Unit MCP230XX

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Description


The Microchip MCP23008 and MCP23017 are 8 or 16 bit I/O expanders that provide GPIO pin control functions over an I2C connection.

The device can be represented in Ultibo as a standard GPIO device which is accessible via the GPIO unit functions. Because the MCP230XX is a chip that can be used and configured in multiple different scenarios this unit does not autocreate a GPIO device, instead you need to call the function MCP23008GPIOCreate or MCP23017GPIOCreate and pass an I2C device and address. The functions will create and return a GPIO device with the appropriate number of pins and other information for the specified chip, the returned devices will have been registered with the GPIO device unit and started ready for use.

Both devices also come in an SPI interface version, these are not currently supported by this unit.

Note: This unit does not currently implement the interrupt capabilities of the MCP230XX chips however it could be expanded to allow the interrupt pin to be connected to a GPIO pin on the SoC and use a trigger event from that to enable GPIOInputWait/GPIOInputEvent functions for the MCP230XX chips.

Constants


To be documented

Type definitions


To be documented

Public variables


To be documented

Function declarations



MCP230XX functions

function MCP23008GPIOCreate(I2C:PI2CDevice; Address:Word):PGPIODevice;
Description: Create, register and start a new MCP23008 GPIO device connected to the specified I2C device
I2C The I2C device this MCP23008 is connected to
Address The I2C address for this MCP23008
Return Pointer to the new GPIO device or nil on failure


function MCP23017GPIOCreate(I2C:PI2CDevice; Address:Word):PGPIODevice;
Description: Create, register and start a new MCP23017 GPIO device connected to the specified I2C device
I2C The I2C device this MCP23017 is connected to
Address The I2C address for this MCP23017
Return Pointer to the new GPIO device or nil on failure


function MCP230XXGPIODestroy(GPIO:PGPIODevice):LongWord;
Description: Stop, deregister and destroy an MCP230XX GPIO device created by this driver
GPIO The GPIO device to destroy
Return ERROR_SUCCESS if completed or another error code on failure


MCP230XX GPIO functions

function MCP230XXGPIOStart(GPIO:PGPIODevice):LongWord;
Description: Implementation of GPIODeviceStart API for MCP230XX
Note Not intended to be called directly by applications, use GPIODeviceStart instead


function MCP230XXGPIOStop(GPIO:PGPIODevice):LongWord; 
Description: Implementation of GPIODeviceStop API for MCP230XX
Note Not intended to be called directly by applications, use GPIODeviceStop instead


function MCP230XXGPIORead(GPIO:PGPIODevice; Reg:LongWord):LongWord;
Description: Implementation of GPIODeviceRead API for MCP230XX
Note Not intended to be called directly by applications, use GPIODeviceRead instead

Will read only a single register byte


procedure MCP230XXGPIOWrite(GPIO:PGPIODevice; Reg,Value:LongWord);
Description: Implementation of GPIODeviceWrite API for MCP230XX
Note Not intended to be called directly by applications, use GPIODeviceWrite instead

Will write only a single register byte


function MCP230XXGPIOInputGet(GPIO:PGPIODevice; Pin:LongWord):LongWord;
Description: Implementation of GPIODeviceInputGet API for MCP230XX
Note Not intended to be called directly by applications, use GPIODeviceInputGet instead


function MCP230XXGPIOOutputSet(GPIO:PGPIODevice; Pin,Level:LongWord):LongWord;
Description: Implementation of GPIODeviceOutputSet API for MCP230XX
Note Not intended to be called directly by applications, use GPIODeviceOutputSet instead


function MCP230XXGPIOPullGet(GPIO:PGPIODevice; Pin:LongWord):LongWord;
Description: Implementation of GPIODevicePullGet API for MCP230XX
Note Not intended to be called directly by applications, use GPIODevicePullGet instead


function MCP230XXGPIOPullSelect(GPIO:PGPIODevice; Pin,Mode:LongWord):LongWord;
Description: Implementation of GPIODevicePullSelect API for MCP230XX
Note Not intended to be called directly by applications, use GPIODevicePullSelect instead


function MCP230XXGPIOFunctionGet(GPIO:PGPIODevice; Pin:LongWord):LongWord;
Description: Implementation of GPIODeviceFunctionGet API for MCP230XX
Note Not intended to be called directly by applications, use GPIODeviceFunctionGet instead


function MCP230XXGPIOFunctionSelect(GPIO:PGPIODevice; Pin,Mode:LongWord):LongWord;
Description: Implementation of GPIODeviceFunctionSelect API for MCP230XX
Note Not intended to be called directly by applications, use GPIODeviceFunctionSelect instead


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