Pro Micro RP2040 dual core question

Other
1

I am using the Arduino IDE and all code is in C/C++.

My old configuration was a Pro Micro as the master talking to a second Pro Micro as a slave over the I2C bus. It works fine except I ran out of program store on the master. Upgrading to the Pro Micro RP2040 solved that problem nicely. I am now eyeing that second core and want to move the code running on the slave to it. I copied and pasted the slave code and, to no surprise, ran into a massive number of duplicate defined variables. The variables that are constants aren’t a problem but many have different values over time on each processor. Before I go through the pain of renaming these variables on my slave, is there a way to tell the compiler to isolate the code on each core?

Thanks in advance,

Rick

I also wonder what will happen with the master-slave communications. Will the master send an I2C command from core 0 and core 1 see it on the same I2C interface? That would save me changing some code.

2

Do you really need to rename every variable? How about wrapping them in a namespace?

3

It sure looks like namespace should solve my problem but I’m confused by the examples I found.

If I say:

namespace qaz
{
-my entire program which is self contained-
}

will this work or must I add qaz:: in front of each variable and function?

Thanks,
Rick

4

You can use two isolated namespaces.

namespace core0 {
  int counter = 0;

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

  void loop() {
    Serial.println("Core0 running");
    delay(1000);
  }
}

namespace core1 {
  int counter = 100;

  void loop() {
    while (true) {
      counter++;
      delay(500);
    }
  }
}

void setup() {
  core0::setup();
  multicore_launch_core1(core1::loop);
}

void loop() {
  core0::loop();
}

Each namespace will have its own variables and functions. No variable renaming will be needed. Functions and variables will be accessed only via namespace prefixes.

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5

For me, namespace didn’t isolate the groups of variables. I ended up finding each duplicate definition and resolving it. I also found that multicore_launch_core1(core1::loop) caused the processors to brick. If I just ran setup(), loop(), setup1(), and loop1() it worked fine. I do have in loop() the call to loop1();

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6

Good work - happy to hear it’s goin’ now

7

I think the coders have done amazing things to make the dual core architecture easier to use. However, the supporting documentation has not caught up yet as far as I can tell.

8

Here is a dual core Hello World:

void setup()
{
Serial.begin(19200); // USB
}
void loop()
{
Serial.println(“hello world from core 0”);
delay(2000);
}

void setup1()
{
delay(1000);//to offset prints
}
void loop1()
{
Serial.println(“hello world from core 1”);
delay(2000);
}

1 Like