The most popular RTC for the Arduino is the DS1307. However, it does have some drawbacks, the most notable of which is that its operating voltage is 5v, which means it cannot be used with 3.3v ...

Posted in Arduino Hacks, clock hacks Tagged 1307 RTC, arduino nano, Berlin clock, blinkenlights, clock, set theory, set theory clock, shift registers Coin-Op Weather July 8, 2015 by Dan Maloney 1 ...

Having trawled though Arduino's just-released Uno R4 literature, here are the Uno R4 WiFi and R4 Minima in a nutshell: Features common to Arduino R4 ... (MCU RTC power pad held to 5V rail on Minima) ...