I'm building an Arduino switch for two different signals and I'd be very grateful if you can revise the schematic and tell me if there's something wrong or if something can be improved.
In the schematic you can see two switches (representing two different Arduino GPIO pins) with a 1k serial resistor to limit the current according to Arduino's datasheet.
The labels represents an unknown external circuit. The only thing I can say about it it's that the BJT transistor is connected to a low-power high-frequency (~870kHz) circuit, and the MOSFET is connected to a 5V high-current (~3A) circuit.
The circuit should be on if the Arduino isn't placed (thus open circuit on GPIO pins), that's why I placed a 10k pull-up on the base of the BJT transistor.