I have made board with tiny OLED display, based on SSD1306. SSD1306 has embedded voltage up-converter and just putting capacitor is enough and it is quite handy. But, I guess, all color OLED chip, like SSD1331, 1332, ... does not have up-converter and we have to prepare high voltage (12V) for driving.

In the schematic, right-top part is a switching up-converter from 3.3 V to 12 V. Actually for USB bus drive operation, voltage is converted from 5.0 V to 3.3 V to 12 V because not always 5.0 V is available.

So, as a power supply, ULTRA color work with

(case a) 5.0 V drive, applying between 5V and GND terminal on board

(case b) USB bus drive. 5V is provided from USB

(case c) 3.3 V drive, applying between VC and GN terminals on board

In any case, system voltage is 3.3 V (ATmega1284P runs at 3.3 V/16 MHz)

For programming purpose,

CS of OLED: D8
RES of OLED: D9
D/C of OLED: D10

CS of micro SD: D4

those are enough for program. The OLED display can work with SSD_13XX library written by SUMOTOY

#include <SPI.h>
#include <SSD_13XX.h>

#define __CS1 	8
#define __DC 	10
#define __RST 9

SSD_13XX tft1 = SSD_13XX(__CS1, __DC,__RST);

are the description for OLED driving.

Actual operation can be found in the following movie. As same, I have a plan to sell this board at tindie.com stay tune if you have some interest!