Expander

ESP32 Open IoT and IIoT Gateways (P01 & P02)

The female goldpin connector allows easy access to different signals. It might be useful during analysis of the board.

GPI38 - general purpose input pin, connected directly to the MCU (might work only as an input pin)
3V3 - 3.3 V voltage
I2C_SCL and I2C_SDA - main lines of the I2C interface
GND - ground
NC - not connected
FGC - frame ground connection
BUT_EXT - switch test line ('1' is set by default)
Q2 - Q2 pin of the shift register
STCP - storage register clock input
SHCP - shift register clock input
Q7S - serial data output pin of shift register
CHIP_PU - chip power up signal ('1' - enables the chip)