Watchdog timer clash with other libs using ISR(WDT_vect)

[systemofapwne]

When using this library in conjunction with any other library, which somehow seems to interact with watchdog timers, the compile fails.

`libraries\Low-Power-master\LowPower.cpp.o (symbol from plugin): In function 'LowPowerClass::idle(period_t, adc_t, timer2_t, timer1_t, timer0_t, spi_t, usart0_t, twi_t)':

(.text+0x0): multiple definition of '__vector_6'

libraries\Crypto\RNG.cpp.o (symbol from plugin):(.text+0x0): first defined here

collect2.exe: error: ld returned 1 exit status`

I narrowed it down to be a problem with calling ISR(WDT_vect) in multiple contexts.

This lib: https://github.com/rocketscream/Low-Power/blob/master/LowPower.cpp#L1131 libcrypto: https://github.com/rweather/arduinolibs/blob/master/libraries/Crypto/RNG.cpp#L228

Is the use of ISR(wdt_) necessary to work? (I guess so). If so, is there any way to avoid this clash?

[rocketscream]

Yes, the watchdog is used as a timer to wake the MCU up. I'm not sure whether you can avoid this because both are accessing the same resource here.

[systemofapwne]

For now, I disabled the WDT in the crypto-lib, which makes the RNG for my crypto-project basically useless (the WTD-jitter has been used to produce entropy for seeding the RNG). Can I safely disable the WDT in the low-power lib, if I only use SLEEP_FOREVER or will something else break?

Cheers

[rocketscream]

If you use SLEEP_FOREVER, the WDT code section won't be called. You could do that. Maybe an #ifdefwould help.

[systemofapwne]

Cool, thank you. Since I do not know any better solution right now, I will move into this direction. Thanks!