add sbus note re inversion

ArduPilot · Aug 28, 2023 · fe081aa · fe081aa
1 parent 1267c95
commit fe081aa
Showing 1 changed file with 1 addition and 1 deletion.
diff --git a/common/source/docs/common-rc-systems.rst b/common/source/docs/common-rc-systems.rst
@@ -73,7 +73,7 @@ These bi-directional protocols require the use of a Serial Port. See links below
 RC input to Serial Port
 -----------------------
 
-.. note:: ArduPilot firmware releases 4.0 and later, any UART RX input will auto-detect all the protocols (except PPM or SRXL2/CRSF/ELRS which also require connection of the UART's TX pin), if the serial port protocol is set to 23 (for example :ref:`SERIAL2_PROTOCOL<SERIAL2_PROTOCOL>` for the TELEM2 UART is used).
+.. note:: any UART RX input will auto-detect all the protocols (except PPM, or SRXL2/CRSF/ELRS which also require connection of the UART's TX pin), if the serial port protocol is set to 23 (for example, generally, :ref:`SERIAL2_PROTOCOL<SERIAL2_PROTOCOL>` for the TELEM2 UART if used). The exception to this is for SBUS attached to UARTs on F4 based autopilots. This requires an external inverter since SBUS is inverted and F4 autopilots do not have selectable inversion on their UART pins.
 
 .. note:: The serial port baudrate is automatically set and controlled by the firmware when any serial RC protocol is detected.