Hello
Let's say I want to measure the output voltage vs the input voltage of a device (see blackbox.PNG).
Also we know that ideally we can caractherize the device behavior with a real-valued function of a real variable.
(in other words we're watching
x and
f(x) voltages as if we were watching real numbers)
So we can have
f(x)=log(x) or
f(x)=x^2 or
f(x)=5*x and so on...
Also we know that the device isn't really perfect at the moment and we need to trim some potentiometers on the device to match (to approximate) perfectly this function.
What is the best method to achieve that?
I mean i can see for example the function with a 2-channel scope in XY mode and it's ok but i can't got really the numbers...
(maybe it's only me with a Rigol DS1052E but yeah I can store the csv data but I have to plug and unplug the USB stick every time I change something...NO!)
We can try to acquire data with an arduino but we can't read two input simultaneusly (1 ADC only, I've seen that the Portenta H7 have two but don't know more on that)
Another idea, the simplest to me but possibly can be the worst is to take one ADC to read the input
x0 then the digital value sets an EEPROM in order to output from a DAC the desired voltage that is
f(x0)(those digital values were previously written to the EEPROM but we don't care about that)
Then this voltage is compared with the one caming from the output of the device (the blackbox) using an opamp (maybe you can approach different techniques at this point, don't matter)
Finally we read the difference in some way using an arduino or simply the scope.
I don't know, I have searched for DAQs online but seems a bit too expensive option to me, the ones that can read more input simultaneously starts from 1900 euros!
Also would be ideal to connect this acquiring process to scilab or others free numeric computing environment but maybe I'm asking too much for a cheap thing.
Please advise me! I'm sure that there is a better option but I can't figure it out, please let me sleep tonight
Cheers