Incorrect timing at slow RPMs with acceleration

[laurb9]

Describe the bug The test results in version 1.3.0 show the motor timing unexpectedly faster than the RPM indicates at 6 RPM, when LINEAR_SPEED mode is in use. At 60 RPM and above the timing works fine, up to the processor limit.

https://github.com/laurb9/StepperDriver/blob/master/examples/UnitTest/adafruit_feather_m0.txt#L43

BasicStepperDriver test, linear speed
  rpm=6000 expected=    365148µs elapsed=    343357µs step_err=   108µs avgstep=  1825µs
  rpm=600  expected=    365148µs elapsed=    343361µs step_err=   108µs avgstep=  1825µs
  rpm=60   expected=   1033246µs elapsed=   1010367µs step_err=   114µs avgstep=  5166µs
  rpm=6    expected=  10000000µs elapsed=   2457426µs step_err= 37712µs avgstep= 50000µs FAIL

To Reproduce Run sketch https://github.com/laurb9/StepperDriver/blob/master/examples/UnitTest Capture serial output. Nothing else needs to be attached to the board.

Platform Setup (please complete the following information):

• Arduino IDE version 1.8.3
• Board type Adafruit Feather M0 (Cortex M0)

[stale[bot]]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[stale[bot]]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[stale[bot]]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[stale[bot]]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.