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It doesn't matter whether you are using a small LDR in a simple circuit to detect the changing light or whether you are using a more elaborate sensor such as a Thermal Conductivity Detector as part of a Wheatstone Bridge for Gas Chromatography analysis. ... the procedure is basically the same in all areas of science: We need to acquire the data from the sensor circuit so that we can review it at leisure anytime and so analyse the data information in a structured way. Here on EC it is great to structure circuits, but there is currently no provision to capture any of its data nor to import/export external real data.
Here I am putting forward a reminder that your board circuit can be output to a simple free data acquisition program so that you can analyse your data output at leisure and re-introduce it to your oscilloscope/spreadsheet graph whenever you wish, having performed any suitable alterations to it such as removing wild outliers or having smoothed the data with a moving average etc. Measuring frequency alterations and finding Mean and error estimation is far better done that way rather than guessing wildly on the fly whilst watching a one run through on an oscilloscope.
Here then are some potential strings to your bow, just as I am learning a lot of things from reading your circuit knowledge.
1: SoundcardScope ......... a free oscilloscope to download on to your computer ......loads of buttons and knobs on it to set the threshold, alter LPF, HPF and bandpass etc as well as a FFT to view frequency vs magnitude.....great for learning about using an oscilloscope but it won't handle MHz frequencies....A capacitor/ high resistor will suffice as a probe from your circuit to the mic jack on your computer for a simple starter, albeit with a noisy signal...do a little Google research on oscilloscope probe first though....don't want to ruin a sound card!
2: Audacity..........a sound analysis free download program with great possibilities for other frequency usage Inc FFT and raw data in/out. It is not MATLAB or the SPSS which I used to use, but it it is handy all the same.
3: CoolTerm .......a must have free data acquisition program for your computer.....stream your live data straight to there from your circuit output ( best via an Arduino ....USB). once the data is there, it is yours forever to copy/paste in to Excel or other free spreadsheet such as OpenOffice or LibreOffice etc. You can then analyse it and present it as a graph for any standard PC user whenever you wish, either for hobby or professional presentation.(you can perform most general/statistical maths operations in Excel).
So there it is....an introduction to your very real data acquisition from your board circuits.....I may do more articles on structured analysis of acquired data if there is enough interest, but for now here you can capture a mass of live data streamed from your circuit in to one little text file etc which is much smaller than a normal photo snapshot file size.
As a first example you could stream the sound (eg guitar string) from a mic/ amplifier in to a CoolTerm file then paste that data in to Excel and see it as a graph there like an oscilloscope snapshot to deduce its fundamental frequency and to perform an FFT to see which other harmonics are involved.....you could then make a low pass/notch filter etc directed at one of those bad frequencies and take it out using Audacity so that you end up with a better playback presentation. You will come up with your own ideas once you are familiar with capturing data from your own circuits.....Example 2....How about capturing streamed data from different coloured LEDs as they pass through a certain fixed liquid...Analyse the data at leisure then create an LED circuit which comes on only if a green light frequency is passing through the liquid.....thoughts of 'spectrophotometry' there?
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