December 02, 2021, 12:11:54 am

I2C with ESP32-POE

Started by danski, November 28, 2020, 10:26:14 pm

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danski

I'm using the ESP32-POE with ethernet, both for power and communication. I'm struggling a bit for free I/O pins, so taking the Olimex advice:

Quote from: LubOlimex on June 24, 2019, 11:24:16 amIf you need more GPIO pins consider either using additional GPIO expander board over I2C/SPI/UART

I bought an MCP23008. But I'm a bit confused which pins I should use it with. This chap seems to have used the ESP32-POE-ISO with both ethernet and I2C, but when I look at the I2C pins, 16 seems to be used by both EMAC_CLK_OUT_180 and EMAC_RX_ER so I don't really understand how that's working successfully for him.

Guidance would be really appreciated, thank you!

LubOlimex

Technical support and documentation manager at Olimex

danski

Quote from: LubOlimex on November 30, 2020, 09:48:01 amPins 13 and 16 are alright.

Thank you I'm confused how pin 16 is usable when it is used by both emac_clk_out_180 AND emac_rx_er? Just don't understand enough! :-)

LubOlimex

I think you are confusing ESP32 pin #16 and GPIO #16 which is ESP32 pin #27.

The Arduino code doesn't care about ESP32 pin #; only about GPIO#.
Technical support and documentation manager at Olimex