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OLIMEX / ESP32-POE-ISO

ESP32 Power Over Ethernet board with 3000VDC Galvanic insulation
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Ethernet Connection as esp sleep wake source #4

Closed lucaelin closed 2 years ago

lucaelin commented 3 years ago

Is it possible to use the ethernet connection as a wake source for the esp32 deep sleep? I couldn't find any documentation for this and the ethernet RX and TX are directly connected to the LAN8710A with no way to detect the switches auto-negotiation signals using the esp. AFAIK using the external power pin would work only if the switch supplies PoE... Passing wires from the jacks RX lines to the GPIOs would work and not violate the galvanic isolation, right? Or does the LAN8710A provide another way to detect a connection without being powered? Thanks in advance!

DanKoloff commented 3 years ago

Probably any GPIO can be used as external source for wake up from deep sleep, but we haven't tested it. Please check what is written here:

https://docs.espressif.com/projects/esp-idf/en/latest/esp32/api-reference/system/sleep_modes.html

Look for "ext0" and "ext1". You can probably set the Ethernet pins for RTC IO function (GPIO25=RTC_GPIO6; GPIO27=RTC_GPIO7) to the pins of the Ethernet, so they cane used for deep sleep wake up.

Also here:

https://lastminuteengineers.com/esp32-deep-sleep-wakeup-sources/

Additionally, consider light sleep mode that would leave more peripherals enabled. The difference in current consumption is probably 200uA for deep sleep and 900uA for light sleep, so in most cases light sleep is good enough.

LAN8710A has such pin but we haven't routed it, so it is unavailable. If you look into LAN8710A's datasheet look for "nINT"

lucaelin commented 2 years ago

I am sorry I didn't get back to this... I approached this issue several times looking deep into the reference that you provided, but I still was not able to solve this. From my understanding, once that esp is in sleep mode, the ethernet looses its clock to transfer any data to the esp. I've tried multiple things to get around it, but no solution would ultimately wake the esp. In short I'm still stuck with this issue, but I am also a little out of my comfort zone here.

DanKoloff commented 2 years ago

By default this is the expected outcome since Ethernet and WIFI are disabled in all power down modes. That is why you need to "hack" other ways to wake up, aka use signals arriving at Ethernet connector and route them to ext0 and ext2 that can be used as wake up source.

My advice is to first place a button on ext0 or ext1 pin then test it as wake up source, then figure how to do it with the Ethernet connector.

The wake up sources can be:

-Timer -Touch pad -External wakeup(ext0 & ext1)