Duty cycle limitation – Softserial is not suitable for high duty cycle and “chatty” applications that occupy too much processor time like OSD and serial RX.Nothing is perfect, there are some disadvantages in using Soft Serial: With Softserial, you can connect SmartPort directly to the FC without performing the uninversion hack. This is extremely useful for F1 and F4 flight controllers as they don’t have built-in inverters. This allows you to free up a whole UART for something else.Īnd Soft Serial also supports inverted signal like Smart Port. you can use UART1 TX pin for SmartAudio or SmartPort if you set it to Soft Serial. For example if you use UART1 RX pin for ESC Telemetry. You can even “split“ one UART for two things.
With the limited number of UART’s on a flight controller (only 2 or 3 on F3/F4 boards), you can turn unused pins like LED_Strip or PPM into softserial ports for connecting additional devices. Stuff that requires a UART connection but not timing critical, such as:
