Compilation error when using LowPower.h library with MySensors

[SuperNinja]

Hi all,
I would like to put my node on deepsleep (328p + rfm69hcw + battery):

• I first used the sleep () but I did not go lower than 3.7mA
• I saw on this topic https://forum.mysensors.org/topic/1478/rfm69-sleep-mode?_=1610979868641 that we could go lower with LowPower.h with

LowPower.powerDown (SLEEP_8S, ADC_OFF, BOD_OFF);

• I succeeded with going down to 17µA BUT ONLY with the lowpowerlab libraries

• if I include LowPower.h in my MySensors sketch :

//===== RFM config =====
#define MY_RADIO_RFM69
#define MY_IS_RFM69HW //with H(CW)
#define MY_RFM69_NEW_DRIVER
#define MY_RFM69_FREQUENCY  RFM69_868MHZ
#define MY_SIGNAL_REPORT_ENABLED

#define MY_RFM69_IRQ_PIN 2
#define MY_RFM69_CS_PIN 10

//===== LOWPOWERLAB =====
#include <LowPower.h> //get library from: https://github.com/lowpowerlab/lowpower
//writeup here: http://www.rocketscream.com/blog/2011/07/04/lightweight-low-power-arduino-library/

#include <MySensors.h>

//========== TRANSMISSION ID ==========
#define CHILD_ID_RX_RSSI        (4)

//pr1: ===== vcc =====
#include <Vcc.h>                      //https://github.com/Yveaux/Arduino_Vcc
const float VccMin   = 0.0;           // Minimum expected Vcc level, in Volts.
const float VccMax   = 3.3;           // Maximum expected Vcc level, in Volts.
const float VccCorrection = 3.32 / 3.29; // Measured Vcc by multimeter 4.97 divided by reported Vcc 4.88
Vcc vcc(VccCorrection);
#define CHILD_ID_VCC        (10)

//pr2: ===== sleep =====
unsigned long SLEEP_TIME = 60000;           // Sleep time between reads (in milliseconds) 60000=1minute

//========== Initialize general MESSAGE ==========
MyMessage msgRxRSSI(CHILD_ID_RX_RSSI, V_CUSTOM);
MyMessage msgVcc(CHILD_ID_VCC, V_VOLTAGE);

//===================================
//=              BEFORE              =
//===================================
void before()
{

} //FIN de before

//===================================
//=              SETUP              =
//===================================
void setup() {//no need Serial.begin(115200)

}//FIN du SETUP
//==========================================
//=              PRESENTATION              =
//==========================================
void presentation()
{
  // Send the sketch version information to the gateway and controller
  sendSketchInfo("ATC_report & Vcc", "1.0");

  // Register all sensors to gw (they will be created as child devices)
  present(CHILD_ID_RX_RSSI, S_CUSTOM, "RX RSSI");
  present(CHILD_ID_VCC, S_MULTIMETER, "Vcc");

} // FIN de PRESENTATION
//===================================
//=              LOOP               =
//===================================
void loop()
{
  // send messages to GW
  // retrieve RSSI / SNR reports from incoming ACK
  send(msgRxRSSI.set(transportGetSignalReport(SR_RX_RSSI)));

  Serial.print("Receive RSSI: ");
  Serial.println(  RFM69_getReceivingRSSI ());

  //pr1:========== send vcc ==========
  float v = vcc.Read_Volts();
  Serial.print("VCC = ");
  Serial.print(v);
  Serial.println(" Volts");

  float p = vcc.Read_Perc(VccMin, VccMax);
  Serial.print("VCC = ");
  Serial.print(p);
  Serial.println(" %");
  send(msgVcc.set(v, 1));

  Serial.println("Enter in sleep time ...");
  //pr1:===== sleep =====
  LowPower.powerDown(SLEEP_8S, ADC_OFF, BOD_OFF); //COMPILATION ERROR  : libraries\LowPower-master\LowPower.cpp.o: In function `__vector_6':

  //sleep(SLEEP_TIME);                         //WORK BUT :  go from 25mA to 3.7mA (not µA)
  //gw.sleep(8000);             // MysensorsV1 :  3.7mA

}// FIN de LOOP

I have this error:

Arduino: 1.8.13 (Windows 10), Card: "ATmega328, Yes (UART0), EEPROM retained, 328P / 328PA, BOD 2.7V, LTO disabled, External 16 MHz "
libraries \ LowPower-master \ LowPower.cpp.o: In function `__vector_6 ':
D: \ Documents \ Arduino \ SKETCH \ libraries \ LowPower-master / LowPower.cpp: 1190: multiple definition of `__vector_6 '
sketch \ moteino_MySensors_vcc_sleep_pr3.ino.cpp.o: D: \ Documents \ Arduino \ SKETCH \ libraries \ MySensors / hal / architecture / AVR / MyHwAVR.cpp: 79: first defined here
collect2.exe: error: ld returned 1 exit status
exit status 1
Compilation error for the ATmega328 card

Someone to help me ?

[alexelite]

In MySensors/hal/architecture/AVR/MyHwAVR.cpp
find:

ISR (WDT_vect)
{
}

// Make it weak to allow local sketch implementation by changing it to

ISR(WDT_vect, __attribute__((weak)))
{
}

Make WDT_vect weak #717

Or you can do it like this Compile problem: multiple definition of `__vector_6'
Go to LowPower.cpp, find this lines

ISR (WDT_vect)
{
	// WDIE & WDIF is cleared in hardware upon entering this ISR
	wdt_disable();
}

and comment it

This last solution worked for me to compile with lowpower lib, but I wanted to use Timer2 on and that is incompatible with Mysensors for now.

[SuperNinja]

great thank you for your answer!