Arduino leg of SCK can be connected to CLK of RTC module?

Question

Arduino

Considering that
1. nokia 5110 screen is already sitting on this leg
2. mikro SD-Card
RTC module on DS1302

Answer 1

Can. Judging by the description, the interface of the microcircuit is the usual SPI. Combining clock and data signals is perfectly acceptable. The clock chip itself is low-power, so there will not be much "eat off" from the microcontroller. It is important to remember the following: for the Atmega 328 , the total current through all pins must not exceed 200 mA.