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@Gordon
Yes, so what happens is normally the 0-3.3v voltage is converted to a number between 0 and 1 (eg via
analogRead). Actually it's the CPU's voltage, which is supposed to be 3.3v, but may not be if you're powering it externally or drawing lots of power. You can check withE.getAnalogVRef().For the waveform, the numbers are integers, so can't be fractional. For 8 bits you have a number that can be between 0 and 255 (
2^8 - 1), and for 16 you have one between 0 and 65535 (2^16 - 1). Waveform just multiplies the reading up to that range.So for instance if you wanted to work out what 49408 was, you'd do
49408 * 3.3 / 65536 = 2.48. It's not the voltage you had measured, but I think that might be something to do with the way you're measuring (wrong pin?) as the numbers you have posted above don't look quite right.