ESP32-POE-ISO and ARM-USB-TINY-H

[jb1]

Hello,

is the JTAG interface available on the ESP32-POE-ISO?

In the schematic it looks like that the GPIO12 (TDI) pin is not available?

Thanks for the info.

[LubOlimex]

You can't easily use the JTAG with ESP32-PoE-ISO since one of the signals is not routed to either the GPIO headers, nor to the UEXT connector. Accessing it would be impractical. It is similar to ESP32-PoE, i provided more details for ESP32-PoE here: https://www.olimex.com/forum/index.php?topic=6774.msg26426#msg26426

[jb1]

Thank you for your fast reply.

So tapping the JTAG debugger straight to pin 14 (GPIO12) and removing T1 while bridging the connection it controlls to have the ethernet active all the time is a viable solution?

This mod would be only for the development process so practicality is not really a concern to us.

Thank you for the info!

Regards.

[LubOlimex]

Yes, this is a solid option for your case but consider that removing the transistor might hinder the Ethernet operation permanently, since the ESP32 MUST start before the Ethernet chip. See GPIO12/PHY_PWR is not really optional signal when sourcing the Ethernet clock FROM the ESP32 chip - PHY reset pin is recommended by espressif and it is used actively in all software. Read more about it in the official espressif documentation And a shorter notice here:

https://sautter.com/blog/ethernet-on-esp32-using-lan8720/