i2cproto.txt

I2C Protocol for Stepper controller:

	Command overview:

		Group 0: General parameters (FIRST BYTE is ALWAYS THE STEPPER INDEX THAT SHOULD BE MODIFIED)

			0x01		Get Acceleration & Deceleration (Allows to read 8 bytes; 2 IEEE floats in Little Endian; Acceleration first, then deceleration)
			0x02		Set Acceleration & Deceleration (Expects 8 bytes as 2 IEEE float's in Little Endian; Acceleration first, then deceleration)
			0x03		Get VMax (Allows to read 4 bytes as one IEEE float as VMax; Little Endian)
			0x04		Set VMax (Expects 4 bytes as IEEE float as VMax; Little Endian)
			0x05		Get alpha (step size in radians; 4 bytes for single IEEE float; Little endian)
			0x06		Set alpha (step size in radians; 4 bytes for single IEEE float; Little endian)
			0x07		Get Microstepping configuration; Normally shared
						Full steps		0
						1/2			1
						1/4			2
						1/8			3
						1/16			4
						1/32			5
						1/64 (unsup)		6
						1/128 (unsup)		7
			0x08		Set Microstepping configuration (see above); Normally SHARED!
			0x09		Set absolute position (4 byte IEEE single float; Little endian)
			0x0A		Get absolute position (4 byte IEEE single float; Little endian)
			...
			0x0E		Get FAULT bits (resets fault latch) - Returns a single bit with 1 bit per channel
					Bit 0 corresponds to channel 0, Bit 1 to channel 1, etc.
			0x0F		Execute recalculation of constants (after all parameters have been set)

		Group 1: Command queue

			0x10		Get available queue space (in entry numbers; max 255)

		Group 2: Queue operation

			0x20		Enqueue "sync point" on specified stepper (1 byte). Only if both steppers execute a
					synchronization point the command queue advances. Allows to synchronize stepper operation.
					Ex.: 0x20 0x00 or 0x20 0x01 for first or second stepper
			0x21		Enqueue move constant speed. Expects Stepper index and direction in first byte;
					(Bit 7 is direction; Bits 0-6 are stepper index) then 4 bytes IEEE float that specifies
					angular speed (rad / sec)
					Will never finish; Need group 3 or F to leave
			0x22		Move to (accelerated and decelerated; start and end stop)
					Expects 1 byte stepper index and direction (Bit 7 is direction; Bits 0-6 are stepper
					index) followed by 4 byte as one IEEE float that specifies the angular distance (radians)
					that should be covered
			0x23		Set constant speed with acceleration / deceleration; hold speed afterwards (no return)
					Will never finish; Need group 3 or F to leave
					Same as 0x21 but with acceleration ...
			0x24		Set position (absolute). This is - incontrast to 0x22 which is a relative start-to-stop
					movement - calculated relative to the current angular position. The coordinates are passed
					as angular position (radians)
			...
			0x2E		Hold position (normally not required; Eventually required after "Disable driver" has
					been used to re-enable the drivers; sufficient to execute on one for non-common control pins
			0x2F		Enqueue "Disable driver" - has to be executed on BOTH drivers if common pin output
					is used to be effective.

		Group 3: Execute operation abort previous ones

			0x3x		Same as above but discards ANY queued operation and executes the command immedately

		Group F: Emergency commands

			0xFE		Emergency stop (Stops all motors and KEEPS ENGAGED - motors will be "locked")
			0xFF		Emergency off (Stops all motors and DISABLED DRIVERS - motors will "free wheel")