Rp2040 dual core example sketches

Question

So i have a rp2040 board, and i could not find a dual core example codes. The closest i could find is the scheduler library example given to me by the IDE

/*
 Multiple Blinks

 Demonstrates the use of the Scheduler library for the boards:
 
 - Arduino Nano 33 BLE, or
 - Arduino Portenta H7, or
 - Arduino Nano RP2040 Connect

 Hardware required :
 * None (LEDs are already conencted to RGB LED)

 ATTENTION: LEDs polarity is reversed (so loop3 will turn the LED off by writing 1)

 created 8 Oct 2012
 by Cristian Maglie
 Modified by
 Scott Fitzgerald 19 Oct 2012

 This example code is in the public domain

 http://www.arduino.cc/en/Tutorial/MultipleBlinks
*/

// Include Scheduler since we want to manage multiple tasks.
#include <Scheduler.h>

// On Nano RP2040 Connect, RGB leds are connected to the wifi module
// The user APIs are the same, but we can't convert to int, so use defines
#if defined(ARDUINO_NANO_RP2040_CONNECT)

#include "WiFiNINA.h"
#define led1  LEDR
#define led2  LEDG
#define led3  LEDB

// On Nicla Sense ME, RGB leds are connected via an I2C module
// The user APIs are the same, but we can't convert to int, so use defines
#elif defined(ARDUINO_NICLA)

#include "Nicla_System.h"
#define led1  LEDR
#define led2  LEDG
#define led3  LEDB

#else

int led1 = LEDR;
int led2 = LEDG;
int led3 = LEDB;

#endif

void setup() {
  Serial.begin(9600);

  // Setup the 3 pins as OUTPUT
  pinMode(led1, OUTPUT);
  pinMode(led2, OUTPUT);
  pinMode(led3, OUTPUT);

  // Add "loop2" and "loop3" to scheduling.
  // "loop" is always started by default.
  Scheduler.startLoop(loop2);
  Scheduler.startLoop(loop3);
}

// Task no.1: blink LED with 1 second delay.
void loop() {
  digitalWrite(led1, HIGH);

  // IMPORTANT:
  // When multiple tasks are running 'delay' passes control to
  // other tasks while waiting and guarantees they get executed.
  delay(1000);

  digitalWrite(led1, LOW);
  delay(1000);
}

// Task no.2: blink LED with 0.1 second delay.
void loop2() {
  digitalWrite(led2, HIGH);
  delay(100);
  digitalWrite(led2, LOW);
  delay(100);
}

// Task no.3: accept commands from Serial port
// '0' turns off LED
// '1' turns on LED
void loop3() {
  if (Serial.available()) {
    char c = Serial.read();
    if (c == '0') {
      digitalWrite(led3, LOW);
      Serial.println("Led turned off!");
    }
    if (c == '1') {
      digitalWrite(led3, HIGH);
      Serial.println("Led turned on!");
    }
  }

  // IMPORTANT:
  // We must call 'yield' at a regular basis to pass
  // control to other tasks.
  yield();
}

but i do not think its using the second core of the rp2040. Does anybody have an example codes? because im really lost how to do it

Answer 1

Note: This information is about the pure "Arduino" core, not the "MBED" core. The MBED core gets in the way of using the RP2040 SDK, so install the pure bare metal core from here.

By default the second core isn't doing anything.

But you can run anything you want on it directly. No need for any libraries. You use the function multicore_launch_core1(func) to start a function on that core. You could make it Arduino-like by writing a wrapper function, such as this code:

void setup2() {
    pinMode(1, OUTPUT);
}

void loop2() {
    digitalWrite(1, HIGH);
    delay(750);
    digitalWrite(1, LOW);
    delay(750);
}

void main2() {
    setup2();
    while (1) {
        loop2();
    }
}

void setup() {
    multicore_launch_core1(main2);
    pinMode(0, OUTPUT);
}

void loop() {
    digitalWrite(0, HIGH);
    delay(1000);
    digitalWrite(0, LOW);
    delay(1000);
}