I want to check Batteries of various chemical compositions for their discharge characteristics.
Usually, their capacity is rated at discharging with a fraction of their capacity, like 0.2*C,
so for a 1 Ah battery, the discharge current would be 0.2*1Ah=200mA, which would discharge that battery in 5 hours.
I have a lot of high-power resistors, so setting up a current sink would not be a problem.
I want to do this data recording on a linux computer, I was thinking of a complex setup with a multimeter measuring that current, a webcam capturing the display, imagemagick to cut away everything but the LCD of that multimeter, and tesseract(a free OCR software) to OCR and append the timestamp and value to a textfile. All that would run at fixed time intervals (say a minute) via a cron or python script.
But I do have a Rigol 1102Z-E scope, how would I query the momentary input voltage via SCPI?
Is there a "Triggerless" mode to do this without having a trigger event?
That would make things a lot easier...
Or how do You guys do this?