Incorrect clock selection

[EchterAgo]

The change in #14 is not correct. The previous code was using ETH_CLOCK_GPIO0_IN which is the default. Changing it to ETH_CLOCK_GPIO17_OUT will leave the ESP MAC running off a different clock than the LAN8720, which still runs off the external oscillator.

Using ETH_CLOCK_GPIO17_OUT does initially seem to work but it causes periodic packet loss because the two oscillators are not in sync.

GPIO17 is routed to the TX LED / Pin, so you can see the LED glow faintly. It seems to me that ETH_CLOCK_GPIO0_IN matches the ESP-IDF example code in README.md.

[EchterAgo]

@ProgrammingJohn

[egnor]

What would you say the correct settings are?

[EchterAgo]

ETH.begin(ETH_PHY_LAN8720, 1, 23, 18, 16, ETH_CLOCK_GPIO0_IN)

or in the version of the ESP32 Arduino framework still in use by PlatformIO (< v3.0):

ETH.begin(1, 16, 23, 18, ETH_PHY_LAN8720, ETH_CLOCK_GPIO0_IN);

Alternatively you can use:

#define ETH_PHY_POWER 16
ETH.begin()

or:

pinMode(16, OUTPUT);
digitalWrite(16, HIGH);
ETH.begin()

[ProgrammingJohn]

Apologies with that oversight. Thank you for finding a correction. I simply ran with what worked after looking at some other documentation online but honestly didn't know the effect of the ETH_CLOCK_GPIO0_IN argument. I will switch back to IN within my code.

Regardless my main fix was the updated positional arguments for ETH.begin

Thanks again!

[EchterAgo]

Looks good, closing.