Usable IO pins in T-SIMCAM

[ojas-savarkar]

According to the below image from LILYGO website for T-SIMCAM, there are 4 IO pins broken out i.e. IO21, IO45, IO46, IO31. Out of which, the IO45 & IO46 are used for mPCIe_TX & mPCIe_RX respectively. IO21 is used for mPCIe_LED.

I need 2 IO pins free to attach an I2c based sensor. In that case, is it possible to use the IO31 and IO21 pins for SDA & SCL?

Thanks in advance!

[lewisxhe]

This board has no extra GPIO, GPIO31 is wrong, wrong silk screen and wrong picture. GPIO31 is the connection pin of ESP32 Flash and is unavailable.

[ojas-savarkar]

I have purchased this board, it is as shown in the picture. Please refer to the image below.

Do you think that I will be able to add an I2C based sensor by soldering SDA SCL wires to any unused pins? For. eg. the Microphone pins which will not be used in my case and also remapping these pins in the firmware.

[RogerParkinson]

FWIW I think you can't. 45 and 46 are used for TX and RX, 21 is used for the LED and the modem turns this on and off, so you can use 21 to tell if the modem has turned it on but you can't turn it on yourself, I think. 31 (silk screen) isn't GPIO31 it is SPICLK_N and is connected to PCIE_RST which is connected to the modem's SPICLK_N. It means all of those pins are used by the modem for something so you can't use them for something else without the modem messing it up. Of course if you aren't using a modem you can do what you want... except use a modem.