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what is use of SD0-3 io pins on esp32 ?

Posted: Tue Nov 17, 2020 11:24 am
by ht_main1
hi

What is Use of following IO pins? can they be used for normal GPIO operation?
SD0
SD1
SD2
SD3
CMD
CLK

SENSOR_VP
SENSOR_VN

I wish to know can these pins act as normal gpio? how can I use esp-idf 4.0 to configure these pin to act as GPIO?
In my project i used all the other GPIOs, and these are the only pin left and unconnected, can use any of these to drive LED

thanks & Regards
kesav

Re: what is use of SD0-3 io pins on esp32 ?

Posted: Tue Nov 17, 2020 11:52 am
by paras99
SD for connecting SD cards and CLK is clock signal

Re: what is use of SD0-3 io pins on esp32 ?

Posted: Tue Nov 17, 2020 12:21 pm
by ESP_Sprite
These also have a GPIO number, so technically you can address them like any other GPIO. However, note that normally, these pins are connected to the internal flash of the module/chip/devboard you have; in that case, reconfiguring them as a GPIO will likely crash your program. Check the datasheet of whatever you're using for more info. (Note that with recent ESP-IDF versions, you can actually also use some of these pins as a SPI master bus, but that's somewhat advanced and not always good to do.)

Re: what is use of SD0-3 io pins on esp32 ?

Posted: Tue Nov 17, 2020 12:32 pm
by ht_main1
ESP_Sprite wrote:
Tue Nov 17, 2020 12:21 pm
These also have a GPIO number, so technically you can address them like any other GPIO. However, note that normally, these pins are connected to the internal flash of the module/chip/devboard you have; in that case, reconfiguring them as a GPIO will likely crash your program. Check the datasheet of whatever you're using for more info. (Note that with recent ESP-IDF versions, you can actually also use some of these pins as a SPI master bus, but that's somewhat advanced and not always good to do.)
Hi Sprite

Thanks for reply and your valuable time,

SO these pins are non usable, i don't want to crash code, can I use either of
SENSOR_VP
SENSOR_VN

pin for GPIO functioning to drive LED?

are these 2 pins dedicated or can be usedas normal gpio also?
when we use ethernet most of the GPIO are taken up, I feel ESP should introduce IC with more GPIO like 64 pin package or 48 pin package so the consumer can pick depending on needs.

Re: what is use of SD0-3 io pins on esp32 ?

Posted: Tue Nov 17, 2020 1:50 pm
by felmue
Hello ht_main1

SENSOR_VP and SENSOR_VN are inputs only. So no, they cannot be used to drive an LED.

Please see Pin Definition here: https://www.espressif.com/sites/default ... eet_en.pdf

Thanks
Felix