Peripherals

Simplified Block Diagram
ESP32 Open IoT and IIoT Gateways (P01 & P02) 

 

 Optional elements are marked with the dashed lines.

RGB LED
ESP32 Open IoT and IIoT Gateways (P01 & P02) 

 

 RGB LED is controlled by SIPO shift register 74HC595BQ. 

 

 SHCP - shift register clock input 

 STCP - storage register clock input 

 DS - serial data input

Switch
ESP32 Open IoT and IIoT Gateways (P01 & P02) 

 

 The Open IoT Gateway P01 variant contains a tactile switch. The PCB has hardware pull-up designed into it so debouncing effect is eliminated. 

 If the switch is soldered to the PCB, make sure there is also a resistor R52 located on the bottom layer of the board.

RS232 and RS485
ESP32 Open IoT and IIoT Gateways (P01 & P02) 

 

 The gateway is equipped with 2 transceivers MAX481 that handle transmission in RS485 standard on each channel independently. Similar to RGB, each channel can be enabled by SIPO shift register 74HC595BQ. 

 To ensure transmission in RS232 standard there is also ST3232BTR IC which allows transmission on each channel independently.  

 It is possible to use only one pair of each interface at the same moment, because RS232 and RS485 use the same UART pins on the MCU.

Ethernet PHY
ESP32 Open IoT and IIoT Gateways (P01 & P02) 

 

 The Ethernet interface is provided by the IP101G physical layer. There is also an external board with RJ45 socket which ensures wired connection to the network.

MicroUSB
ESP32 Open IoT and IIoT Gateways (P01 & P02) 

 

 MicroUSB ensures access straight to UART interface (UART0). The Open IoT Gateway does not have inbuild FTDI converter so an external USB to UART FTDI converter is needed to run a serial port monitor on a PC.

I2C EEPROM
ESP32 Open IoT and IIoT Gateways (P01 & P02)

Antenna
ESP32 Open IoT and IIoT Gateways (P01 & P02) 

 

 The Open IoT and IIoT Gateway P02 variant contains SMA connector for a 2.4G antenna.

QSPI Flash
ESP32 Open IoT and IIoT Gateways (P01 & P02)

QSPI RAM
ESP32 Open IoT and IIoT Gateways (P01 & P02)

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)

I2C Sensors
ESP32 Open IoT and IIoT Gateways (P01 & P02) 

 

 

 LSM6DS33 - 3D accelerometer and 3D gyroscope 

 LIS3DH - 3-axis "nano" accelerometer 

 HTS221 - capacitive digital sensor for relative humidity and temperature measurements 

 SI7006-A20 / SI7020-A20 - humidity and temperature sensor 

 Secure element