@AdolficusGC@GoGeocaching@arduino Cool. To solve my cache people have to build a little decoder from a kit in an earlier part of the cache, then they decode IR Morse signals in the field.
@Atrix256 Write the quadratic as the sum of a linear function which goes through the two given points (say x = a and b) and another quadratic. This second quadratic goes through (a,0) and (b,0) and so has zero gradient at x = (a+b) / 2.
@sigfpe I think I would try saying either ‘well this line is pretty good, and so is this one, but these other ones are bad’, or ‘pick a line, any line, and I will tell you how good it is’.
@drfootleg Is the stuff https://t.co/KIfJREvZFl make what you’re looking for ? I played with one ages ago and it seemed ok for digital signals. Mine didn’t have any analogue inputs, so no help with signal integrity issues.