GY-63_MS5611/libraries/PCA9549

PCA9549

Arduino Library for PCA9549 I2C octal bus switch.

Description

Library for the PCA9549 and compatibles.

The library allows you to switch on/off 8 channels uniquely or simultaneously.

Warning The library is not tested yet.

The library caches the channels enabled, and if a channel is enabled, it will not be enabled again (low level) to optimize performance.

I2C

I2C address of the device itself is 0x70 .. 0x77.

Related

• https://github.com/RobTillaart/TCA9549 - strong interface and code similarity

Interface

#include "PCA9549.h"

Constructor

• PCA9549(const uint8_t deviceAddress, TwoWire *wire = &Wire) Constructor. deviceAddress = 0x70 .. 0x77, wire = Wire or WireN.
• bool begin(uint8_t mask = 0x00) set mask of channels to be enabled, default all disabled.
• bool isConnected() returns true if address of the multiplexer is found on I2C bus.

Channel functions

All "channel functions" return true on success.

• bool enableChannel(uint8_t channel) enables channel 0 .. 7 non-exclusive. Multiple channels can be enabled in parallel.
• bool disableChannel(uint8_t channel) disables channel 0 .. 7. Will not disable other channels.
• bool selectChannel(uint8_t channel) enables a single channel 0 .. 7 exclusive. All other channels will be disabled in the same call, so not before or after.
• bool isEnabled(uint8_t channel) returns true if the channel is enabled.
• bool disableAllChannels() fast way to disable all.
• bool setChannelMask(uint8_t mask) enables 0 or more channels simultaneously with a bit mask.
• uint8_t getChannelMask() reads back the bit mask of the channels enabled.

Reset

• void setResetPin(uint8_t resetPin) sets the pin to reset the chip. (Not tested)
• void reset() trigger the reset pin.
• int getError() returns the last I2C error.

Forced IO

When forced IO is set all writes and read - getChannelMask() - will go to the device. If the flag is set to false it will cache the value of the channels enabled. This will result in more responsive / faster calls. Note that writes are only optimized if the channels are already set.

• void setForced(bool forced = false) set forced write, slower but more robust.
  • forced == false == fast mode (default).
  • forced == true == slower, robust mode.
• bool getForced() returns set flag.

Error Codes

Not implemented yet, preparation for future.

name	value	description
PCA9549_OK	00	no error

Future

Must

• improve documentation.

Should

• keep aligned with TCA9548 / PCA9548 library where meaningful.
• add examples e.g. real life scenarios.
• test with hardware

Could

• improve error handling.

Wont

Support

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Thank you,