U3 and U5 in schematic

[WellsWang]

Should U3 be 1117-3.3? provide a 3.3v power source? Spec of U5 is 26Mhz active crystal oscillator？

Thanks.

[jjmz]

Yes U3 is a 3.3 voltage regulator - 1117-3.3 is just fine.

U5 is a Crystal oscillator : ordered this one : https://fr.farnell.com/multicomp/mcsjk-6nc2-26-00-25-b/oscillateur-26mhz-7mm-x-5mm-cmos/dp/2854378