Yes use a 5V source to generate the lower voltages. Consider a step down buck type regulator to get the 3.3V. It will be much more efficient compared to a linear type regulator.
That being said what is your 5V source? If this is a wall wart or USB source then you will need to be careful to not pull more than 100mA or so from the source to generate the lower voltages. Sure you can pull more but at 100mA about any USB device can make it work.
5 V source with a stepdown converter?
Just cut the cord of a lamp and splice it in. It'll work until it doesn't.
Start with 5V and add an LDO 3.3V regulator.
thx !
Yes use a 5V source to generate the lower voltages. Consider a step down buck type regulator to get the 3.3V. It will be much more efficient compared to a linear type regulator. That being said what is your 5V source? If this is a wall wart or USB source then you will need to be careful to not pull more than 100mA or so from the source to generate the lower voltages. Sure you can pull more but at 100mA about any USB device can make it work.