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OLED Digital Clock With Arduino Pro-mini

This is digital clock using 0.91 inch OLED and arduino pro-mini.

It’s the first time for me to utilize the very small OLED display and tiny pro-min board.

Therefore, simple project is chosen as digital clock making is relatively easy and not much complex.

While making the circuit above, I need to handle several challenges like below.


- Pro-mini board type is very confusing as 3.3v and 5v type of boards are available

- As pro-mini board lacking USB interface for programming, additional break-out board (USB to serial programmer) is necessary for uploading sketch code

- 0.91 inch OLED is using I2C interface and DS3231 real time clock module also using I2C for communication

- Choosing correct voltage regulator is necessary for power up the clock circuit


When you using arduino Uno or Micro boards, circuit wiring and uploading program is very easy as there are many how-to contents are available in Internet.

But for the simple project such as clock making, personally thinking that using expensive Uno or micro boards is a kind of luxury. .

That’s why I’m choosing pro-min board as its price is the half of Uno and Micro boards.

But according to the how-to in several web-pages I saw, pro-mini is a little bit special for configuring and using it.

Let’s start story about making digital clock with pro-mini.”

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