Is brownout detection usable now?

[urbanze]

What is the maximum value can I get to trigger BOD? In menuconfig, maximum is ~2.7V (7<<bit) == (10000000), but whats happen if write (11111111)? I would like to get ~3V, this is possible?

[WiFive]

It is a 3 bit value so 7 is max

[urbanze]

It is a 3 bit value so 7 is max

Oh sorry, bodwait_reg is larger. My mistake. But if 7 is max, I should 3V is impossible... Thanks.


I testing my own isr to write some data in flash in case BOD trigger, but I think that nvs API is little slow. What API can I use to write in flash with velocity focus?

[ESP_igrr]

When brownout is detected, it is very likely that reliable flash writes are already impossible (unless you have a 1.8V capable part). In fact, in many cases it is the flash chip that browns out first.

[urbanze]

When brownout is detected, it is very likely that reliable flash writes are already impossible (unless you have a 1.8V capable part). In fact, in many cases it is the flash chip that browns out first.

Can you say any "internal" method to write data to avoid lost data in ram?

[ESP_igrr]

Possibly RTC memory via RTC_NOINIT_ATTR, but it may be lost if the supply voltage drops below about 1V.

[urbanze]

Possibly RTC memory via RTC_NOINIT_ATTR, but it may be lost if the supply voltage drops below about 1V.

Ya, this is my last ideia but with power off, all ram is lost. I will try tomorrow.

[urbanze]

I testing velocity of BOD comparator but with ~2.7V +- 0.05V make little hard to find specific latency.

What's the latency of BOD since threshold AND isr? In some PIC's is ~500ns + 2 cycles + X cycles to handle isr... And in esp32?