I2C-RPT

Features

• I2C Hub / Repeater / Replicator / Multiplexer / De-multiplexer
• Four I2C Ports
• Host port Controlled via I2C
• PCA9544A IC Multiple vendors
• I2C Address fixed at 0x70
• 3.3V or 5V host operation
• 3.3V or 5V slave ports operation
• Voltage translation between the ports
• Example: A Raspberry PI which runs 3.3V can control an I2C device which runs at 5V
• Interrupt line on each channel and host
• 100KHz/400KHz operation
• On-board termination resistors
• 49x49mm form factor
• 4 solid 4-40 mounting holes
• Arduino driver and example code
• Raspberry Pi example code

Headers

• Install jumper to power the particular I2C interface from the card (Voltage matches J5 voltage
• Remove Jumper to the particular I2C interface from external interface (3.3V or 5V)
• Jumpers
  • H1 = I2C #0 Power
  • H2 = I2C #1 Power
  • H3 = I2C #2 Power
  • H4 = I2C #3 Power

Connectors

J1-J4 - I2C Slave ports

• Ports
  • J1 = I2C Port #0
  • J2 = I2C Port #1
  • J3 = I2C Port #2
  • J4 = I2C Port #3
• Pinout

1. GND
2. VCC (If Hx is installed, card powers this pin)
3. SDA
4. SCL
5. INT*

J5 - I2C to/from Host port

• Power comes in this connector
  • Voltage matches signal levels
  • 2.2K Ohm terminated
  • I2C address is fixed at 0x70

1. GND (G)
2. VCC (V) - Power into the card
3. SDA (D)
4. SCL (C)
5. INT* (I) - Interrupt (active low)

Drivers/Example Code

• GitHub Repo - Arduino Driver code
• Github Repo - Example code

Schematic

• Schematic

Testing

Test Station Hardware

• Arduino Based Test Station
  • Built in I2C mux on BLACK-PILL-HUB is set to offset=0x1 so it does not conflict with I2C address of UUT
• Uses 4x of I2CIO-8 cards
• Unit Under Test (UUT)
  • I2C address offset = 0x0
  • UUT J5 connects directly to I2C port (J7) on the BLACK-PILL-HUB
  • Install H1-H4 shunts
    • Powers I2CIO-8 cards from UUT

Test Station Software

• ODAS Tester Github Repo

Test Procedure

• Connect I2C

Assembly Sheet

• I2C-RPT-01 Assembly Sheet