There is a wonderful device that can be easily attached to the navigation box under the front seat of a 2003-5 Prius (Prius II), or, with more difficulty attached to the Multi-Function Display for the case of no navigation option. It is the CAN-View (http://www.hybridinterfaces.ca).
Besides the great enjoyment of watching your Prius II's many operation parameters change on the MFD as you drive the car with CAN-View installed, you can record the parameters on a laptop or Tablet-PC computer as you drive and then view the parameters later as a function of time. This description of how to capture the data is for a Windows computer.
If your laptop/tablet-pc has only USB ports, you will need to purchase a USB to serial adapter. When it installs, note the com port number it is using.
Download and install the free RealTerm program (http://realterm.sourceforge.net).
After installing it, create a shortcut for it on your Windows desktop as follows:
"C:\Program Files\BEL\Realterm\realterm.exe" port=5 baud=115200 display=2 capfile=C:\Prius\test
Here I used com port 5 and a capture file name of C:\Prius\test ; you may need to change the com port number. (display=2 means hex) Do not forget to rename the files C:/Prius/test after doing a capture, so that you will not write over it the next time you do a capture. There is an option in RealTerm for added a new session to an old file, instead of writing over it.
For serial setup on the Prius CAN-View, set "Data source" to RAW .
Click on the RealTerm shortcut to start the RealTerm program with the parameters set in the shortcut.
Then click on Capture. If you want to see the data being captured in the terminal window, uncheck the Direct Capture box; then the data are captured from the terminal window. If your portable computer is slow, it may be best to leave Direct Capture checked; otherwise some data may be lost. You can tell that capture is going on by watching the hard-disk light regularly light up.
Then click on Start Overwrite or Start Append, depending on what you want to do.
Then, to actually start the capture, touch the "Output is" button on the MFD to change it from OFF to ON.
Drive around to capture data. Then to quit capturing data, touch the "Output is" button on the MFD to change it from ON to OFF.
Then click on Stop Capture on the RealTerm window.
A sample output file is at http://www.roperld.com/science/prius/raw.bin
For information about how I installed CAN-View in my Prius, see CANViewInstall.pdf .
Gary Morris has developed a program for converting the captured CAN data to a CSV file (http://en.wikipedia.org/wiki/Comma-separated_values), which can be read by Excel or some other equivalent spreadsheet program:
http://mggm.net/prius/candecoder.html .
-Dave Roper, http://arts.bev.net/roperldavid