Micro PinOS — Coming Soon

The operating system for your pinball machine.
"I swear it's bigger in the cabinet."

ATmega2560

ATmega2560 — MainMega.ino

void loop() {
  readRS485();
  processNextEvent();
  updateGameLogic();
  updateSolenoids();
}

ATmega328P × 5

ATmega328P — nano_universal.ino

#define MY_ADDRESS  0
#define DE_PIN      2

static const SwEntry SW[] = {
  { 3, SW_SLINGSHOT_LEFT,
    5, -1, 25, 5 },
  { 7, SW_POP_BUMPER_TOP,
    8, -1, 20, 5 },
};

RS485 Multi-Drop Bus

Bus frame format

// Nano → Mega
// "S<id>:<state>
"
// e.g. "S3:1
"

Serial1.begin(115200);
// up to 5 Nanos,
// one twisted pair

GameStyle Plugins

GameStyle interface

struct GameStyle {
  const char *name;
  void (*onInit)();
  void (*onBallReset)();
  void (*onShot)(int sw);
  void (*onTimerTick)();
  void (*onBallDrain)();
};

Non-Blocking Solenoids

millis() only — no delay()

void fireSolenoid(
    int idx,
    unsigned long ms) {
  digitalWrite(sol[idx].pin,
               HIGH);
  sol[idx].endMs =
    millis() + ms;
}

115200 Baud

Serial assignments

// Mega serial ports:
Serial1 → RS485/Nanos
Serial2 → Sound board
Serial3 → Display/LEDs

// All at 115200 baud
// noise-immune RS485

MIT License

Free to use forever

// Use it. Fork it.
// Sell machines with it.
// No royalties.
// No restrictions.
// Just build cool stuff.

Free & Open Source

commands.h — vocabulary

#define SND_BUMPER  "BUMPER"
#define SND_JACKPOT "JACKPOT"
#define LGT_LANE_F  "LANE_F"
#define LGT_FRENZY  "FRENZY_ON"

sendSound(SND_BUMPER);
sendLight(LGT_LANE_F);