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Servo

Send a Servo config message to configure a pin a servo. Then use the SET_PIN_MODE message to attach/detach Servo support to a pin. This saves space in the protocol by reusing the SET_PIN_MODE message, but the host software implementation could have a different interface, e.g. Arduino's attach() and detach().

The SERVO_CONFIG message can be sent at any time to chang the settings.

Added in Firmata protocol version 2.1.0.

Servo config

// minPulse and maxPulse are 14-bit unsigned integers
0  START_SYSEX          (0xF0)
1  SERVO_CONFIG         (0x70)
2  pin number           (0-127)
3  minPulse LSB         (0-6)
4  minPulse MSB         (7-13)
5  maxPulse LSB         (0-6)
6  maxPulse MSB         (7-13)
7  END_SYSEX            (0xF7)

This is just the standard SET_PIN_MODE message: Set digital pin mode

0  set digital pin mode (0xF4) (MIDI Undefined)
1  pin number           (0-127)
2  state                (SERVO, 4)

Write to servo, servo write is performed if the pin mode is SERVO

0  ANALOG_MESSAGE       (0xE0-0xEF)
1  value LSB
2  value MSB

If the pin number is higher than 15, or if the value to write to the servo is greater than 14 bits, then the Extended Analog message can be used in place of the standard ANALOG_MESSAGE:

0  START_SYSEX              (0xF0)
1  extended analog message  (0x6F)
2  pin                      (0-127)
3  bits 0-6                 (least significant byte)
4  bits 7-13                (most significant byte)
... additionaly bytes may be sent if more bits are needed
N  END_SYSEX                (0xF7)