Ssd1306 And Particle

YOU MUST CONNECT MOSI (DATA) and CLK

// use hardware SPI

// OLED_D0 -> A3 (SPI CLK)

// OLED_D1 -> A5 (SPI MOSI)

#define OLED_DC     D3

#define OLED_CS     D4

#define OLED_RESET  D5

You must remove this function

int random(int maxRand) {

   return rand() % maxRand;

}