I am laying out a custom board and want to use the NANO as the main chip and a data logging shield.
it appears that the NANO does not have 3.3v out unless it is powered by the USB as the USB provides the 3.3v regulator.
it also appears that the data logging shield does not have it's on voltage regulator.
any suggestions on how to add a VR on the shield that will not be problem if the shield is used with a an UNO at some point ?
You can use the 3.3V output of the Nano board. I think it can do up to 50mA.
Only with very old versions, the 3.3V was not available without the usb connected.
Use ASM1117-3.3V regulator. I have in on my custom board with SD card slot and ATMEGA328.
Voltage Regulator 3.3V/1A SOT223 AMS1117-3.3
Dipmicro.com part number: DE4113
I am using Itead_IC_110429 EAGLE library and the part has SOT-223 foot print so any decent library should have its foot print.
Remember, the tab is NOT connected to ground, but to output instead. I made the mistake once.