I2C-RPT-08
Contents
Features
- I2C Hub / Repeater / Replicator / Multiplexer / De-multiplexer / Switch
- PCA9548A Datasheet
- Eight I2C Ports
- 100KHz/400KHz operation
- Host port
- Controlled via I2C
- 3.3V or 5V host operation
- Can power slave cards if they are at the same voltage
- 3.3V or 5V slave ports operation
- Removable jumper(s) to supply power from slave
- Voltage translation between the ports
- Ex: a Raspberry Pi which runs 3.3V can control I2C devices which run at 5V
- On-board 2.2K termination resistors
- 49x49mm form factor
- 4 solid 4-40 mounting holes
Connectors
- The slave I2C connectors are (4) 2x6 right angle 0.1" pitch headers
- Two ports per 2x6 connector
- Two of the pins are for power to or from the I2C connector
- The other four pins are for the I2C interface
H1-H8 - Power to/from I2C Connectors
- Install shunt to power the I2C slave card from the I2C-RPT-08 Card
- Default factory ships as installed to power external I2C interfaces from the card
Host I2C Connection
- GND (GND pin marked)
- 3.3V or 5V VCC
- SDA
- SCL
Slave I2C Connections (x8)
- GND
- 3.3V or 5V VCC (Power Out - if jumper 1-2 installed, Power in - if jumper 1-2 is not installed)
- SDA
- SCL (Board marked with SCK)
Jumpers
A0-A2 - Multiplexer I2C Base Address
- Install for Ax = 0 (factory default address = 0)
- Remove for Ax = 1
Schematic
Drivers/Example Code
- Github repo - Driver code
- Github repo - Example code
Programming Note
- The mux chip allows multiple or single I2C ports to be written at the same time
- To only enable one port at a time make sure you disable a channel after use or disable last channel used before enabling new channel
Testing
- Arduino Based Test Station
- 9600 baud, no hardware handshake
- Uses 8x of I2CIO-8 cards
- On UUT
- Install jumpers into A0-A2
- I2C address offset = 0x0
- BLUE-PILL-HUB is set to offset=0x1 so it does not conflict
- Install jumpers into A0-A2
- Connect directly to I2C port on the BLUE-PILL-HUB
- ODAS Tester Github Repo
Issues
- Silkscreen shows SCK, should be SCL
