Problem: Control a brushless ESC through Mach3

Idea: Program an Arduino microprocessor to convert mach3's PWM spindle output to a brushless ESC's 1-2ms input signal. A brushless ESC needs a 1-2ms on time every 20ms.

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Also have the Arduino ramp up from zero to the set speed in mach3.

Conundrum: I don't know how to program