Redboard Turbo SerialUSB is slooooow.
I am developing a stepper motor speed control library with a Serial menu driven interface example sketch.
The stepper motor update needs to be called at least once per 1mS to get 1000 steps per sec speed.
On the UNO/Mega I can get down to <1mS latency by adding more calls to stepper.run() around the various menu print statements.
(The Serial output is buffered via pfodBufferedStream (https://www.forward.com.au/pfod/pfodPar … index.html) so that it does not block)
Then on moving to the Redboard Turbo with the same sketch, replacing Serial with SerialUSB, the latency jumped to 10mS.
10 times slower and unusable.
The fix is to NOT use SerialUSB, but instead use a hardware serial I/O, Serial1, to communicate with the Redboard Turbo.
Using a 3v3 USB to Serial cable e.g. Sparkfun USB to TTL Serial Cable connected to RXD to D0 and TXD to D1,
and re-running gave latencies of 310uS
p.s. programming the Redboard Turbo is problematic.
If it fails to program, first I press the reset pushbutton once, reselect the COM port in Arduino Tools menu and retry.
If that does not work I double press the reset push button and try again.
So far that process has worked.