ESP32-I2C-HUB

Feature

• ESP32 breakout board
  • Requires specific version of ESP32 board
• GVS (Ground, Voltage, Signal) for all ESP32 pins
• 4-channel I2C Hub
  • TCA9544 - 4-Channel I2C and SMBus Multiplexer With Interrupt Logic
  • Isolated I2C channels
  • Interrupt for each I2C channel
  • I2C Channels can be independently powered with 3.3V or 5V
  • Jumper selectable I2C base address
• GVS (Ground, Voltage, Signal) for all ESP32 pins
• FTDI header
• SPI bus header
• 5V power source selection/distribution
  • 5V sources - USB, 5mm terminal block, DC jack
• On-board 3.3V power regulator (doesn't stress the ESP32 regulator)
• 95x95mm ODAS form factor
• 6-32 mounting holes

ESP-32 Module

• Board details
• On board Blue LED = Arduino Pin 2

Schematic

• ESP32-I2C-HUB Schematic
• ESP32-WROOM-32 Darasheet

Connectors

H1 - 3.3V from on-board regulator Header

• Install jumper

• Alternate for 3.3V power is to install S to V jumper at 3.3V header position (bottom right)
  • H1 should not be installed for that case

H2 - 5V SRC Header

• 2x3 header
• Care must be taken to install the correct jumpers
• USB jumper sends out 5V when a USB cable is connected to the ESP32 module
• USB jumper sends 5V into the ESP32 module when there is no USB cable connected to the ESP32 module

Power from USB on ESP32 module

• Do not install FTDI jumper
• Do not install DCJ jumper
• Install USB jumper

Power from 5V jack

• Do not install FTDI jumper
• Install DCJ jumper
• Install USB jumper

Power from FTDI

• Unstall FTDI jumper
• Do not install DCJ jumper
• Install USB jumper

J2 - FTDI

J3 - I2C Mux Base Address Select Jumpers

• A0-A2
  • Install for 0
  • Remove for 1

J7 - I2C Interface

• Also goes to the I2C Hub chip

1. INT* (GPIO5)
2. SCL
3. SDA
4. VCC
5. GND

J4, J5, J6, J8 - I2C Power Select (Ports #0-#3)

• Selects 3.3V or 5V on I2C
• 1-2 = 3.3V
• 2-3 = 5V

J9, J10, J11, J12 - I2C interfaces #0-#3

1. GND
2. VCC
3. SDA
4. SCL
5. INT*

P1 - 5V Power

• 2x8 pin header

P8 - SPIbus connector

1. MISO
2. 3.3V
3. SCK
4. MOSI
5. n/c
6. GND

Left GVS connector

• Gnd/3.3V/Signal

1. EN (Pull low to shut off 3.3V reg)
2. VP/P36
3. VN/P39
4. P34/P34
5. P35/A7
6. P32/A4
7. P33/A5
8. P25/A8
9. P26/A9
10. P27/SCL
11. P14/SD_CLK
12. P12/SD_D2
13. P13/SD_D3
14. VUSB

Right GVS connector

• Gnd/3.3V/Signal

1. P23/MOSI
2. SCL/RTS1
3. P1/TX
4. I3/RX
5. P21/SDA
6. P19/CTS0
7. P18/SCK
8. P5
9. P17/TX2
10. P16/RX2
11. P4/SD_D1
12. P2/SD_D0
13. P15/SD_CMD
14. 3.3V

Software Support

• GitHub repo
  • Examples
  • Libraries
• FreeRTOS
• Esp32 DevKit v1

Assembly Sheet

• ESP32-I2C-HUB Assembly Sheet