Hi, I'm having a problem getting power out from a nano. I have it connected to a USB port and its running my sketch. I need to power up 2 other small devices but when I check between 5V and Gnd (4th pin on each side from SIIP socket I don't read any voltage. So my question is with the USB connected shouldn't I be reading 5V on these pins?
I have to apologize. What we have here is a case of operator error. My multi-meter probe was not fully pushed in!
Hehe, happens to the best of use. Although the best would have checked the meter first in a strange case like this 
But keep in mind the Arduino is limited in what it can supply. If connected to USB the USB port it's connected to is the limiting factor in the amount of current so around 500mA for normal computers. And if you supply the the Arduino with 12V you can't really draw more then 100mA. Just saying because you didn't say what those "small devices" are. Extra note, a servo or a motor is NOT a small device
Yea, it was one of those Doh! moments. And in the process of trying to figure out what was wrong I fried a Nano.
So, I'm using a 9V battery as power and the other devices are 2 shields, blue tooth and an Ethernet board. Its working now.
Then you're about at the max of it all. For the onboard regulator but also because a 9V battery is a pretty pore source. Especially Ethernet is pretty energy hungry.
Do you know of a good design for battery powered nano? I'm all ears.
Easiest method? Grab a USB power bank 
Good idea