For a project, i need to separate the initialisation, so i figure out i could use the MY_CORE_ONLY option. I didn't find any documentation about that option, so i use sketch example from the forum but that dont work. Actually i have that :

#define MY_NODE_ID 123
#define sensorid 2

#define MY_RADIO_RFM69
#define MY_RFM69_NEW_DRIVER
#define MY_RFM69_FREQUENCY RFM69_433MHZ // Set your frequency here
#define MY_IS_RFM69HW // Omit if your RFM is not "H"
#define MY_RFM69_TX_POWER_DBM 5
#define MY_RFM69_MAX_POWER_LEVEL_DBM 10

#define MY_RFM69_SPI_SPEED (4*10*1000ul)  // datasheet says 10Mhz max.

#define MY_RFM69_NETWORKID (38)
#define MY_PASSIVE_NODE //+248 B

#define MY_CORE_ONLY
#define MY_DEBUG
#define MY_DEBUG_VERBOSE_RFM69
#define MY_RFM69_IRQ_PIN 2 //DI0#define MY_RFM69_CS_PIN 10 //D8 // NSS. Use MY_RFM69_SPI_CS for older versions (before 2.2.0)


#include <MySensors-Attiny.h>

MyMessage msg(sensorid, V_TRIPPED);


void setup() {
  transportInit();
  transportSetAddress(MY_NODE_ID);

}

void presentation() {
  
//Pour le premier démarrage, on attend d'avoir un bon voltage avant de continuer
  present(sensorid, S_DOOR, "test", false);

}

void loop() {

send(msg.set(hwCPUVoltage()));
wait(10000);

}

And i get that message from serial :

0 RFM69:INIT
1 RFM69:INIT:PIN,CS=10,IQP=2,IQN=0
8 RFM69:PTX:LEVEL=5 dBm
80 !TSF:SND:TNR
10150 !TSF:SND:TNR

Someone could give some information about the my_core_only option ? Seems i miss some part.

Thx in advance :)