Hi, I'm working with a group under Professor Tegmark at MIT. We've been messing around with the roach as a spectrometer (tutorial 3) and we're trying to get the unit conversion from the strange power-like units the roach spits out to dBm. I looked at the datasheet for the ADC, and it seems like the ADC accepts inputs from [-1, 1] V and digitizes them. We then retrieve this data off the roach, and it seems like it's scaled, but we can't figure how.
Also, the input voltage at which the ADC clips seems to depend on input frequency, as seen in the attached plot. To make it, for each frequency, we ramped up the power of the input sinusoid until the ADC clipped. I guess there might be some resonances where the input voltage is low?
clipping.pdf
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