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 (https://community.home-assistant.io/t/working-ethernet-thermometer-using-the-olimex-esp-poe-iso-board/175371) 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!
Pins 13 and 16 are alright. Don't forget the GND. We have published examples of ESP32-POE with I2C modules at the Arduino software section here:
https://github.com/OLIMEX/ESP32-POE/tree/master/SOFTWARE/ARDUINO
MOD-BME280 uses I2C:
https://github.com/OLIMEX/ESP32-POE/blob/master/SOFTWARE/ARDUINO/ESP32_PoE_MOD_BME280/ESP32_PoE_MOD_BME280.ino
MOD-IO uses I2C:
https://github.com/OLIMEX/ESP32-POE/blob/master/SOFTWARE/ARDUINO/ESP32_PoE_WebServer_MOD_IO/ESP32_PoE_WebServer_MOD_IO.ino
there are few others there too.
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! :-)
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#.
Are you sure I'm confusing my pins??
(https://i.imgur.com/U2hfbBX.png)
Here the ESP32-POE clearly shows that GPIO pin 16 is used by both emac_clk_out_180 AND emac_rx_er?
Quote from: LubOlimex on November 30, 2020, 09:48:01 AMPin 13 [is] alright.
GPIO Pin 13 is pulled up to 3v??
This board sure is hard to work with! :-)
Better download and use the schematic export to track these. Here:
https://github.com/OLIMEX/ESP32-POE/blob/master/HARDWARE/ESP32-PoE-hardware-revision-K/ESP32-PoE_Rev_K.pdf
Yes, both GPI)16 and GPIO13 are pulled up. This is for I2C compatibility sake. You can pull them down or remove the resistor that connects them to 3.3V.