Connecting external power and FTDI adapter?

[Cliff Karlsson]

I have a Arduino pro mini 5v where I have attached a couple of 5v sensors. I am using an external 5v powersupply and it is powering the sensors directly and also the arduino from the Vin/Gnd.

I tried connecting the arduino to a 3.3v usb ftdi adapter without using the power supply to upload sketches and to use the serial monitor and it worked. But how do I power all the sensors from the power supply and also connect the ftdi-adapter at the same time without frying anything?

[mfalkvidd]

@Cliff-Karlsson Use the external powersupply and connect the ftdi as usual, but skip the power pin. That's it. All ftdis I've seen can handle 5V on rx/tx. If you want to be really sure, check the datasheet of your particular ftdi model.

[NeverDie]

Or use a level shifter.