Monday, July 20, 2020

Arduino OLED display shield

The 2.4" I2C OLED display I had sitting idle is too big for the "Promini OLED Clock shield", yet a perfect candidate for a regular Arduino shield. This is how it looks soldered on a prototype shield with two buttons on top, attached to wsduino running the OLED Clock sketch (each of the 5 faces shown):

The current sketch uses U8glib library and takes about 27k of ATmega328's 31k program memory. It could be enhanced by adding alarm (buzzer, relay etc.), since most of the digital pins are available (only D3 and D9 are used for the 2 buttons). Adding NTP time sync (with an ESP8266 module) could also be done, but one/some of the faces will need to be dropped because of memory constraints. All these are exercises/homework for the inquiring minds :)

Note: My nice beveled 2.42" OLED does not seem to be so ubiquitous.

 A quick search on ebay for similar 2.42" OLED displays returns a different style, already mounted on a larger PCB:

This may fit on the Arduino protoshield, but it may look bulky.


  1. I've been using the 2.42" OLED on the promini OLED Clock shield for several years. I used a self-stick foam pad on the back of the display to protect it from the battery. I found the white OLED eventually burned the phosphor. I switched to a yellow display and haven't had a problem yet.

    1. Thanks Mike. Interesting fact. Then I will avoid the white display in favour of the yellow one. Blue should be nice, but I haven't seen one in 2.42" size.