add '#define SOFT_SERIAL_PIN D0' to keyboards/levinson/rev*/config.h

keyboards/levinson/rev1/config.h

@@ -41,6 +41,9 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 /* Set 0 if debouncing isn't needed */
 #define DEBOUNCING_DELAY 5
 
+/* serial.c configuration for split keyboard */
+#define SOFT_SERIAL_PIN D0
+
 /* Mechanical locking support. Use KC_LCAP, KC_LNUM or KC_LSCR instead in keymap */
 #define LOCKING_SUPPORT_ENABLE
 /* Locking resynchronize hack */

keyboards/levinson/rev2/config.h

@@ -41,6 +41,9 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 /* Set 0 if debouncing isn't needed */
 #define DEBOUNCING_DELAY 5
 
+/* serial.c configuration for split keyboard */
+#define SOFT_SERIAL_PIN D0
+
 /* Mechanical locking support. Use KC_LCAP, KC_LNUM or KC_LSCR instead in keymap */
 #define LOCKING_SUPPORT_ENABLE
 /* Locking resynchronize hack */

quantum/split_common/split-keyboards-list.txt

@@ -8,7 +8,7 @@ ok keyboards/handwired/qc60/rules.mk:SPLIT_KEYBOARD = yes
 ok keyboards/handwired/xealous/rules.mk:SPLIT_KEYBOARD = yes        # Use shared split_common code
 ok keyboards/iris/rules.mk:SPLIT_KEYBOARD = yes
 ok keyboards/lets_split_eh/rules.mk:SPLIT_KEYBOARD = yes
-keyboards/levinson/rules.mk:SPLIT_KEYBOARD = yes
+ok keyboards/levinson/rules.mk:SPLIT_KEYBOARD = yes
 keyboards/miniaxe/rules.mk:SPLIT_KEYBOARD = yes        # Use shared split_common code
 keyboards/nyquist/rules.mk:SPLIT_KEYBOARD = yes
 keyboards/quefrency/rules.mk:SPLIT_KEYBOARD = yes