diff --git a/2020-06_ucbus-stepper-melted/eagle.epf b/2020-06_ucbus-stepper-melted/eagle.epf
index ddffdca3d394345b2c9db9c8ab0c9dfaeaef67e6..c6124db219e541ad483c9ef381af95bc7b36e378 100644
--- a/2020-06_ucbus-stepper-melted/eagle.epf
+++ b/2020-06_ucbus-stepper-melted/eagle.epf
@@ -265,7 +265,6 @@ UsedLibraryUrn="urn:adsk.eagle:library:196"
 UsedLibraryUrn="urn:adsk.eagle:library:197"
 UsedLibraryUrn="urn:adsk.eagle:library:198"
 UsedLibraryUrn="urn:adsk.eagle:library:199"
-UsedLibrary="C:/Dropbox/CBA/circuits/eagle/parts/810-22-003-40-005191.lbr"
 UsedLibrary="C:/Dropbox/CBA/circuits/eagle/parts/comm.lbr"
 UsedLibrary="C:/Dropbox/CBA/circuits/eagle/parts/connector.lbr"
 UsedLibrary="C:/Dropbox/CBA/circuits/eagle/parts/dfet.lbr"
@@ -285,8 +284,8 @@ UsedLibrary="C:/Dropbox/CBA/circuits/eagle/parts/usbraw.lbr"
 [Win_1]
 Type="Schematic Editor"
 Number=1
-File="2020-06_ucbus-stepper-melted.sch"
-View="142.399 22.4818 328.676 123.78"
+File="C:/dropbox/cba/advisory/bhutan/2021-09-14_lora/2021-07-20_loRA-jake.sch"
+View="32.1497 9.16998 132.794 77.8767"
 WireWidths=" 0.0762 0.1016 0.127 0.15 0.2 0.2032 0.254 0.3048 0.4064 0.508 0.6096 0.8128 1.016 1.27 2.54 0.1524"
 PadDiameters=" 0.254 0.3048 0.4064 0.6096 0.8128 1.016 1.27 1.4224 1.6764 1.778 1.9304 2.1844 2.54 3.81 6.4516 0"
 PadDrills=" 0.2 0.25 0.3 0.35 0.4 0.45 0.5 0.55 0.65 0.7 0.75 0.8 0.85 0.9 1 0.6"
@@ -325,20 +324,20 @@ ArcDirection=0
 AddLevel=2
 PadsSameType=0
 Layer=91
-Views=" 1: 142.399 22.4818 328.676 123.78"
+Views=" 1: 32.1497 9.16998 132.794 77.8767"
 Sheet="1"
 
 [Win_2]
 Type="Board Editor"
 Number=2
-File="2020-06_ucbus-stepper-melted.brd"
-View="8.9747 13.925 33.6679 40.1306"
+File="C:/dropbox/cba/advisory/bhutan/2021-09-14_lora/2021-07-20_loRA-jake.brd"
+View="12.7615 -1.4366 44.9353 36.7389"
 WireWidths=" 0.8 0.9 0.1 0.05 0.5 0 0.3 0.2032 0.1524"
 PadDiameters=" 0.254 0.3048 0.4064 0.6096 0.8128 1.016 1.27 1.4224 1.6764 1.778 1.9304 2.1844 2.54 3.81 6.4516 0"
-PadDrills=" 0.2 0.25 0.3 0.35 0.4 0.45 0.5 0.55 0.65 0.7 0.75 0.8 0.85 0.9 1 0.6"
+PadDrills=" 0.2 0.25 0.3 0.35 0.4 0.45 0.5 0.55 0.65 0.7 0.75 0.8 0.9 1 0.6 0.85"
 ViaDiameters=" 0.55 0.6 0.65 0.7 0.75 0.8 0.85 0.9 0.95 1 1.05 1.1 1.15 1.2 1.3 0"
-ViaDrills=" 0.2 0.25 0.45 0.5 0.55 0.6 0.65 0.7 0.75 0.8 0.85 0.9 1 0.35 0.4 0.3"
-HoleDrills=" 0.2 0.25 0.3 0.4 0.45 0.5 0.55 0.6 0.65 0.7 0.75 0.8 0.85 0.9 1 0.35"
+ViaDrills=" 0.2 0.25 0.45 0.5 0.55 0.6 0.65 0.7 0.75 0.8 0.9 1 0.35 0.4 0.3 0.85"
+HoleDrills=" 0.2 0.25 0.3 0.4 0.45 0.5 0.55 0.6 0.65 0.7 0.75 0.8 0.9 1 0.35 0.85"
 TextSizes=" 0.254 0.3048 0.4064 0.6096 0.8128 1.27 1.4224 1.6764 1.9304 2.1844 2.54 3.81 5.08 6.4516 1.778 1.016"
 PolygonSpacings=" 0.254 0.3048 0.4064 0.6096 0.8128 1.016 1.4224 1.6764 1.778 1.9304 2.1844 2.54 3.81 5.08 6.4516 1.27"
 PolygonIsolates=" 0.254 0.3048 0.4064 0.6096 0.8128 1.016 1.27 1.4224 1.6764 1.778 1.9304 2.1844 2.54 3.81 6.4516 0"
@@ -348,7 +347,7 @@ DimensionExtWidths=" 0.127 0.254 0.1 0.13 0.26 0"
 DimensionExtLengths=" 1.27 2.54 1 2 3 0"
 DimensionExtOffsets=" 1.27 2.54 1 2 3 0"
 SmdSizes=" 0.3048 0.1524 0.4064 0.2032 0.6096 0.3048 0.8128 0.4064 1.016 0.508 1.27 0.6604 1.4224 0.7112 1.6764 0.8128 1.778 0.9144 1.9304 0.9652 2.1844 1.0668 2.54 1.27 3.81 1.9304 5.08 2.54 6.4516 3.2512 1.27 0.635"
-WireBend=3
+WireBend=1
 WireBendSet=0
 WireCap=1
 MiterStyle=1
@@ -370,7 +369,7 @@ SwapLevel=0
 ArcDirection=0
 AddLevel=2
 PadsSameType=0
-Layer=15
+Layer=1
 
 [Win_3]
 Type="Control Panel"
diff --git a/firmware/stepper-drop/src/config.h b/firmware/stepper-drop/src/config.h
index fea257a503a6b17bdcd5f109e9d5430ecb85c33e..05c5713a5593c0e2ef9c7d0f5ed0103d70ae7be3 100644
--- a/firmware/stepper-drop/src/config.h
+++ b/firmware/stepper-drop/src/config.h
@@ -4,11 +4,16 @@
 
 // for the bus: head, or drop? 
 //#define UCBUS_IS_HEAD
+// *genuine* max is 63 ! 
+#define UCBUS_MAX_DROPS 32
 #define UCBUS_IS_DROP
 // and D21 or D51?
 #define UCBUS_IS_D51
 //#define UCBUS_IS_D21 
 
+// 3, 2, or 1 MBaud: 
+#define UCBUS_BAUD 2
+
 // if you're using the 'module board' https://gitlab.cba.mit.edu/jakeread/ucbus-module
 // the first (og) revision has an SMT header, and some of the RS485 pins are varied, 
 // set this flag. otherwise, if you have thru-hole JTAG header, comment it out 
diff --git a/firmware/stepper-drop/src/main.cpp b/firmware/stepper-drop/src/main.cpp
index e82c36d2e5d5cb907004e9c86866cdde1c82708a..64702eaf66d4968cd251de8ba5ef1b92f5c21dec 100644
--- a/firmware/stepper-drop/src/main.cpp
+++ b/firmware/stepper-drop/src/main.cpp
@@ -158,7 +158,7 @@ void setup() {
   // ports 
   vt_usbSerial_setup();
   osapAddVertex(vt_usbSerial);    // 0
-  vt_ucBusDrop_setup();
+  vt_ucBusDrop_setup(true, 0);
   osapAddVertex(vt_ucBusDrop);    // 1
   // axis pick 
   osapAddVertex(axisPickEp);      // 2
diff --git a/firmware/stepper-drop/src/osape-d51 b/firmware/stepper-drop/src/osape-d51
index 0ae34dd7e5bca95f22725a970c2c2eb69e55ddb2..23064339e200c3819af8bc55988b57d3eaa28a2e 160000
--- a/firmware/stepper-drop/src/osape-d51
+++ b/firmware/stepper-drop/src/osape-d51
@@ -1 +1 @@
-Subproject commit 0ae34dd7e5bca95f22725a970c2c2eb69e55ddb2
+Subproject commit 23064339e200c3819af8bc55988b57d3eaa28a2e