Author: Joseph Toles
Date : April 18, 2013
Phone: (425) 269-7168
Email: jbtoles@gmail.com


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| Sections             |
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1. Install drivers
2. Using "main"
2. Notes


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| 1  INSTALL DRIVERS   |
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This section explains how to install the drivers necessary to run this program.

Plug the LabJack into the computer using the USB cable.

Go to http://labjack.com/support/u3 and click “Linux Package”. This will download a compressed folder called “exodriver-master”. Extract it. Open the extracted folder. There are instructions in the “README” and “INSTALL.Linux” files but you don’t need them. Follow these instructions to install the drivers.

Once you have installed the drivers, go into exodriver-master’s “examples/u3” folder. Enter the “make” command. Run “u3EFunctions”. If it works you’re ready to go.


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| 2  USING MAIN        |
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To run the standard program ented
$ ./main
This will display the present temperature, pressure and other information along with a graph.
To suppress the graph, pass the "-t" flag to main. Main will always create a log of the information it records. This log is saved in the logs folder with the current timestamp as its name.
These logs are written in plain text format and so can be examined with a standard text viewer, however it is easier to view them visually. To do so, use the plot program. For example
$ ./plot logs/2014-04-11_17:17:12
will display a graph of the temperatures in the 2014-04-11_17:17:12 log.
Temperature is the default. Passing a "-p" flag will display pressure instead. passing "-vt" will display the raw voltages of the RTDs instead of temperatures. "-vp" will display the raw voltage of the barometer instead. As the system has evolved, the equations to calculate pressure and temperature form voltage have changed. This means that in viewing some old data, temperature and pressure may need to be recalculated. To do this, pass the "-r" flag.
There are two more flags. "-f" displays the fraction of pressure divided by temperature. "-o" dosplays the resistance of the RTDs calculated from the voltages in the file.



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| 2  MISC NOTES        |
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The U3 Labjack manual can be found at
http://labjack.com/support/u3

After building the binary, you must run "do-suid" as sudo user. This give main the permissions necessary to access USB ports.
If you get the error
   "libusb error: LIBUSB_ERROR_ACCESS
    Open error: could not find a U3 with a local ID or serial number of -1
    error: could not open USB connection."
It is very likely because you did not give main the proper permissions. Run "do-suid" as sudo user to set these.