feat: add calibration switch support

components/direction_controller/include/direction_controller.h

@@ -8,6 +8,7 @@
 
 #include <stdbool.h>
 #include <stddef.h>
+#include "driver/gpio.h"
 #include "esp_err.h"
 
 #ifdef __cplusplus
@@ -33,8 +34,25 @@ typedef struct {
     float initial_angle;                                /* Initial angle relative to South */
     int rotate_speed_us;                                /* Rotation speed (microseconds per step) */
     bool init_stepper_gpio;                             /* Initialize stepper GPIO in init */
+    const struct direction_controller_calibration_t *calibration; /* Optional calibration config */
 } direction_controller_config_t;
 
+/**
+ * @brief Calibration switch configuration
+ */
+typedef struct direction_controller_calibration_t {
+    bool enabled;                   /* Enable calibration */
+    gpio_num_t gpio_num;            /* Switch GPIO */
+    int active_level;               /* Active logic level (0 or 1) */
+    bool pullup_en;                 /* Enable internal pull-up (if supported) */
+    bool pulldown_en;               /* Enable internal pull-down (if supported) */
+    float calibration_angle;        /* Angle to set when switch is active */
+    float step_angle_deg;           /* Step angle per search iteration */
+    float max_sweep_deg;            /* Maximum total sweep angle */
+    bool search_cw;                 /* Search direction: true=clockwise, false=counterclockwise */
+    int settle_delay_ms;            /* Delay after each step to allow switch settle */
+} direction_controller_calibration_t;
+
 /**
  * @brief Parsed command types
  */
@@ -42,7 +60,8 @@ typedef enum {
     DIRECTION_CONTROLLER_CMD_UNKNOWN = 0,
     DIRECTION_CONTROLLER_CMD_HELP,
     DIRECTION_CONTROLLER_CMD_POSITION,
-    DIRECTION_CONTROLLER_CMD_DIRECTION
+    DIRECTION_CONTROLLER_CMD_DIRECTION,
+    DIRECTION_CONTROLLER_CMD_CALIBRATE
 } direction_controller_cmd_t;
 
 /**
@@ -86,6 +105,14 @@ esp_err_t direction_controller_rotate_to_angle(float target_angle);
  */
 esp_err_t direction_controller_rotate_to_direction(const char *input);
 
+/**
+ * @brief Calibrate direction using a switch
+ *
+ * @param config Optional calibration configuration, NULL uses config set in init
+ * @return ESP_OK on success
+ */
+esp_err_t direction_controller_calibrate(const direction_controller_calibration_t *config);
+
 /**
  * @brief Get current angle
  */
@@ -121,6 +148,16 @@ int direction_controller_get_rotate_speed_us(void);
  */
 void direction_controller_set_rotate_speed_us(int rotate_speed_us);
 
+/**
+ * @brief Set calibration configuration
+ */
+void direction_controller_set_calibration(const direction_controller_calibration_t *config);
+
+/**
+ * @brief Get calibration configuration (NULL if not configured)
+ */
+const direction_controller_calibration_t *direction_controller_get_calibration(void);
+
 #ifdef __cplusplus
 }
 #endif