ESP32-POE R32 pull up for EN

Started by zigzag_tr, December 01, 2020, 11:09:25 am

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zigzag_tr

i develope fw. with usb port for programing and design pcb for use poe and connection over ethernet. in last step, i use power from poe and have a problem that esp32 core not start to operation on my esp32-poe rev.E . but when i switch to use esp32-poe rev.C, it seem to not found this problem.  so i checked on schematic and found pull-up resistor on R32 changed from 1k ( rev.c ) to 10k ( rev.E) and i try to changed this resistor back to 1k (on rev. E ) and it's look ok when i powered board by poe.  i want to ask for this solution is right? and any condition or problem which you change this resistor value.

LubOlimex

Thanks for feedback. Your fix is ok. There is no problem for R32 to be either 1k or 10k. Our tests and some feedback for customers showed that 10k is the better value but we might re-consider if other people encounter similar start-up prolems with revision E boards.
Technical support and documentation manager at Olimex

zigzag_tr

Update :  From my design last time, i design base on esp32-poe rev.c and i have this problem so i was added 10uf capacitor on my board. But new rev.e,Olimex buit-in 1uf cap. from store so i have not to solder this capacitor on my board . now when power the board , it always reset and start to operate.  :D