjw.BytesAvailable;
if(bytes>28)%wait until 56 bytes read
ret = fread(serobjw, 56);%frame is 56 bytes
v0=[ret(47) ret(48)];
v1=[ret(49) ret(50)];
v2=[ret(51) ret(52)];
v3=[ret(53) ret(54)];
newvalues=[v0; v1; v2; v3;];
values=[values newvalues];
end
i=i+1;
end
What’s Next?
• Continue testing of accelerometer and gyroscope
output of IMU
– Connect 2 accelerometers and 1 gyroscope to XBee
with voltage dividers (could be used with Planar
motion)
• Continue work on MATLAB code for parsing XBee
frames
• Research other A/D conversion
chips/microprocessors
– Should be used in final version to read output from
third accelerometer and is more precise