Added validation and documentation that a device being configured for master mode must also enable the color camera

include/k4a/k4atypes.h

@@ -587,7 +587,9 @@ typedef enum
 {
     K4A_WIRED_SYNC_MODE_STANDALONE, /**< Neither 'Sync In' or 'Sync Out' connections are used. */
     K4A_WIRED_SYNC_MODE_MASTER,     /**< The 'Sync Out' jack is enabled and synchronization data it driven out the
-                                       connected wire.*/
+                                       connected wire. While in master mode the color camera must be enabled as part of the
+                                       multi device sync signalling logic. Even if the color image is not needed, the color
+                                       camera must be running.*/
     K4A_WIRED_SYNC_MODE_SUBORDINATE /**< The 'Sync In' jack is used for synchronization and 'Sync Out' is driven for the
                                        next device in the chain. 'Sync Out' is a mirror of 'Sync In' for this mode.
                                      */

src/sdk/k4a.c

@@ -570,6 +570,13 @@ static k4a_result_t validate_configuration(k4a_context_t *device, const k4a_devi
         if (K4A_SUCCEEDED(result) && config->wired_sync_mode == K4A_WIRED_SYNC_MODE_MASTER)
         {
             result = K4A_RESULT_FROM_BOOL(sync_out_cable_present == true);
+
+            if (K4A_SUCCEEDED(result) && config->color_resolution == K4A_COLOR_RESOLUTION_OFF)
+            {
+                LOG_ERROR("Device wired_sync_mode is set to K4A_WIRED_SYNC_MODE_MASTER, so color camera must be used "
+                          "on master device. Color_resolution can not be set to K4A_COLOR_RESOLUTION_OFF.");
+                return K4A_RESULT_FAILED;
+            }
         }
     }
 

tests/multidevice/multidevice.cpp

@@ -156,3 +156,72 @@ TEST_F(multidevice_ft, DISABLED_stream_two_2_then_1)
     k4a_device_close(m_device1);
     m_device1 = NULL;
 }
+
+TEST_F(multidevice_ft, DISABLED_ensure_color_camera_is_enabled)
+{
+    bool master_device_found = false;
+    bool subordinate_device_found = false;
+    uint32_t devices_present = k4a_device_get_installed_count();
+    ASSERT_LE((uint32_t)2, devices_present);
+
+    for (uint32_t x = 0; x < devices_present; x++)
+    {
+        ASSERT_EQ(K4A_RESULT_SUCCEEDED, k4a_device_open(x, &m_device1));
+
+        bool sync_in_cable_present;
+        bool sync_out_cable_present;
+
+        k4a_device_configuration_t config = K4A_DEVICE_CONFIG_INIT_DISABLE_ALL;
+
+        config.color_format = K4A_IMAGE_FORMAT_COLOR_MJPG;
+        config.color_resolution = K4A_COLOR_RESOLUTION_OFF;
+        config.depth_mode = K4A_DEPTH_MODE_NFOV_2X2BINNED;
+        config.camera_fps = K4A_FRAMES_PER_SECOND_30;
+
+        ASSERT_EQ(K4A_RESULT_SUCCEEDED,
+                  k4a_device_get_sync_jack(m_device1, &sync_in_cable_present, &sync_out_cable_present));
+
+        if (sync_out_cable_present)
+        {
+            // Negative test
+            config.wired_sync_mode = K4A_WIRED_SYNC_MODE_MASTER;
+            ASSERT_EQ(K4A_RESULT_FAILED, k4a_device_start_cameras(m_device1, &config));
+            k4a_device_stop_cameras(m_device1);
+
+            // Positive Test
+            config.wired_sync_mode = K4A_WIRED_SYNC_MODE_STANDALONE;
+            ASSERT_EQ(K4A_RESULT_SUCCEEDED, k4a_device_start_cameras(m_device1, &config));
+            k4a_device_stop_cameras(m_device1);
+
+            master_device_found = true;
+        }
+
+        if (sync_in_cable_present)
+        {
+            // Positive Test
+            config.wired_sync_mode = K4A_WIRED_SYNC_MODE_SUBORDINATE;
+            ASSERT_EQ(K4A_RESULT_SUCCEEDED, k4a_device_start_cameras(m_device1, &config));
+            k4a_device_stop_cameras(m_device1);
+
+            // Positive Test
+            config.wired_sync_mode = K4A_WIRED_SYNC_MODE_STANDALONE;
+            ASSERT_EQ(K4A_RESULT_SUCCEEDED, k4a_device_start_cameras(m_device1, &config));
+            k4a_device_stop_cameras(m_device1);
+
+            subordinate_device_found = true;
+        }
+
+        if (subordinate_device_found && sync_out_cable_present)
+        {
+            // Done with the test
+            break;
+        }
+
+        k4a_device_close(m_device1);
+        m_device1 = NULL;
+    }
+
+    // Make sure we found both devices.
+    ASSERT_EQ(master_device_found, true);
+    ASSERT_EQ(subordinate_device_found, true);
+}