Using the Digital Analog Slider

Attached is a .zip file containing a MediaLab 2008 experiment which uses our Digital Analogue Slider.

The slider is designed to take position snapshots at user-defined intervals. It communicates with the host computer over a standard serial interface at 19,200 baud, 8 data bits, no parity, no handshaking.

The slider is powered by an included 9-12v DC power supply, center positive, 200 mA.

The slider takes position snapshots as granular as 10 per second.

To activate the slider, send the ASCII string

{X}

The curly brackets are used by the slider to denote the beginning and end of a control packet, and are required. 'X' can be any number between 1 (snapshot every .1 seconds) and 9999 (snapshot every 999.9 seconds).

To stop the slider, send the command

{*}

The asterisk is the 'stop' character. Again, the curly brackets are required.

The slider can be started and stopped multiple times, and at multiple capture rates, during the same experiment:

{1}
{*}
{10}
{*]
{1}
{*}

The slider can change capture rates mid-experiment as well.

{1} <- snapshot 1/10 second interval
{2} <- snapshot 2/10 (1/5) second interval
{10} <- snapshot 10/10 (1 second) interval
{*} <- stop

MediaLab stores data from the slider in a simple tab-delimited text file called comdata.txt. This file is created when an experiment is sucecssfully completed. It contains time and position data for the slider and the two pushbuttons and stored in the 'data' folder for the experiment you're running.

Also note that the file comport.txt must be included in your experiment file. This text file contains data relating to the COM port, baud rate, etc. If you're using a serial port located somewhere besides COM5, change this text file to match.