5.2 KiB
MAX14661
Arduino library for MAX14661 multiplexer with I2C interface.
Description
The MAX14661 multiplexer is a 16x2 channel multiplexer. It has 2 lines A and B which can be connected up to 16 A lines and 16 B lines.
The device can be controlled by SPI or I2C. This library implements only an I2C interface
The I2C address can be adjusted by 2 address lines A0 and A1. Addresses go from 0x4C (76) .. 0x4F (79). See table 3 datasheet.
Interface
The library provides 3 kinds of interfaces. Mixing these interfaces is allowed but definitely not advised as especially the PAIR interface assumes that A and B selections are kept in sync.
So depending on your application choose the interface you want to use.
Constructor
- MAX14661(deviceAddress, TwoWire *wire = &Wire) Constructor with device address, and optional the Wire interface as parameter.
- bool begin() initializes the wire interface
- bool begin(sda, scl) idem, for the ESP32 where one can choose the I2C pins.
- bool isConnected() checks if the address is visible on the I2C bus.
PAIR interface
The functions in this interface part all work symmetrical on the A and B line. They are managed as a PAIR. So this is ideal e.g. to multiplex an I2C bus or a Serial TX/RX pair line.
The interface allows to have multiple lines A/B open in parallel.
// open ==> connect
- bool openChannel(uint8_t channel) connects A/B to output channel
- bool closeChannel(uint8_t channel) disconnects channel from A/B
- bool isOpenChannel(uint8_t channel) returns true if connected to A/B
- void openAllChannels() connects all channels
- void closeAllChannels() disconnects all channels
- void setChannels(uint16_t mask) connect multiple channels with a bit mask.
- uint16_t getChannels() returns a bit mask of the channels connected.
SHADOW interface
experimental - to be tested.
The SHADOW interface allows one to prepare which channels should be selected and activate them all at once.
- bool shadowClear() clears all shadow registers.
- void activateShadow() write all shadow registers to the direction registers of A and B at once.
prepare multiple channels at once. This is way faster than per channel.
- bool setShadowChannelMaskA(uint16_t mask) write all channels at once.
- uint16_t getShadowChannelMaskA() read shadow registers
- bool setShadowChannelMaskB(uint16_t mask) write all channels at once.
- uint16_t getShadowChannelMaskB() read shadow registers
prepare per channel
- bool isOpenShadowChannelA(uint8_t channel) read status of specific channel in shadow registers.
- void openShadowChannelA(uint8_t channel) prepare a specific channel to open
- void closeShadowChannelA(uint8_t channel) prepare a specific channel to close
- bool isOpenShadowChannelB(uint8_t channel) read status of specific channel in shadow registers.
- void openShadowChannelB(uint8_t channel) prepare a specific channel to open.
- void closeShadowChannelB(uint8_t channel) prepare a specific channel to close.
MUX interface
The MUX interface allows one channel to be open at a time.
- void MUXA(uint8_t channel) if channel < 16 only that channel will be selected. All other values will select no channel.
- uint8_t getMUXA() returns the selected channel. 255 means none selected.
- void MUXB(uint8_t channel) if channel < 16 only that channel will be selected. All other values will select no channel.
- uint8_t getMUXB() returns the selected channel. 255 means none selected.
FULL CONTROL interface
full control per channel, any combination is possible. Use with care as these can interfere e.g. with the PAIR interface. All functions return false if channel > 15.
- bool openA(uint8_t channel) idem
- bool openB(uint8_t channel) idem
- bool closeA(uint8_t channel) idem
- bool closeB(uint8_t channel) idem
LOW LEVEL CONTROL interface
Check datasheet for these values of the registers.
- uint8_t readRegister(uint8_t reg) read low level device register.
- int writeRegister(uint8_t reg, uint8_t value) write value to device register.
Misc
- int lastError() returns the last error, limited to I2C for now.
Error codes
to be elaborated
Future
- test behaviour
- test I2C speed.
- measure performance
- optimize low level bit set/clr/get read/write 2bytes at once.
- write unit tests.
- error handling
- improve documentation
- initial values parameter for begin()?
Operation
See examples