add some pinouts to README

README.md

@@ -10,6 +10,7 @@
 - TTL-level DMX: FWS 
 - Limit switches: EXP2 (optional)
 - Address selector: EXP1 (optional)
+- VM/VBB(?) Jumper must be set on every motor driver
 
 ## DMX Registers
 
@@ -50,6 +51,36 @@ open serial RTT prints:<br />
 open cgdb debugger:<br />
 `./debug.sh`
 
+## non-obvious PinOuts
+
+### DMX/UART/FWS
+| Pin # | connect to RS485 Transceiver
+| - | ----------|
+| 1 | NC        |
+| 2 | DATA-in   |
+| 3 | GND       |
+| 4 | 5V  (only connect if not powered by other board) |
+
+
+### Limit Switches/EXP2
+|Pin #| Switch    |Pin #| Switch    |
+| --- | ----------| --- | ----------|
+|  1  | M1 (PB14) |  2  | M2 (PB13) |
+|  3  | M3 (PF7)  |  4  | M4 (PB12) |
+|  5  | M5 (PE7)  |  6  | M6 (PB11) |
+|  7  |           |  8  |           |
+|  9  | GND       | 10  |           |
+
+### Address Selector/EXP1
+|Pin #| Switch    |Pin #| Switch    |
+| --- | ----------| --- | ----------|
+|  1  |           |  2  |           |
+|  3  |           |  4  |           |
+|  5  |           |  6  |           |
+|  7  |           |  8  |           |
+|  9  | GND       | 10  | 5V        |
+
+
 ## Hardware
 
 - BIGTREETECH Manta M8P v1.1