PWM.ino

#include "SPI.h"
#include "Adafruit_GFX.h"
#include "Adafruit_ILI9341.h"

// For the Adafruit shield, these are the default.
#define TFT_DC 9
#define TFT_CS 10

Adafruit_ILI9341 tft = Adafruit_ILI9341(TFT_CS, TFT_DC);

const int CV = 6;
const int CV_ON = 255;
const int CV_OFF = 0;

const int DELAY = 2000;

void setup() {                
  pinMode(CV, OUTPUT);
  randomSeed(analogRead(0));

  tft.begin();

  uint8_t x = tft.readcommand8(ILI9341_RDMODE);
  x = tft.readcommand8(ILI9341_RDMADCTL);
  x = tft.readcommand8(ILI9341_RDPIXFMT);
  x = tft.readcommand8(ILI9341_RDIMGFMT);
  x = tft.readcommand8(ILI9341_RDSELFDIAG);

  showText("Booting up");
}

void loop() {
  triggerRand();
  delay(DELAY);
  triggerOff();
  delay(DELAY);
}

void triggerRand() {
  int randValue = random(255);
  analogWrite(CV, randValue);
  showText("Trigger: " + String(randValue));
}

void triggerOn() {
  analogWrite(CV, CV_ON);
  showText("Trigger: ON");
}

void triggerOff() {
  analogWrite(CV, CV_OFF);
  showText("Trigger: OFF");
}

unsigned long showText(String msg) {
  tft.fillScreen(ILI9341_BLACK);
  unsigned long start = micros();
  
  tft.setCursor(0, 0);
  tft.setTextColor(ILI9341_WHITE);
  tft.setTextSize(3);
  tft.println(msg);
  return micros() - start;
}