#include "Arduino.h"
#include "RPC.h"
#include "SerialRPC.h"

using namespace rtos;

Thread subtractThread;

/**
   Returns the CPU that's currently running the sketch (M7 or M4)
   Note that the sketch has to be uploaded to both cores.
 **/
String currentCPU() {
  if (RPC.cpu_id() == CM7_CPUID) {
    return "M7";
  } else {
    return "M4";
  }
}

void setup() {

  pinMode(LED_BUILTIN, OUTPUT);
  // Initialize RPC library; this also boots the M4 core
  Serial.begin(115200);
  if (!SerialRPC.begin()) {
    Serial.println("RPC initialization fail");
  }
}

void loop() {

  if (currentCPU() == "M4") {
    if (SerialRPC.available()) {
      char read= (char)SerialRPC.read(); // Fill the buffer with characters
      if (read=='1') digitalWrite(LED_BUILTIN, HIGH);
      else digitalWrite(LED_BUILTIN, LOW);
    }
  }

  if (currentCPU() == "M7") {
    SerialRPC.print('1');
    delay(1000);
    SerialRPC.print('0');
    delay(1000);
  }
}