pybricks · laurensvalk · Sep 11, 2025 · Sep 1, 2025 · Sep 1, 2025 · Sep 1, 2025
diff --git a/lib/pbio/drv/usb/usb_stm32.c b/lib/pbio/drv/usb/usb_stm32.c
@@ -36,7 +36,7 @@ PROCESS(pbdrv_usb_process, "USB");
 // to/from FIFOs in 32-bit chunks.
 static uint8_t usb_in_buf[USBD_PYBRICKS_MAX_PACKET_SIZE] __aligned(4);
 static uint8_t usb_response_buf[PBIO_PYBRICKS_USB_MESSAGE_SIZE(sizeof(uint32_t))] __aligned(4);
-static uint8_t usb_status_buf[PBIO_PYBRICKS_USB_MESSAGE_SIZE(PBSYS_STATUS_REPORT_SIZE)] __aligned(4);
+static uint8_t usb_status_buf[PBIO_PYBRICKS_USB_MESSAGE_SIZE(PBIO_PYBRICKS_EVENT_STATUS_REPORT_SIZE)] __aligned(4);
 static uint8_t usb_stdout_buf[USBD_PYBRICKS_MAX_PACKET_SIZE] __aligned(4);
 static volatile uint32_t usb_in_sz;
 static volatile uint32_t usb_response_sz;

diff --git a/lib/pbio/include/pbio/light.h b/lib/pbio/include/pbio/light.h
@@ -38,6 +38,7 @@ pbio_error_t pbio_color_light_on_hsv(pbio_color_light_t *light, const pbio_color
 pbio_error_t pbio_color_light_on(pbio_color_light_t *light, pbio_color_t color);
 pbio_error_t pbio_color_light_off(pbio_color_light_t *light);
 void pbio_color_light_start_blink_animation(pbio_color_light_t *light, const pbio_color_hsv_t *hsv, const uint16_t *cells);
+void pbio_color_light_start_breathe_animation(pbio_color_light_t *light, uint16_t hue);
 void pbio_color_light_start_animation(pbio_color_light_t *light, uint16_t interval, const pbio_color_compressed_hsv_t *cells);
 
 #else // PBIO_CONFIG_LIGHT
@@ -57,6 +58,9 @@ static inline pbio_error_t pbio_color_light_off(pbio_color_light_t *light) {
 static inline void pbio_color_light_start_blink_animation(pbio_color_light_t *light, const pbio_color_hsv_t *hsv, const uint16_t *cells) {
 }
 
+static inline void pbio_color_light_start_breathe_animation(pbio_color_light_t *light, uint16_t hue) {
+}
+
 static inline void pbio_color_light_start_animation(pbio_color_light_t *light, uint16_t interval, const pbio_color_compressed_hsv_t *cells) {
 }
 

diff --git a/lib/pbio/include/pbio/protocol.h b/lib/pbio/include/pbio/protocol.h
@@ -235,7 +235,7 @@ typedef enum {
      * Status report event.
      *
      * The payload is one 32-bit little-endian unsigned integer containing
-     * ::pbio_pybricks_status_t flags and a one byte program identifier
+     * ::pbio_pybricks_status_flags_t flags and a one byte program identifier
      * representing the currently active program if it is running.
      *
      * @since Pybricks Profile v1.0.0. Program identifier added in Pybricks Profile v1.4.0.
@@ -331,12 +331,12 @@ typedef enum {
     PBIO_PYBRICKS_STATUS_BLE_HOST_CONNECTED = 9,
     /** Total number of indications. */
     NUM_PBIO_PYBRICKS_STATUS,
-} pbio_pybricks_status_t;
+} pbio_pybricks_status_flags_t;
 
 /**
  * Converts a status value to a bit flag.
  *
- * @param [in]  status  A ::pbio_pybricks_status_t value.
+ * @param [in]  status  A ::pbio_pybricks_status_flags_t value.
  * @return              A bit flag corresponding to @p status.
  */
 #define PBIO_PYBRICKS_STATUS_FLAG(status) (1 << status)

diff --git a/lib/pbio/include/pbsys/status.h b/lib/pbio/include/pbsys/status.h
@@ -14,25 +14,15 @@
 
 #include <pbio/protocol.h>
 
-#define PBSYS_STATUS_REPORT_SIZE 7
-
-/**
- * Status flag change.
- */
-typedef enum {
-    /** System status indicator was set. */
-    PBSYS_STATUS_CHANGE_SET,
-    /** System status indicator was cleared. */
-    PBSYS_STATUS_CHANGE_CLEARED,
-} pbsys_status_change_t;
-
 void pbsys_status_set_program_id(pbio_pybricks_user_program_id_t program_id);
-void pbsys_status_set(pbio_pybricks_status_t status);
-void pbsys_status_clear(pbio_pybricks_status_t status);
-bool pbsys_status_test(pbio_pybricks_status_t status);
-bool pbsys_status_test_debounce(pbio_pybricks_status_t status, bool state, uint32_t ms);
+void pbsys_status_set(pbio_pybricks_status_flags_t status);
+void pbsys_status_clear(pbio_pybricks_status_flags_t status);
+bool pbsys_status_test(pbio_pybricks_status_flags_t status);
+bool pbsys_status_test_debounce(pbio_pybricks_status_flags_t status, bool state, uint32_t ms);
 uint32_t pbsys_status_get_flags(void);
 uint32_t pbsys_status_get_status_report(uint8_t *buf);
+void pbsys_status_increment_selected_slot(bool increment);
+pbio_pybricks_user_program_id_t pbsys_status_get_selected_slot(void);
 
 #endif // _PBSYS_STATUS_H_
 

diff --git a/lib/pbio/src/light/color_light.c b/lib/pbio/src/light/color_light.c
@@ -140,6 +140,41 @@ void pbio_color_light_start_blink_animation(pbio_color_light_t *light, const pbi
     pbio_light_animation_start(&light->animation);
 }
 
+static uint8_t breathe_animation_progress;
+static uint16_t breathe_animation_hue;
+
+static uint32_t pbio_color_light_breathe_next(pbio_light_animation_t *animation) {
+
+    pbio_color_light_t *light = PBIO_CONTAINER_OF(animation, pbio_color_light_t, animation);
+
+    // The brightness pattern has the form /\ through which we cycle in N steps.
+    // It is reset back to the start when the user program starts.
+    const uint8_t animation_progress_max = 200;
+
+    pbio_color_hsv_t hsv = {
+        .h = breathe_animation_hue,
+        .s = 100,
+        .v = breathe_animation_progress < animation_progress_max / 2 ?
+            breathe_animation_progress :
+            animation_progress_max - breathe_animation_progress,
+    };
+
+    light->funcs->set_hsv(light, &hsv);
+
+    // This increment controls the speed of the pattern and wraps on completion
+    breathe_animation_progress = (breathe_animation_progress + 4) % animation_progress_max;
+
+    return 40;
+}
+
+void pbio_color_light_start_breathe_animation(pbio_color_light_t *light, uint16_t hue) {
+    pbio_color_light_stop_animation(light);
+    breathe_animation_progress = 0;
+    breathe_animation_hue = hue;
+    pbio_light_animation_init(&light->animation, pbio_color_light_breathe_next);
+    pbio_light_animation_start(&light->animation);
+}
+
 static uint32_t pbio_color_light_animate_next(pbio_light_animation_t *animation) {
     pbio_color_light_t *light = PBIO_CONTAINER_OF(animation, pbio_color_light_t, animation);
 

diff --git a/lib/pbio/sys/bluetooth.c b/lib/pbio/sys/bluetooth.c
@@ -198,7 +198,7 @@ static PT_THREAD(pbsys_bluetooth_monitor_status(struct pt *pt)) {
         // wait for status to change or timeout
         PT_WAIT_UNTIL(pt, pbsys_status_get_flags() != old_status_flags ||
             #if PBSYS_CONFIG_HMI_NUM_SLOTS
-            pbsys_hmi_get_selected_program_slot() != old_program_slot ||
+            pbsys_status_get_selected_slot() != old_program_slot ||
             #endif
             etimer_expired(&timer));
 

diff --git a/lib/pbio/sys/command.c b/lib/pbio/sys/command.c
@@ -49,7 +49,7 @@ pbio_pybricks_error_t pbsys_command(const uint8_t *data, uint32_t size) {
             }
             // Use payload as program ID, otherwise use active user slot.
             return pbio_pybricks_error_from_pbio_error(
-                pbsys_main_program_request_start((size == 2 ? data[1] : pbsys_hmi_get_selected_program_slot()), PBSYS_MAIN_PROGRAM_START_REQUEST_TYPE_REMOTE));
+                pbsys_main_program_request_start((size == 2 ? data[1] : pbsys_status_get_selected_slot()), PBSYS_MAIN_PROGRAM_START_REQUEST_TYPE_REMOTE));
         }
         #if PBSYS_CONFIG_FEATURE_BUILTIN_USER_PROGRAM_REPL
         case PBIO_PYBRICKS_COMMAND_START_REPL:

diff --git a/lib/pbio/sys/hmi.c b/lib/pbio/sys/hmi.c
@@ -37,29 +37,11 @@
 #define DEBUG_PRINT(...)
 #endif
 
-// The selected slot is not persistent across reboot, so that the first slot
-// is always active on boot. This allows consistently starting programs without
-// visibility of the display.
-static uint8_t selected_slot = 0;
-
-/**
- * Gets the currently selected program slot.
- *
- * @return The currently selected program slot (zero-indexed).
- */
-uint8_t pbsys_hmi_get_selected_program_slot(void) {
-    return selected_slot;
-}
-
 void pbsys_hmi_init(void) {
     pbsys_status_light_init();
     pbsys_hub_light_matrix_init();
 }
 
-void pbsys_hmi_handle_status_change(pbsys_status_change_t event, pbio_pybricks_status_t data) {
-    pbsys_status_light_handle_status_change(event, data);
-}
-
 /**
  * Polls the HMI.
  *
@@ -110,7 +92,7 @@ static pbio_error_t pbsys_hmi_launch_program_with_button(pbio_os_state_t *state)
 
         if (pressed & PBIO_BUTTON_CENTER) {
 
-            pbio_error_t err = pbsys_main_program_request_start(selected_slot, PBSYS_MAIN_PROGRAM_START_REQUEST_TYPE_HUB_UI);
+            pbio_error_t err = pbsys_main_program_request_start(pbsys_status_get_selected_slot(), PBSYS_MAIN_PROGRAM_START_REQUEST_TYPE_HUB_UI);
 
             if (err == PBIO_SUCCESS) {
                 // Program is available so we can leave this UI thread and
@@ -124,14 +106,14 @@ static pbio_error_t pbsys_hmi_launch_program_with_button(pbio_os_state_t *state)
         }
 
         // On right, increment slot when possible.
-        if ((pressed & PBIO_BUTTON_RIGHT) && selected_slot < 4) {
-            selected_slot++;
+        if (pressed & PBIO_BUTTON_RIGHT) {
+            pbsys_status_increment_selected_slot(true);
             pbsys_hub_light_matrix_update_program_slot();
         }
 
         // On left, decrement slot when possible.
-        if ((pressed & PBIO_BUTTON_LEFT) && selected_slot > 0) {
-            selected_slot--;
+        if (pressed & PBIO_BUTTON_LEFT) {
+            pbsys_status_increment_selected_slot(false);
             pbsys_hub_light_matrix_update_program_slot();
         }
     }

diff --git a/lib/pbio/sys/hmi.h b/lib/pbio/sys/hmi.h
@@ -8,9 +8,7 @@
 #include <pbsys/status.h>
 
 void pbsys_hmi_init(void);
-void pbsys_hmi_handle_status_change(pbsys_status_change_t event, pbio_pybricks_status_t data);
 void pbsys_hmi_poll(void);
 pbio_error_t pbsys_hmi_await_program_selection(void);
-uint8_t pbsys_hmi_get_selected_program_slot(void);
 
 #endif // _PBSYS_SYS_HMI_H_
diff --git a/lib/pbio/sys/light.c b/lib/pbio/sys/light.c
@@ -182,7 +182,7 @@ void pbsys_status_light_init(void) {
     #endif
 }
 
-static void pbsys_status_light_update_patterns(void) {
+void pbsys_status_light_handle_status_change(void) {
 
     // Warning pattern precedence.
     pbsys_status_light_indication_warning_t warning_indication = PBSYS_STATUS_LIGHT_INDICATION_WARNING_NONE;
@@ -222,46 +222,6 @@ static void pbsys_status_light_update_patterns(void) {
     }
 }
 
-#if PBSYS_CONFIG_STATUS_LIGHT_STATE_ANIMATIONS
-static uint8_t animation_progress;
-
-static uint32_t default_user_program_light_animation_next(pbio_light_animation_t *animation) {
-    // The brightness pattern has the form /\ through which we cycle in N steps.
-    // It is reset back to the start when the user program starts.
-    const uint8_t animation_progress_max = 200;
-
-    pbio_color_hsv_t hsv = {
-        .h = PBSYS_CONFIG_STATUS_LIGHT_STATE_ANIMATIONS_HUE,
-        .s = 100,
-        .v = animation_progress < animation_progress_max / 2 ?
-            animation_progress :
-            animation_progress_max - animation_progress,
-    };
-
-    pbsys_status_light_main->funcs->set_hsv(pbsys_status_light_main, &hsv);
-
-    // This increment controls the speed of the pattern and wraps on completion
-    animation_progress = (animation_progress + 4) % animation_progress_max;
-
-    return 40;
-}
-#endif // PBSYS_CONFIG_STATUS_LIGHT_STATE_ANIMATIONS
-
-void pbsys_status_light_handle_status_change(pbsys_status_change_t event, pbio_pybricks_status_t data) {
-    if (event == PBSYS_STATUS_CHANGE_SET || event == PBSYS_STATUS_CHANGE_CLEARED) {
-        pbsys_status_light_update_patterns();
-    }
-    if (event == PBSYS_STATUS_CHANGE_SET && (pbio_pybricks_status_t)(intptr_t)data == PBIO_PYBRICKS_STATUS_USER_PROGRAM_RUNNING) {
-        #if PBSYS_CONFIG_STATUS_LIGHT_STATE_ANIMATIONS
-        animation_progress = 0;
-        pbio_light_animation_init(&pbsys_status_light_main->animation, default_user_program_light_animation_next);
-        pbio_light_animation_start(&pbsys_status_light_main->animation);
-        #else
-        pbio_color_light_off(pbsys_status_light_main);
-        #endif // PBSYS_CONFIG_STATUS_LIGHT_STATE_ANIMATIONS
-    }
-}
-
 /**
  * Advances the light to the next state in the pattern.
  *

diff --git a/lib/pbio/sys/light.h b/lib/pbio/sys/light.h
@@ -11,11 +11,11 @@
 
 #if PBSYS_CONFIG_STATUS_LIGHT
 void pbsys_status_light_init(void);
-void pbsys_status_light_handle_status_change(pbsys_status_change_t event, pbio_pybricks_status_t data);
+void pbsys_status_light_handle_status_change(void);
 void pbsys_status_light_poll(void);
 #else
 #define pbsys_status_light_init()
-#define pbsys_status_light_handle_status_change(event, data)
+#define pbsys_status_light_handle_status_change()
 #define pbsys_status_light_poll()
 #endif
 

diff --git a/lib/pbio/sys/light_matrix.c b/lib/pbio/sys/light_matrix.c
@@ -68,7 +68,7 @@ static void pbsys_hub_light_matrix_show_idle_ui(uint8_t brightness) {
         for (uint8_t c = 0; c < pbsys_hub_light_matrix->size; c++) {
             bool is_on = r < 3 && c > 0 && c < 4;
             #if PBSYS_CONFIG_HMI_NUM_SLOTS
-            is_on |= (r == 4 && c == pbsys_hmi_get_selected_program_slot());
+            is_on |= (r == 4 && c == pbsys_status_get_selected_slot());
             #endif
             pbsys_hub_light_matrix_set_pixel(pbsys_hub_light_matrix, r, c, is_on ? brightness : 0);
         }
@@ -158,6 +158,13 @@ static uint32_t pbsys_hub_light_matrix_user_program_animation_next(pbio_light_an
  * @param start   @c true for start or @c false for stop.
  */
 void pbsys_hub_light_matrix_handle_user_program_start(bool start) {
+
+    #if PBSYS_CONFIG_HUB_LIGHT_MATRIX_DISPLAY
+    pbio_image_fill(pbdrv_display_get_image(), 0);
+    pbdrv_display_update();
+    return;
+    #endif
+
     if (start) {
         // The user animation updates only a subset of pixels to save time,
         // so the rest must be cleared before it starts.

diff --git a/lib/pbio/sys/main.c b/lib/pbio/sys/main.c
@@ -23,6 +23,7 @@
 #include "program_stop.h"
 #include "storage.h"
 #include <pbsys/program_stop.h>
+#include <pbsys/light.h>
 #include <pbsys/host.h>
 
 // Singleton with information about the currently (or soon) active program.
@@ -103,6 +104,14 @@ int main(int argc, char **argv) {
         pbsys_host_stdin_set_callback(pbsys_main_stdin_event);
         pbsys_hub_light_matrix_handle_user_program_start(true);
 
+        #if PBSYS_CONFIG_STATUS_LIGHT
+        #if PBSYS_CONFIG_STATUS_LIGHT_STATE_ANIMATIONS
+        pbio_color_light_start_breathe_animation(pbsys_status_light_main, PBSYS_CONFIG_STATUS_LIGHT_STATE_ANIMATIONS_HUE);
+        #else
+        pbio_color_light_off(pbsys_status_light_main);
+        #endif
+        #endif
+
         // Handle pending events triggered by the status change, such as
         // starting status light animation.
         while (pbio_os_run_processes_once()) {