Take physical distance measurements, assess sonar accuracy, calibrate code accordingly

[kreaturen]

Sonar has an offset of only +/- 1 (+/-2) depending on range. Doesn't need calibration when running arduino code.

Tested it from 10 - 210 cm:

Average: 9cm -1 Average: 9cm -1 Average: 9cm -1

Average: 19cm -1 Average: 19cm -1 Average: 19cm -1

Average: 29cm -1 Average: 29cm -1 Average: 28cm -2

Average: 38cm -2 Average: 38cm -2 Average: 38cm -2

Average: 49cm -1 Average: 49cm -1 Average: 49cm -1

Average: 59cm -1 Average: 59cm -1 Average: 59cm -1

Average: 69cm -1 Average: 69cm -1 Average: 69cm -1

Average: 81cm +1 Average: 81cm +1 Average: 81cm +1

Average: 91cm +1 Average: 91cm +1 Average: 90cm 0

Average: 100cm 0 Average: 100cm 0 Average: 100cm 0

Average: 110cm 0 Average: 110cm 0 Average: 110cm 0

Average: 120cm 0 Average: 120cm 0 Average: 120cm 0

Average: 130cm 0 Average: 130cm 0 Average: 130cm 0

Average: 140cm 0 Average: 140cm 0 Average: 140cm 0

Average: 151cm +1 Average: 151cm +1 Average: 151cm +1

Average: 161cm +1 Average: 161cm +1 Average: 161cm +1

Average: 171cm +1 Average: 171cm +1 Average: 171cm +1

Average: 181cm +1 Average: 181cm +1 Average: 181cm +1

Average: 191cm +1 Average: 191cm +1 Average: 191cm +1

Average: 201cm +1 Average: 201cm +1 Average: 201cm +1

Average: 212cm +2 Average: 212cm +2 Average: 212cm +2