ssd1306_spi_maxfps.ino

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

#define OLED_DC     6
#define OLED_CS     7
#define OLED_RESET  8
Adafruit_SSD1306 display(OLED_DC, OLED_RESET, OLED_CS);

int frames;
unsigned long startTime;
unsigned long endTime;

void setup() {

  // initialise the SSD1306
  Serial.begin(9600);
  display.begin(SSD1306_SWITCHCAPVCC);

  // setup font
  display.setTextSize(4);
  display.setTextColor(WHITE);

  // display
  frames = 0;
  startTime = millis();
}


void loop() {
  // dump the frame rate every 100 frames
  if (frames == 100) {
    
    endTime = millis();
    float seconds = (endTime - startTime) / 1000.0;
    float fps = ((float)frames) / seconds;

    display.clearDisplay();
    display.setCursor(0, 0);
    
    char str[8]; // probably too big
    sprintf(str, "%u fps", round(fps));

    display.print(str);

    startTime = millis();
    frames = 0;
  }

  display.display();
  frames++;
}