8 PWM inputs;
S-Bus input, with built in inverter;
Spektrum Satellite receiver input with 3.3V regulator;
8 ESC outputs;
Two UARTs (excluding the dedicated S-Bus input);
MPU6050 gyro/accelerometer but no magnetometer (compass) or barometer. This uses I2C so the max gyro update rate is about 2 kHz.
8 MB flash for blackbox logging. This is the same as the original SP Racing F3 board, but only half of the amount the X-Racer F303 has.
SiLabs CP2102 hardware USB to serial bridge (not a software virtual com port implementation). This means the Cleanflight/Betaflight configurator does not need to be reconnected after the flight controller is rebooted, for example on exiting from command prompt mode, because the CP2102 can remain connected to the PC while the CPU reboots.