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Integrating external lm_sensor data into PicoLog

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Integrating external lm_sensor data into PicoLog

Postby Julian » Thu Oct 30, 2008 12:38 pm

I'm trying to analyse computer cooling so I'm considering getting a TC-08 so that I can analyse air temperatures at various places in a computer chassis. I would also like to integrate data from integrated motherboard and CPU sensors common in PC equipment.

My systems under test are running Linux and I currently access the on-board and on-chip sensor data by using a perl script to executing a Linux lm_sensors command every 30 seconds and then having the perl script extract and format the data I am interested in.

My question is, what is the easiest way for me to inject lm_sensor data into PicoLog so that I can graph it against the thermocouple temperature readings that I collect via a TC-08. Although I am a trained computer scientist I prefer to take the simplest possible approach rather than needing to get myself a C++ development environment set up or similar.

My initial though/hope is that maybe PicoLog has built in capabilities whereby it can poll a text file at a pre-defined frequency where I could just write values, maybe in some sort of <Name> <Value> format, and that PicoLog could then treat that file as if it was a measurement device. Clearly I would have horrible latency between the actual time that a CPU sensor is read and the time that PicoLog actually sees the sample but I'm not too bothered about that and could probably visually correct for such timing skews when looking at the graphs.

Has anyone done anything like the above and what would people suggest as my lowest-effort way to get this lm_sensor data seen by PicoLog?

- Julian
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Postby Julian » Sat Nov 08, 2008 10:55 am

Well, I guess it's not encouraging that I got no reply, it leads me to think that what I want to do isn't possible but I'd like to check a few things explicitly.

The manual for PicoLog says in section 1.2 on page 1, in the 8th bullet point "Can analyse other files during data collection". This was exactly the feature I was hoping would work for me but I don't see any further reference to it in the manual and from playing with the demo version I can't see anything that might do this so what is this feature?

The only thing I thought it might be was to do with taking scaling data from a file but I'd assumed that for speed reasons that a scaling file is read once and then cached for the duration of data collection and graphing. If it really is parsed on each sample collection then, as long as it's not locked for access by PicoLog, then I have an idea on how I could use this to do what I want but I won't bother typing it all out until I hear that it's not cached because I strongly suspect that it must be.

There are various software examples to download but they all seem to relate to device drivers or interface software allow other software to talk to the physical hardware devices sold here. What I was hoping for was that the PicoLog software itself had some sort of modular structure whereby, if I really can't do what I want with built in functionality, then I could write a "device driver" to install into PicoLog that would implement a virtual converter presenting channels of data to PicoLog where the data was actually being generated by my perl scripts polling the onboard motherboard and CPU sensors for the systems I test. Is there in fact no way for an end user to write this sort of PicoLog driver?

- Julian
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Postby Robin » Mon Nov 10, 2008 2:27 pm

Dear Julian

I'm afraid that it's not possible to interface with PicoLog in this way. I think your best option would be to write your own software.

The bullet point in the manual that you mention is referring to the ability of PicoLog to allow you to analyse saved data whilst collecting new data.

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