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ESP32-CAM Problem with not enough pins

Posted: Thu Nov 14, 2019 9:35 pm
by zdyboo
Hi, i am using this module with active camera and sd-card reader and i need 2 pins to software i2c to connect modules.
I added lines in SD_MMC.cpp

Code: Select all

slot_config.width = 1
host.flags = SDMMC_HOST_FLAG_1BIT; 
I try to use many combination of pins for example 13,16; 13,12; and more...
Anything dont work. According to this thread : viewtopic.php?t=11703, i have free pins 13,12 and 4 but 4 - it is flash led, 12 - if is use it, esp32 cant boot, the same o 16 pin - all time reboot. What i have to do to change these pins to I2C?

Re: ESP32-CAM Problem with not enough pins

Posted: Mon Dec 02, 2019 7:23 pm
by wattexi
I have the same problem, I need 2 pins free ... did you succeed and if so how?

Re: ESP32-CAM Problem with not enough pins

Posted: Tue Dec 03, 2019 5:34 am
by chegewara ... -Selection

When you read this you can see that pin 12 cant be connected to VCC (in your case, from your issue description):
If driven High, flash voltage (VDD_SDIO) is 1.8V not default 3.3V. Has internal pull-down, so unconnected = Low = 3.3V. May prevent flashing and/or booting if 3.3V flash is used and this pin is pulled high, causing the flash to brownout. See the ESP32 datasheet for more details.
but I2C requires SDA and SCL to be pullup.
There is solution for this, but its not easy. When you burn efuse then esp32 wont read pin 12 on restart: ... e-vdd_sdio

Of course you have to know what you are doing burning efuse because you may brick your device.

Re: ESP32-CAM Problem with not enough pins

Posted: Wed Dec 04, 2019 7:39 pm
by wattexi
thanks for your answer i'm looking at that