Will a USB cable with no 5V still work?

I'm working with a NANO based system and testing various power schemes, so I don't want the 5V from the USB to be included. If I make a cable with the 5V wire cut, and the device is getting its power elsewhere, will I still be able to program and do serial monitoring with just the D+, D- and GND?

I’m going to guess yes. There are USB devices with their own separate power supply and no connection to USB power and I don’t see why the Nano can’t work that way. (Of course devices like normally use a regular USB cable, but USB power is not connected to anything inside the device.)

DVDdoug:
I'm going to guess yes. There are USB devices with their own separate power supply and no connection to USB power and I don't see why the Nano can't work that way. (Of course devices like normally use a regular USB cable, but USB power is not connected to anything inside the device.)

Thanks. I don't have an actual schematic, but I thought maybe the USB driver chip itself just might get its power exclusively from that source. I guess its not a big sacrifice to just try it and see for sure.

I took a look at the Nano Schematic, and Yes, it will work. The FT232RL IC that converts USB to RS232TTL is powered by the +5 bus, which is supplied by, both, the USB "VBUS" line (from the USB connection) through a protection diode, AND by the Linear Regular that drops Vin to 5V. It's unclear whether the NANO can be supplied by a direct connection to the +5V output [the Arduino Uno can, but the circuit is a little different]. It depends on whether or not the LM1117IMPX-5.0 IC can survive such a connection.

So, as long as +5V is supplied externally, then no need for the USB powerline.

ReverseEMF:
I took a look at the Nano Schematic, and Yes, it will work. The FT232RL IC that converts USB to RS232TTL is powered by the +5 bus, which is supplied by, both, the USB “VBUS” line (from the USB connection) through a protection diode, AND by the Linear Regular that drops Vin to 5V. It’s unclear whether the NANO can be supplied by a direct connection to the +5V output [the Arduino Uno can, but the circuit is a little different]. It depends on whether or not the LM1117IMPX-5.0 IC can survive such a connection.

So, as long as +5V is supplied externally, then no need for the USB powerline.

Ah thanks! And yes… the 5V pin will survive external power. BTW… can you share a link to the NANO schematic?

PeterPan321:
BTW... can you share a link to the NANO schematic?

Right-chere: