Component: I2C Multiplexer (TCA9548A) (Comms: System)

Author	MatrixTSL
Version	1.0
Category	Comms: System

I2C Multiplexer (TCA9548A) component

An I2C multiplexing IC allowing up to 8 different I2C busses to be connected to a single I2C channel on your target microcontroller.

Detailed description

No detailed description exists yet for this component

Examples

Here we have a simple example showing how to use the multiplexer to connect multiple of the same I2C sensor IC to the microcontroller.

The multiplexer IC is connected directly to the microcontroller I2C pins and up to 8 temp/humidity sensors are connected to the CH0-CH7 I2C pins of the multiplexer.

I2C Multiplex Example

Downloadable macro reference

	SelectChannel
Selects a single output channel to multiplex the I2C output to (0-7).
- BYTE	Channel
Range: 0-7
- VOID	Return

	SetChannelMask
Allows a user determined number of channels to be connected to the I2C bus.
- BYTE	Mask
Range: 0-255 / Bit0=CH0 EN / Bit1 = CH1 EN etc
- VOID	Return

	Initialise
Startup the I2C bus ready for communications.
- VOID	Return

	Transaction_Read
Attempt to read Length number of bytes from the I2C slave to the given Buffer. Ensure that the Buffer is large enough. Returns number of bytes read, caller should check that this matches requested Length
- BYTE	Buffer
Buffer to store the incoming byte data
- UINT	Length
Number of bytes to read
- UINT	Return

	Start
Outputs a start condition onto the I²C bus.
- VOID	Return

	Transaction_Initialise
Initialise the I2C interface to communicate with a Slave device at Address Returns 0 on fail, 1 on success
- BYTE	Address
7-bit I2C Address without the shift for the R/W bit
- BYTE	Return

	Initialise
Enables the I²C hardware and performs some initialization. Should be called at the start of the program or at least before any of the other I²C functions are called.
- VOID	Return

	Initialise
Initialise the sensor configuration as set by the component properties. Sets the default intigration time and gain as well as enable the sensor.
- VOID	Return

Property reference

	Properties
	Address Bits
	Stop Delay
On older microcontroller devices there is a potential for the I2C hardware channel to lock up if there is not a 10ms delay between an I2C stop event and the next I2C start event. Most modern microcontrollers will not have a problem so this property can be disabled to speed up the I2C communications.
	Baud Select
Baud rate option selector
	Baud Rate
Baud rate to be used
	Scope Traces
Selects if the component pin connections are automatically generated on the data recorder window or not. Yes: Automatically add the component pins to a group on the data recorder which will reflect the sim data during simultion. No: Do not show the pin signals on the data recorder window.
	Console Data
Selects if the console data is automatically generated or not
	Injector
Specifies the injector component on the panel to interact with to provide comms simulation.
	Connections
	Channel
Channel selection
	SDA
Pin used for SDA (data signal)
	SCL
Pin used for SCL (clock signal)
	Simulations
	Simulate Comms