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This is Newsletter #7 of the Open Instrumentation Project.

The OIP makes open-source software and economical high-technology
instrumentation hardware for students, hobbiests, engineers and
scientists.
The software and hardware run under Linux, Windows and Mac operating
systems. Current instruments include oscilloscope (with spectrum
analysis),
arbitrary/function waveform generator and Bode Plot network analyser.

Details of the project, hardware and software are at
www.syscompdesign.com

Our contact email is:

-- NEWS --

1. Education Resources Page, Pulse Oximeter Paper
-------------------------------------------------
We have added an 'Education Resources' section to the Syscomp web
site. This
now has 8 project documents for a variety of design exercises ranging
from
very simple to advanced. The most recent addition is a 'guided design'
document for a Pulse Oximeter, a non-invasive biomedical instrument
for
measuring blood oxygen level. We see guided design as intermediate in
level
between a structured design exercise and a completely open-ended
design. The
document provides hints and references while providing for flexibility
in
student designs.

2. New Application Note
-----------------------
Our application note 'Low-Cost Curve Tracer uses PC-Based Scope' is
now on
the web site. This paper describes how to create a curve tracer using
the XY
plotting facility of the DSO-101 USB oscilloscope and some simple
external
circuitry. An edited version is published in the February 2008 issue
of Nuts
and Volts magazine.

3. Scope Software Update
------------------------
The DSO-101 oscilloscope software can now repeatedly dump waveform
data to
disk at a user-specified interval. The data is in csv format, which
can be
imported into a spreadsheet.

Version 1.8 of the oscilloscope software has this feature and is
available
on the Syscomp web site at:
http://www.syscompdesign.com/download.htm
Source code is available from Sourceforge:
https://sourceforge.net/projects/oip

4. Arbitrary Waveform Drawing Software
--------------------------------------
The WGM-101 Waveform Generator can load and output an arbitrary
waveform of
256 8-bit points. A computer program can be used to generate an
arbitrary
waveform that can be described by an algorithm, but other types of
waveforms
have been more difficult to create. John Foster has now contributed
Wavemaker, a very nice Tcl/Tk program for drawing arbitrary waveforms.
It's available for download at:
http://www.syscompdesign.com/download.htm

We've used Wavemaker to create biological ECG, EMG and EEG waveforms,
which can be seen at:
http://www.syscompdesign.com/waveform.htm.

These waveforms were created by finding an example on the web, loading
it
into Wavemaker as a template, and then tracing by hand.

Once an arbitrary waveform is loaded into the generator, it can be
produced
at any frequency, amplitude and offset within the generator range.

Peter Hiscocks
March, 2008