As you may remember, someone made SD card sized Arduino before.....

Yeah, I still have them and it will still work, but limited number of SD card electrode and size can not fully activate the potential of MCU. Indeed, ATMega328 has lots of digital I/O and A/D but it was a just "just fun".

This time, I think I made a successor of SDuino. It looks like a Arduino PRO? Mini? but not like that.

I believe most of function sometimes required for prototyping is ready-made.

By the very low cost and ultra rapid PCB service by pcbway.com in China enables me to make such a "highly-integrated" board. (I hit on the idea of making this on Monday, I received the PCB board on Friday, just $30 including shipment...!) As you see, all of terminal are clearly distinguishable! No more need paper sticker for it.

This is the total schematic. As a basic feature,

1. CS of SD card is D4
2. OLED is connected to I2C, with RESET D1

I think these information will be enough to activate the functions. As you see in schematic, FTDI chip is included and Arduino IDE programmable. The procedure to add board support is described in my another project. OLED is SSD1306 based, and Adafruit SSD1306 library compatible. Just you will need to write in sketch is

#include <SPI.h>
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>

#define OLED_RESET 1
Adafruit_SSD1306 display(OLED_RESET);

The pixel arrangement in programming is as follows:

It will show just 4 lines x 8 character = 32 character for 8x8 font (4 lines, 10 characters for 8x6 dots font, as same) but this is graphic display so not limited to character but graphical expression is quite easy by the sake of Adafruit GFX.

As same as another project, I would like to sell this item (assembled) at my tindie.com store.

Actual operation can be found in the following movie...

Stay tune!!!