SAFETY Signal on LTC6803 GPIO2 about diebiems HOT 2 OPEN

This is a system to disable the out and input when the watchdog triggers of the LTC (the LTC resets also its GPIO on WDT overflow). I use an GPIO on the LTC because over SPI I tell the LTC to pull the wire low (low being the charge / discharge are allowed to become high). So this is exactly as you have understood it operates.

The drawback of using the WDT is that it works the other way around, and you dont have a clear understanding of why the pin is asserted (any communication that is valid will reset the WDT if I recall correctly), where in the GPIO approach you have the uC deliberately ask the pin to go low.

( I actually first build it with the use of the WDT pin, but then moved to using the GPIO because of the added features described )

from diebiems.

This is a system to disable the out and input when the watchdog triggers of the LTC (the LTC resets also its GPIO on WDT overflow). I use an GPIO on the LTC because over SPI I tell the LTC to pull the wire low (low being the charge / discharge are allowed to become high). So this is exactly as you have understood it operates.

The drawback of using the WDT is that it works the other way around, and you dont have a clear understanding of why the pin is asserted (any communication that is valid will reset the WDT if I recall correctly), where in the GPIO approach you have the uC deliberately ask the pin to go low.

( I actually first build it with the use of the WDT pin, but then moved to using the GPIO because of the added features described )

That clearly makes sense to me! You are right - any valid communication will reset the WDT!
Thank you for your explanation!
I will use GPIO2. Because i don't have space for the SD card i will connect the WDT pin to the uC.
The ISL Interrupt signal is open drain, so i will connect it over 0R to the Safety signal.
So the ISL can also disable the charge and discharge FETs.
I think this will add another good safety feature to the device, because after the ISL is successfully configured, the software can stuck and overcurrent over- and undervoltage cutoff is still possible by hardware.

Another short question:
Is there a UART left on the STM? I plan to implement a connector for a serial bluetooth interface module like the cheap HC05, because the SPI wireless module is not available in germany :/
Could the mobile app of the BMS tool use this bluetooth connection or is connection only possible with your implemented wireless module?
I think this should work!?

from diebiems.