smartknob/proto/smartknob.proto

syntax = "proto3";

import "nanopb.proto";

package PB;

/*
 * Message FROM the SmartKnob to the host
 */
message FromSmartKnob {
    uint32 protocol_version = 1 [(nanopb).int_size = IS_8];
    oneof payload {
        Ack ack = 2;
        Log log = 3;
        SmartKnobState smartknob_state = 4;
    }
}

/*
 * Message TO the Smartknob from the host
 */
 message ToSmartknob {
    uint32 protocol_version = 1 [(nanopb).int_size = IS_8];
    uint32 nonce = 2;

    oneof payload {
        RequestState request_state = 3;
        SmartKnobConfig smartknob_config = 4;
    }
}

message Ack {
    uint32 nonce = 1;
}

message Log {
    string msg = 1 [(nanopb).max_length = 255];
}

message SmartKnobState {
    int32 current_position = 1;
    float sub_position_unit = 2;
    SmartKnobConfig config = 3;

    /** Value that changes each time the knob is pressed */
    uint32 press_nonce = 4 [(nanopb).int_size = IS_8];
}


message SmartKnobConfig {
    int32 position = 1;
    float sub_position_unit = 2;
    
    /**
     * Position is normally only applied when it changes, but sometimes it's desirable
     * to reset the position to the same value, so a nonce change can be used to force
     * the position values to be applied as well.
     *
     * NOTE: Must be < 256
     */
    uint32 position_nonce = 3 [(nanopb).int_size = IS_8];

    int32 min_position = 4;
    int32 max_position = 5;
    float position_width_radians = 6;
    float detent_strength_unit = 7;
    float endstop_strength_unit = 8;
    float snap_point = 9;
    string text = 10 [(nanopb).max_length = 50];
    repeated int32 detent_positions = 11 [(nanopb).max_count = 5];
    float snap_point_bias = 12;

    /**
     * Hue (0-255) for all 8 ring LEDs, if supported. Note: this will likely be replaced
     * with more configurability in a future protocol version.
     */
    int32 led_hue = 13 [(nanopb).int_size = IS_16];
}

message RequestState {}

message PersistentConfiguration {
    uint32 version = 1;
    MotorCalibration motor = 2;
    StrainCalibration strain = 3;
}

message MotorCalibration {
    bool calibrated = 1;
    float zero_electrical_offset = 2;
    bool direction_cw = 3;
    uint32 pole_pairs = 4;
}

message StrainCalibration {
    int32 idle_value = 1;
    int32 press_delta = 2; 
}