I'm looking to power 5 Arduino Nano devices and an Uno. I'm wondering if I can power the devices with one power supply. I know that I'll need to use the VIN pin with 7-12v since the 5v will be used for another device. Is it possible to power the 5 Nanos with one single power supply?
Yes it is possible, you can connect 5 Arduino nano on a single power supply all you need to check is the power rating of the arduino nano. That is Arduino nano requires 7v to 12v of input voltage and around 500mA of input current. Now if you want to connect 5 Arduino nano you have to connect them in parallel connection and have to use a power supply having output rating of 12v with atleast 2.5A current. You have 5 Arduino nano therefore minimum current required will be 5*500mA = 2.5A.
Power everything from a 5V wallwart. Then you are not dependent on the 150mA from the Nano regulator.