diff --git a/control/app/picadae_api.py b/control/app/picadae_api.py
index 1ee2c89..e6620dd 100644
--- a/control/app/picadae_api.py
+++ b/control/app/picadae_api.py
@@ -275,6 +275,12 @@ class Picadae:
         time.sleep( dur_ms / 1000.0 )
         return self.note_off(midi_pitch)
 
+    def make_seq( self, midi_pitch, base_atk_us, dur_ms, delta_us, note_cnt ):
+        for i in range(note_cnt):
+            self.make_note( midi_pitch, base_atk_us + i*delta_us, dur_ms )
+            time.sleep( dur_ms / 1000.0 )
+        return Result()
+
     def set_log_level( self, log_level ):
         self.log_level = log_level
         return Result()
@@ -286,13 +292,17 @@ class Picadae:
         return vel
 
     def _usec_to_coarse_and_fine( self, usec ):
+
+        coarse_usec = self.prescaler_usec*255 # usec's in one coarse tick
         
-        coarse = int( usec / (self.prescaler_usec*255))
-        fine   = int((usec - coarse*self.prescaler_usec*255) / self.prescaler_usec)
+        coarse = int( usec / coarse_usec )
+        fine   = int((usec - coarse*coarse_usec) / self.prescaler_usec)
 
         assert( coarse <= 255 )
         assert( fine <= 255)
 
+        print("C:%i F:%i : %i " % (coarse,fine, coarse*coarse_usec + fine*self.prescaler_usec ))
+
         return coarse,fine
 
     def _send( self, opcode, i2c_addr, reg_addr, byteL  ):
diff --git a/control/app/picadae_shell.py b/control/app/picadae_shell.py
index ae7c655..1ea4ebc 100644
--- a/control/app/picadae_shell.py
+++ b/control/app/picadae_shell.py
@@ -21,7 +21,8 @@ class PicadaeShell:
             'f':{ "func":"get_pwm_freq", "minN":1,  "maxN":1, "help":"freq <pitch>"},
             'i':{ "func":"get_pwm_div",  "minN":1,  "maxN":1, "help":"div <pitch>"},
             'W':{ "func":"write_table",  "minN":1,  "maxN":1, "help":"write_table <pitch>"},
-            'N':{ "func":"make_note",    "minN":3,  "maxN":3, "help":"note <pitch> atkUs durMs"},
+            'N':{ "func":"make_note",    "minN":3,  "maxN":3, "help":"note <pitch> <atkUs> <durMs>"},
+            'S':{ "func":"make_seq",     "minN":5,  "maxN":5, "help":"seq  <pitch> <atkUs> <durMs> <deltaUs> <note_count>"}, 
             'L':{ "func":"set_log_level","minN":1,  "maxN":1, "help":"log <level> (0-1)."}
             }