What pins can really be used in ESP32-POE-ISO

Started by alborz, June 24, 2019, 08:12:20 am

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alborz

I am working on a board using ESP32-POE-ISO and I am trying to drive as many addressable LEDs as possible, for this I would like to use as many pins as I possibly can.
(I don't plan to use the SD-card, but I would like to be able to print via serial)

So far I have failed to use the following pin to write to LEDs.
GPIO0
GPIO1/U0TXD
GPIO2/HS2_DATA0


Can someone confirm these pins can not be used for anything useful.
GPIO0 is used for bootstrapping.
GPIO1/U0TXD is connected to USB/UART.
GPIO2/HS2_DATA0 is connected to SD Module.

This only leave me the output pins, GPIO3, 4 and 5 (the pins above 30 are not suited to drive addressable LEDs)

LubOlimex

The bootstrap pins can be used after the boot process ends. LEDs attached to GPIOs can't affect the bootstrap levels so no problems to use them. If you don't have micro SD card, then probably you can use the following:

GPI00, GPIO1, GPIO2, GPIO3, GPIO4, GPIO5, GPIO13, GPIO14, GPIO15, GPIO16, GPIO32, and GPIO33

Maybe avoid using GPIO0 and GPIO1 if you wish to clear the USB lines (maybe for debugging purposes). But I think that there are no problems to also use GPIO0 and GPIO1, since they are freed after programming. Depends on your project

The ESP32 doesn't have a lot of pins and the Ethernet uses a lot of pins.  If you need more GPIO pins consider either using additional GPIO expander board over I2C/SPI/UART, or another ESP32-PoE-ISO board.
Technical support and documentation manager at Olimex

mzeuner

July 24, 2019, 03:36:36 pm #2 Last Edit: July 24, 2019, 04:16:26 pm by mzeuner
I have a similar question, that is how can I use SPI with the ESP32-POE-ISO?
I found this information regarding SPI on ESP32:

VSPI   MOSI GPIO 23   MISO GPIO 19   CLK GPIO 18   CS GPIO 5
HSPI   MOSI GPIO 13   MISO GPIO 12   CLK GPIO 14   CS GPIO 15
Quote from: LubOlimex on June 24, 2019, 11:24:16 am
...If you don't have micro SD card, then probably you can use the following:
GPI00, GPIO1, GPIO2, GPIO3, GPIO4, GPIO5, GPIO13, GPIO14, GPIO15, GPIO16, GPIO32, and GPIO33

This list is missing some of those pins so it seems neither VSPI or HSPI can be used?



EDIT
Okay I found out that you can freely reassign the SPI pins. Didn't know that. So my question is answered, but I'm gonna leave this here in case someone else runs into the same issue.