Lecture notes:
Video 1.
How the 2D FFT works by Mike X Cohen (2017)
Source. Animations showing how the 2D Fourier transform looks like for simple inpuf functions.
Marco Reps by Ciro Santilli 37 Updated 2025-07-16
This mostly faceless German dude is awesome!
Jump wire by Ciro Santilli 37 Updated 2025-07-16
Notably used to connect:
You can buy large sets of them in combitation of male/male, male/female, female/female. Male/male is perhaps the most important
Video 1.
Making Jumper Wires by PCBurn! (2018)
Source.
Only certain battery voltages exist, because this voltage depends intrinsically on the battery's chemical composition.
learn.sparkfun.com/tutorials/battery-technologies/all (CC BY-SA) has a very good summary list, reordered from lowest to highest voltage:
Battery ShapeChemistryNominal VoltageRechargeable?
AA, AAA, C, D (Rechargeable)NiMH or NiCd1.2VYes
AA, AAA, C, and DAlkaline or Zinc-carbon1.5VNo
Coin CellLithium3VNo
Silver Flat PackLithium Polymer (LiPo)3.7VYes
9VAlkaline or Zinc-carbon9VNo
Car BatterySix-cell lead acid12.6VYes
Many/most microcontroller boards have analog-to-digital converters built into them, it is very convenient. E.g. it is the case for the Raspberry Pi Pico.

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