Saving Files

Saving Files

Waveform bitmap as saved by the qs-scope application to microSD card or USB flash stick.The qs-scope application running on your Stellaris EK board supports saving oscilloscope data on either an installed microSD card or a USB flash stick. Files may be saved either as Windows bitmap images showing the waveform(s) currently shown on the CSTN display or as comma-separated-value (CSV) files suitable for import into a spreadsheet application. The image to the right shows an example of a bitmap saved from qs-scope with all annotation features enabled.

CSV files saved contain 512 single channel samples or 256 dual channel samples. In each case, the trigger event occurs at the center sample - sample 256 for a single channel file or sample 128 for a dual channel file.

Saving to microSD card

The microSD card slot on the EK board can be found beneath the top left edge of the CSTN display. Hot-plugging the microSD card is not recommended. Install and remove the card only while the EK board is not powered.

To save a file to the microSD card, select either "CSV on SD" or "BMP on SD" from the "File" control group in the qs-scope menu. The application will save the file in the root directory using the next available filename of the form "scopeXXX.csv" or "scopeXXX.bmp" where XXX is a three digit decimal number starting from "000". A message will be displayed on the screen to indicate whether the save operation was successful or not.

Saving to USB flash stick

To save onto a USB flash stick, the flash stick must be connected to the EK board "USB Host" (EK-LM3S3748) or "USB OTG" (EK-LM3S3748) connector and the qs-scope application must be in USB Host mode. The USB operating mode is selected from the qs-scope "Setup" menu. Ensure that the USB flash stick is connected while the USB mode is set to "Device" then switch to "Host" with the stick already in place. With the current version of the qs-scope application, a flash stick may not be detected correctly if inserted while the application is already in USB Host mode. A message will be shown on the CSTN display when the application detects the USB flash stick.

To save a file to the USB flash stick, select either "CSV on USB" or "BMP on USB" from the "File" control group in the qs-scope menu. The application will save the file in the root directory using the next available filename of the form "scopeXXX.csv" or "scopeXXX.bmp" where XXX is a three digit decimal number starting from "000". A message will be displayed on the screen to indicate whether the save operation was successful or not.

Checking the disk contents

If you connect to the EK board using a terminal emulator connected to the virtual COM port offered by the "Debug USB" channel, the contents of the installed USB flash stick or microSD card can be examined while the qs-scope application is running. A command-line control interface is provided which includes simple implementations of the "cat" and "ls" commands.

The file system is arranged such that the microSD card is mounted as drive "0:/" and the USB flash stick as "1:/". To view the contents of the root directory on the flash stick, therefore, command "ls 1:/" can be used. If "ls" is entered without any path parameter, the microSD card (drive 0) root directory is listed.

To echo the contents of any text file from the file system to the terminal emulator, the "cat" command can be used. The single parameter provided is the fully qualified path to the file that is to be echoed, for example "cat 0:/scope000.csv" will read the first CSV file saved by the oscilloscope from the root directory of the microSD card.

Waveform bitmap saved using LMScopeSaving Files from LMScope

Bitmap and CSV files may also be saved from the Windows LMScope application. In this case, the bitmap saved is generated from the waveform data received from the EK board and does not contain the channel annotation information. An example is shown to the right.