You could probably use a voltage shifter circuit output to sample the voltages directly to the input of a supported sound board.
On Thu, Jan 28, 2010 at 6:27 PM, Ralph Becker-Szendy <[email protected]> wrote: > For one of my OpenBSD machines, I need to be able to measure a few analog > voltages, and act on them in a control process. The requirements are quite > simple compared to typical data acquisition: I absolutely need two voltage > inputs, either 0-20V or 0-100mV; doesn't have to be differential, > acquisition can be slow (1s is fine), and resolution can be as small as > 10-12 bits (1% accuracy is more than good enough). A few extra input > channels, more accuracy/resolution, and a few digital IOs wouldn't hurt, but > are not necessary. DIN rail mounting and connection breakout would be nice, > but can be improvised. > > On the software side, there will be OpenBSD, with ad-hoc monitoring and > control scripts. With a little programming and script-writing, I can adapt > anything that the OS can reasonably access. > > Now come the issues: I can't use PCI cards, only external units, most likely > connected via USB (as Ethernet and serial are expensive or rare). And it > needs to have some software support under OpenBSD - a Windows- or Linux-only > solution doesn't work. And this application is not worth spending thousands > of $$$. For Windows and LabView, solutions are easy to find (for example > EMant300, DAQPodMX, a variety of Omega products). Does anyone now of a > solution that would work with OpenBSD? > > -- > Ralph Becker-Szendy [email protected] (408)395-1435 > 735 Sunset Ridge Road; Los Gatos, CA 95033
