Hello everyone!
I was just making my first arduino standalone project; with lots of i2c communication. It was all going right until y plugged it to DC instead of USB. It starts all right, but the readings that it gets from the devices are different from the readings when it's usb powered. For example the RTC (in breakout board) displays the right time un usb, but in DC; it displays numbers out of hour range (EG. 90 minutes or 32 hours). Also between very simple buttons connected to digital pins 3 to 7, all pulled down properly, arduino detects a constant push of the button 7.
I deleted every serial communication line; and pulled down RX & TX pins with no different result.
So rather than a precise code correction (large code), what i want to figure out are the differences between USB power and DC, using 5V, arduino UNO, that could be giving these execution unexpected results.
I googled a lot, but i couldn't figure out the good search terms to find help. Obviously someone else should have had the same problem.
Thank you, very much!