This is Newsletter # 9 of the Open Instrumentation Project.
The OIP makes open-source software and economical high-technology instrumentation hardware for students, hobbiests, engineers and scientists. Current instruments include oscilloscope (with spectrum analysis), arbitrary/function waveform generator and Bode Plot network analyser.
CircuitGear
----------- In September of 2008 we launched CircuitGear, a combination Oscilloscope, Waveform Generator and Digital I/O. This new product has been very popular. We've since added features such as x1:x10 readout, Bode plot autoscaling and digital presistence - and fixed numerous bugs. The software is now at version 1.11. If you have an earlier version, we recommend upgrading.
As usual for the Open Instrumentation Project, the software is Open Source, licenced under the GPL, and runs on the Windows, Linux and Mac platforms.
Highlighted Feature: Generator Sweep Range
------------------------------------------ Back in the days of analog function generators, one of us spent many weeks struggling to make an audio sweep generator for a loudspeaker manufacturer. It had to sweep a 1000:1 range in frequency over the audio band and not drift like a thermometer.
Using the modern digital techniques of Direct Digital Synthesis , the Syscomp WGM-101 and CGR-101 can sweep over a range of frequency
1000000:1 (or any subrange of that) with a precision and accuracy of 0.1Hz. At the same time the DSO-101 or CGR-101 oscilloscope can plot the swept frequency response of a network over the same frequency range. This used to require a multi-thousand dollar rack of equipment. CircuitGear costs $180US, does arbitrary waveforms and can fit in a pocket. Some things do get better.New Application Notes
---------------------
Current and Power Waveform Measurement Technique, Useful hints on measuring current and displaying instantaneous power.
Oscilloscope Probes:Theory and Practice, Understanding the scope probe.
Pulse Circuits for Infrared LEDs and Visible Diode Lasers, A variety of pulse driver circuits for LEDs.
Pulse Oximeter Project Exercise, An example of a 'guided design' exercise for senior EE students.
Oscilloscope Development, 1943-1957, A history of early oscilloscope technology in North America.
-------------------- Details of the Open Instrumentation Project, hardware and software are at
If you have further questions or wish to be removed from this mailing list, our contact email is: snipped-for-privacy@magma.ca
Peter Hiscocks April 2009