How to Use SmartPort Telemetry Data Transmission on F405v4 Flight Controller

The SmartPort protocol is a reverse protocol, and the F4 flight controller cannot directly read the reverse signal,

therefore, when using the S.Port protocol, the F4 flight controller needs to connect to the receiver through a software UART

You can map the flight controller's CC pad or LED pad as a software UART

However, after mapping it as a software UART, the Camera Control function or LED function will become unavailable.

Method 1: Map the LED pad as a software UART (without using the LED function).

（1）Please refer to the wiring diagram below and connect the S.Port signal wire to the flight controller's LED pad.

（2）If you are using Betaflight 4.4.0 or above firmware, please reflash the flight controller firmware and select the "SmartPort" telemetry data transmission protocol during the firmware flashing process (it is not enabled by default under the default options).

（3）Open the flight controller's CLI  page and enter the following commands:

feature SOFTSERIAL
feature TELEMETRY
resource LED_STRIP 1 none
resource SERIAL_TX 11 A08
serial 30 32 115200 57600 0 115200
set tlm_inverted =off
set tlm_halfduplex = ON

save

After completing the above steps, you can now use SmartPort telemetry data transmission.

Method 2: Map the CC pad as a software UART (without using the Camera Control function).

（1）Please refer to the wiring diagram below and connect the S.Port signal wire to the flight controller's CC pad.

（2）If you are using Betaflight 4.4.0 or above firmware, please reflash the flight controller firmware and select the "SmartPort" telemetry data transmission protocol during the firmware flashing process (it is not enabled by default under the default options).

（3）Open the flight controller's CLI page and enter the following commands:

feature SOFTSERIAL
feature TELEMETRY
resource CAMERA_CONTROL 1 none
resource SERIAL_TX 11 B14
serial 30 32 115200 57600 0 115200
set tlm_inverted =off
set tlm_halfduplex = ON

save

After completing the above steps, you can now use SmartPort telemetry data transmission.

Notice:

1. Please use the regular S.Port output to connect to the flight controller, and do not use the "non-inverted Smart.Port" signal to connect to the flight controller.

2. When using "Method 2" to map the CC pad as a soft serial port,

you enter the command "resource CAMERA_CONTROL 1 none," and an error occurs.

This is because the Camera Control function was not enabled during firmware flashing, and it is a normal phenomenon that you do not need to worry about.