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Adding support for brushless/brushed ESC controlled motor

This release added support for brushless ESC, including brushed ESC and brushless ESC, hobby RC car ESC and drone ESC. The current ESC control signal is 244HZ, should be supported by most of the brushless drone ESC and brushless car ESC. Unfortunately many Brushed ESC do not support this high frequency, they only support 60HZ, so changing config.h file is necessary. the PWM pin is arduino Pin11, the motor PWM pin, if using the red CNC shield, it's the "Z Stop" pin.
Added new system setting $38 for ESC type, default is 0. Just like changing any other setting, in serial interface, run $38= to set it:

$38=0, to disable esc, using regular motor, as usual.
$38=1, to use drone brushless ESC, meaning ESC control signal on time starts from 1ms. This also support brushed ESC, but currently I am using 244HZ for the ESC control signal, which is most likely too high for traditional brushed ESC. in that case you can modify the config file to use 60HZ setting.
$38=2, to use RC hobby CAR brushless ESC, meaning ESC control signal on time starts from 1.5ms. (<1.5ms is for brake and reverse)

Support ESC initialization (as a safety feature of the ESC, it must accept a sane signal first to start working properly.
Support ESC soft start, "slowly" ramp up motor speed, this can prevent ESC from locking down ( it's also a ESC safety feature, it doesn't allow power output from 0 and suddenly jump to max).
Support ESC soft stop, "slowly" slow down motor speed, this can prevent ESC from sudden brake when running at high speed, which has a big impact to the system. Suggest change the ESC firmware setting to disable the brake function to prevent ESC suddenly brake from 10000RPM to 0RPM.

uncomment this line: //#define ESC_PWM_FREQ_60HZ 60
comment out this line: #define ESC_PWM_FREQ_244HZ 244
However due to the slow frequency (60HZ) and longer period (1000ms/60=16.67ms) of the cycle , only a very small range of duty cycle from 1.5ms to 2.0ms is valid for the ESC in a long period of 16.6ms, so we don't have much of power level in this case, only 9.

ESC signal cable has 3wires, signal, 5V, GND and two power wires.

Connect ESC signal wire to the Arduino Pin11 or the famous little red CNC shield (which works with Arduino Uno) Z stop pin.
5V : Ignore 5V (red or not available)
Gnd : connect arduino Gnd.
ESC power cable RED + and BLACK -, connect 7V to 12V+ high current power supply according to ESC's spec.

wire connection

can use BCNC or Arduino IDE Serial monitor or any serial tool:

run command
run $30=10000 to set max RPM to 10000 or according to your motor's spec.
run $38=1 to enable drone esc if you are using one
run M3 S1000 to start with a small RPM, assuming 1000RPM, motor should start working now.
run M3 S2000 to speed up, motor should speed up now
run M3 S10000 to let motor run at max power.
run M3 S8000 to let motor slow down a little bit.
run M3 s0 to stop the motor (if you have already disabled the ESC brake)* * *
run M3 s300 to slow down the motor first if you have not already disabled the ESC brake and you don't like motor hard brake.
run M3 s0 or M5 to stop the motor completely.

Check out more on the Ant PCB CNC :