https://www.arduino.cc/en/Products.Compare
http://tronixstuff.com/2013/12/12/arduino-tutorials-chapter-22-aref-pin/

Uni R3

https://store-usa.arduino.cc/products/arduino-uno-rev3
INPUT VOLTAGE (LIMIT) 6-20V 、 7-12V
DC CURRENT PER I/O PIN 20 mA

OLED

  • I2C: 100Khz - 3.4Mhz, many devices on the same bus
  • SPI: 4Mhz and up to 100Mhz

IDE

  • Sketch Menu -> Include Library -> Manage Libraries
  • Search: BusIO + adafruit ssd1306
  • File -> Examples

SSD1306 Oled display: https://create.arduino.cc/projecthub/Arnov_Sharma_makes/0-96-inch-oled-getting-started-guide-78163a

// Declaration for an SSD1306 display connected to I2C (SDA, SCL pins)
// The pins for I2C are defined by the Wire-library. 
// On an arduino UNO:       A4(SDA), A5(SCL)
// On an arduino MEGA 2560: 20(SDA), 21(SCL)
// On an arduino LEONARDO:   2(SDA),  3(SCL), ...

  • File -> Examples —> ssd1306_128x32_spi

    // Declaration for SSD1306 display connected using software SPI (default case):

    define OLED_MOSI 9

    define OLED_CLK 10

    define OLED_DC 11

    define OLED_CS 12

    define OLED_RESET 13

Cases

Pro Mini Mount: https://www.thingiverse.com/thing:2457807