Description

This app lets you exfiltrate data that have been collected (using for example the Kiwi Microphone Data Collector) and saved on the .Now microSD card. Exfiltration consists of reading the contents of the SD card and streaming them via a serial link to a PC. You may use the Data Collector Host for the capture.

Compatibility

eMote.NOW 1.0, eMote version 4.3.1.12 and Visual Studio 2012.

Key Ideas

• Reading from the SD card.
• Streaming via serial link.

Setup

The .NOW used for exfiltration does not need any special wiring. Connect it to a PC via a USB cable. The PC should be configured for eMote .NOW development. See Getting Setup for more information. 

Make sure the COM port assigned to the .NOW is no higher than COM8; Windows sometimes has a problem with serial communication using larger numbered COM ports. You can check and change the COM port assigned by plugging the .NOW into the PC and using Control Panel -> Device Manager (search "Device Manager" from Windows Start). You should see a section labeled "Ports (COM & LPT)". Expand that section and check the assignment of the "Standard COM Port". To change it, double-click on the Standard COM Port and choose the Port Settings tab. Click Advanced and choose the COM port number in the drop-down control at the bottom.

If you find that the COM port you want to use has already been taken, proceed as follows:

• Back at Device Manager, click on the menu View -> Show Hidden Devices.
• Expand Ports (COM & LPT) if not already expanded.
• Right mouse click on the COM3 line (which should be light grey) and choose Uninstall.
• When done, click again on View -> Show Hidden Devices to hide them.

You can now assign the desired COM port to your .NOW.

If you look at this Exfiltrator program, you will see that the serial port used is COM1. This is the COM port number for the .NOW and bears no relation to the COM port used by the PC.

Operation

This assumes you are using the Data Collector Host program on a PC.

Install the microSD card used for Data Collector into the .NOW used for Exfiltrator. Remove it if necessary from the .NOW used for Data Collector.

• Attach the .NOW to the PC via a USB cable.
• Start the Host program. You can run the program from within Visual Studio in the usual way, or you can execute the binary directly: "Data Collector Host\bin\Debug\DataCollectorHost.exe".
• Respond to the prompts for COM port and file name. If you don't specify a path, the file will be stored in "Data Collector Host\bin\Debug\". An extension of .data is automatically added to the file name. You'll see the message to press Enter when ready to start receiving. Don't press it yet.
• Press the reset button on the .NOW. Wait until you see "conn" on the LCD display.
• Press the Enter key on Host to start receiving. You have 10 seconds to do this after you see "conn" on the .NOW. Exfiltrator will send the data from the microSD card to Host. Periodically you will see messages printed that give first and last values on each buffer's worth of data received.
• When done, Exfiltrator will display "0000" (all zeroes) and Host will print that it's finished.

• Suggestions

• Try incorporating the functionality of this app note into the Bumblebee Data Collector or Kiwi Microphone Data Collector. After collection is complete (the end-collection switch has been pressed), stream the results directly to an attached PC. If you want, you can even skip the steps of saving to Datastore and copying to the microSD card; as each sample buffer comes in, send it instead directly via the serial connection.