View source for SSD1306 128x64 I2C OLED Display

'''Hardware'''
[[File:SSD1306 OLED I2C.png|right|thumb]]

 These displays use the SSD1306 controller: https://cdn-shop.adafruit.com/datasheets/SSD1306.pdf
 D0     SCL - I2C Clock signal
 D1     SDA - I2C Data signal
 RES#   This pin is reset signal input. When the pin is pulled LOW, initialization of the chip is executed.
        Keep this pin HIGH (i.e. connect to VDD) during normal operation.
 D/C#   In I2C mode, this pin acts as SA0 for slave address selection.
        LOW:  I2C Address 0x3C
        HIGH: I2C Address 0x3D
 Notes:
 The SSD1306 is capable of using a 400KHz I2C clock
 
 If you're not sure if your device's I2C address 0x3C or 0x3D, you can run the Arduio "i2c_scanner" example program
 '''File->Examples->Wire->i2c_scanner'''
 This should identify your connected SSD1306 chip as either 0x3C or 0x3D.

'''Connections'''
 '''Display  Arduino'''
   GND    Ground
   VCC     +5V
   SCL     A5
   SDA     A4

[[File:ClockTiming.png|1200px]]<br>
 We can see the Arduino is using a 400KHz clock
 The I2C address is 0x3C

[[File:I2C_FrameTime.png|1200px]]<br>
 Capture showing the time it takes to send a complete frame ~37ms


'''Software'''
 For Arduino, the Adafruit SSD1306 library, version 2.4.2, works very well.
 For testing, I used libraries\Adafruit_SSD1306\examples\ssd1306_128x64_i2c.ino example.
 Although the example calls out pin 4 as OLED_RESET, this isn't required.
 The example uses I2C address, 0x3D for the display, with the comment, "Address 0x3D for 128x64".
 Since the I2C address is dependent on the D/C# signal connection on the module, this is module dependant.
 '''My module uses I2C address 0x3C.'''


'''Source Code Modification'''<br>
This was required for my display to work<br>
  // SSD1306_SWITCHCAPVCC = generate display voltage from 3.3V internally
  if(!display.begin(SSD1306_SWITCHCAPVCC, '''0x3C''')) { // Address 0x3D for 128x64 (This is defined by the module)
    Serial.println(F("SSD1306 allocation failed"));
    for(;;); // Don't proceed, loop forever
  }


'''Additional Resources'''
 https://www.robot-electronics.co.uk/i2c-tutorial