Add input_modes.md

docs/commands.md

@@ -60,6 +60,21 @@ Possible values are:
 * `CTRL_MODE_CURRENT_CONTROL`
 * `CTRL_MODE_VOLTAGE_CONTROL` - this one is not normally used.
 
+### Input Mode
+The default input mode is `INPUT_MODE_PASSTHROUGH`.
+Modes can be selected by changing `<axis>.controller.config.input_mode`.
+Possible values are:
+* `INPUT_MODE_INACTIVE`
+* `INPUT_MODE_PASSTHROUGH`
+* `INPUT_MODE_VEL_RAMP`
+* `INPUT_MODE_POS_FILTER`
+* `INPUT_MODE_MIX_CHANNELS`
+* `INPUT_MODE_TRAP_TRAJ`
+* `INPUT_MODE_CURRENT_RAMP`
+* `INPUT_MODE_MIRROR`
+
+For more information, see [input_modes](input_modes.md).
+
 # Control Commands
 * `<axis>.controller.input_pos = <encoder_counts>`
 * `<axis>.controller.input_vel = <encoder_counts/s>`

docs/input_modes.md

@@ -0,0 +1,106 @@
+# Input Modes
+As of version ###, ODrive now intercepts the incoming commands and can apply filters to them.  The old protocol values `pos_setpoint`, `vel_setpoint`, and `current_setpoint` are still used internally by the closed-loop cascade control, but the user cannot write to them directly.  This allows us to condense the number of ways the ODrive accepts motion commands.  The new commands are:
+
+* `<axis>.controller.config.input_mode`
+* `<axis>.controller.input_pos`
+* `<axis>.controller.input_vel`
+* `<axis>.controller.input_current`
+
+The Input Modes currently valid are:
+* `INPUT_MODE_INACTIVE`
+* `INPUT_MODE_PASSTHROUGH`
+* `INPUT_MODE_VEL_RAMP`
+* `INPUT_MODE_POS_FILTER`
+* `INPUT_MODE_MIX_CHANNELS`
+* `INPUT_MODE_TRAP_TRAJ`
+* `INPUT_MODE_CURRENT_RAMP`
+* `INPUT_MODE_MIRROR`
+
+---
+
+## INPUT_MODE_INACTIVE
+Disable inputs.  Setpoints retain their last value.
+
+## INPUT_MODE_PASSTHROUGH
+Pass `input_xxx` through to `xxx_setpoint` directly.
+
+### Valid Inputs:
+* `input_pos`
+* `input_vel`
+* `input_current`
+
+### Valid Control modes:
+* `CTRL_MODE_VOLTAGE_CONTROL`
+* `CTRL_MODE_CURRENT_CONTROL`
+* `CTRL_MODE_VELOCITY_CONTROL`
+* `CTRL_MODE_POSITION_CONTROL`
+
+## INPUT_MODE_VEL_RAMP
+Ramps a velocity command from the current value to the target value.
+
+### Configuration Values:
+* `<axis>.controller.config.vel_ramp_rate` [cpr/sec]
+* `<axis>.controller.config.inertia` [A/(count/s^2))]
+
+### Valid inputs:
+* `input_vel`
+
+### Valid Control Modes:
+* `CTRL_MODE_VELOCITY_CONTROL`
+
+## INPUT_MODE_POS_FILTER
+Implements a 2nd order position tracking filter.  Inteded for use with step/dir interface, but can also be used with position-only commands.
+
+### Configuration Values:
+* `<axis>.controller.config.input_filter_bandwidth`
+* `<axis>.controller.config.inertia`
+
+### Valid inputs:
+* `input_pos`
+
+### Valid Control modes:
+* `CTRL_MODE_POSITION_CONTROL`
+
+## INPUT_MODE_MIX_CHANNELS
+Not Implemented.
+
+
+## INPUT_MODE_TRAP_TRAJ
+Implementes an online trapezoidal trajectory planner.
+
+### Configuration Values:
+* `<axis>.trap_traj.config.vel_limit`
+* `<axis>.trap_traj.config.accel_limit`
+* `<axis>.trap_traj.config.decel_limit`
+* `<axis>.controller.config.inertia`
+
+### Valid Inputs:
+* `input_pos`
+
+### Valid Control Modes:
+* `CTRL_MODE_POSITION_CONTROL`
+
+## INPUT_MODE_CURRENT_RAMP
+Ramp a current command from the current value to the target value.
+
+### Configuration Values:
+* `<axis>.controller.config.current_ramp_rate`
+
+### Valid Inputs:
+* `input_current`
+
+### Valid Control Modes:
+* `CTRL_MODE_CURRENT_CONTROL`
+
+## INPUT_MODE_MIRROR
+Implements "electronic mirroring".  This is like electronic camming, but you can only mirror exactly the movements of the other motor, according to a fixed ratio
+
+### Configuration Values
+* `<axis>.controller.config.axis_to_mirror`
+* `<axis>.controller.config.mirror_ratio`
+
+### Valid Inputs
+* None.  Inputs are taken directly from the other axis encoder estimates
+
+### Valid Control modes
+* `CTRL_MODE_POSITION_CONTROL`