Usable PINs on ESP32 Wroom32

SAYEDBAQER
Posts: 3
Joined: Thu Sep 28, 2017 12:44 pm

Usable PINs on ESP32 Wroom32

Postby SAYEDBAQER » Thu Sep 28, 2017 12:47 pm

Hi,
any body can help me with which pins is available to use as GPIO?
which one pins is used by ESP flash?
which SPI pins can be used as SPI for sd card? HSPI or VSPI? if one of them in used the others can be used as GPIO?
which GPIO remaining will be available as GPIO?
Best regards,
Sayed

SAYEDBAQER
Posts: 3
Joined: Thu Sep 28, 2017 12:44 pm

Re: Usable PINs on ESP32 Wroom32

Postby SAYEDBAQER » Thu Sep 28, 2017 2:30 pm

my requirement is 9 output, 7 input for push button, 3 input for sensors, Sd card
i am switching from ESP8266 Nodemcu 12E, since this ESP32 has more GPIO
i hope there is chance to get these pins to be enough
best regards,
Sayed

ESP_Sprite
Posts: 9761
Joined: Thu Nov 26, 2015 4:08 am

Re: Usable PINs on ESP32 Wroom32

Postby ESP_Sprite » Fri Sep 29, 2017 2:10 am

The datasheet should show you where the flash is connected. The esp32 datasheet can then help you figure out the GPIO numbers for that. Wrt the SPI pins for an SD-card: while for fastest performance, you want to connect that to the pins as indicated in the datasheet as VSPI*/HSPI*, due to the chip having a GPIO mux you can route those signals to any GPIO. Do take care when using GPIO34-39; these are input only and can't have internal pull-ups or -downs, as can be seen in the table on the last page of the datasheet. Also make sure that the strapping pins (GPIO0 and GPIO2) have the right signal level on bootup.

On the WROOM32, specifically: all the pins in use by the flash are on the bottom of the module (specifically, SD0-3, CLK, CMD). That leaves you 24 pins (4 input-only) to connect stuff to.

SAYEDBAQER
Posts: 3
Joined: Thu Sep 28, 2017 12:44 pm

Re: Usable PINs on ESP32 Wroom32

Postby SAYEDBAQER » Fri Sep 29, 2017 10:17 am

thanks very much,
so i will use pins GPIO 0/2/36/39/34/35/32 as input push button normally open with pullup resistor to 3V3
and GPIO 4/16/17 for sensor input and GPIO 33/25/26/27/14/12/13/15 as output
is it ok or use in this way can cause issue on operating or damage to the board?

best regards,
Sayed

ESP_Sprite
Posts: 9761
Joined: Thu Nov 26, 2015 4:08 am

Re: Usable PINs on ESP32 Wroom32

Postby ESP_Sprite » Fri Sep 29, 2017 12:35 pm

You can do that, but be aware that pressing the buttons connected to GPIO0 and 2 can make the ESP32 boot in the wrong mode when held at power-up.

Who is online

Users browsing this forum: No registered users and 109 guests