Yann Garcia / MCP4xxxx_SPI

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Dependents:   MCP41xxxApp MCP320xApp MCP41xxxApp

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CMCP4xxxx_SPI Class Reference
Public Types | Public Member Functions

CMCP4xxxx_SPI Class Reference

This class provides simplified SPI access to a Microchip MCP42xxx/MCP41xxx Digital Potentiometer device. More...

#include <MCP4xxxx_SPI.h>

Public Types

enum  Mcp4xxxFamily
 

MCP32xx family.

More...
enum  Commands
 

Authorized commands See DS11195C-page 18.

More...
enum  Addresses
 

Register adresses See DS22060B-page 33 Clause 4.0 FUNCTIONAL OVERVIEW.

More...

Public Member Functions

 CMCP4xxxx_SPI (const PinName p_mosi, const PinName p_miso, const PinName p_sclk, const PinName p_cs=NC, const PinName p_reset=NC, const PinName p_shdn=NC, const Mcp4xxxFamily family=_41xxx, const unsigned int p_frequency=1000000)
 Constructor with Write Protect command pin wired.
virtual ~CMCP4xxxx_SPI ()
 Destructor.
const SPI * operator* ()
 Used to return the unique instance of SPI instance.
unsigned short WriteRegister (const Addresses p_address, const unsigned char p_value)
 Write a value to the specified register.
unsigned short ReadRegister (const Addresses p_address)
 Read the content of the specified register.
unsigned short Increment (const Commands p_command=WriteToDigiPot1)
 Increment the specified digital potentiometer.
unsigned short Decrement (const Commands p_command=WriteToDigiPot1)
 Decrement the specified digital potentiometer.
unsigned short Write (const Commands p_command, const unsigned char p_value)
 Send a write a command (WriteToPot1, WriteToPot2 or WriteBoth)
unsigned short Shutdown (const Commands p_command, const bool p_set=true)
 Send a shutdown a command (ShutdownPot1, ShutdownPot2 or ShutdownBoth)
Mcp4xxxFamily SetFamilly (const Mcp4xxxFamily family)
 Write a NOP command.
void Reset ()
 Reset the device.
void Shutdown (const bool p_set)
 Shutdown the device.

Detailed Description

This class provides simplified SPI access to a Microchip MCP42xxx/MCP41xxx Digital Potentiometer device.

V0.0.0.2 The SPI static settings are: 16bits, mode (0,0) This class manages ONLY ONE /CS pin. If more than one SPI devices are used, ALL /CS pins shall be done by the application itself

Microchip MCP42xxx/MCP41xxx Serial EEPROM device reference: DS11195C Microchip MCP41xx/MCP42xx Serial EEPROM device reference: DS122060B

Note that MCP41xxx has no SO pin, only a SOI input pin Note that MCP42xxx has a SO pin reserved for daisy-chain configuration Note that MCP41xx/MCP42xx increment/decrement operations are not supported due to the 16 bits SPI setting Note that for SPI details, please visit http://en.wikipedia.org/wiki/Serial_Peripheral_Interface_Bus

Remarks:
This class was validated with Tektronix TDS2014 oscilloscope in 3.3V and in mixte power mode 3.3V for mbed and 5V for the Microchip 24LCxx Serial EEPROM device
Author:
Yann Garcia (Don't hesitate to contact me: garcia.yann@gmail.com)

Definition at line 44 of file MCP4xxxx_SPI.h.

Member Enumeration Documentation

enum Addresses

Register adresses See DS22060B-page 33 Clause 4.0 FUNCTIONAL OVERVIEW.

Definition at line 92 of file MCP4xxxx_SPI.h.

enum Commands

Authorized commands See DS11195C-page 18.

Definition at line 81 of file MCP4xxxx_SPI.h.

enum Mcp4xxxFamily

MCP32xx family.

Definition at line 70 of file MCP4xxxx_SPI.h.

Constructor & Destructor Documentation

CMCP4xxxx_SPI ( const PinName  p_mosi,
const PinName  p_miso,
const PinName  p_sclk,
const PinName  p_cs = NC,
const PinName  p_reset = NC,
const PinName  p_shdn = NC,
const Mcp4xxxFamily  family = _41xxx,
const unsigned int  p_frequency = 1000000 
)

Constructor with Write Protect command pin wired.

Parameters:
p_mosi,:MBed pin for SDI
p_miso,:MBed pin for SDO. Note that this pin does not exist for MCP41xxx
p_sclk,:MBed pin for CLK
p_cs: MBed pin for Chip Select. If NC, assumes that application manage /CS, default value is NC, not connected
p_reset,:MBed pin to manage /RESET input. If NC, /RESET is not managed, default value is NC, not connected
p_shdn,:MBed pin to manage /SHDN input. If NC, /SHDN is not managed, default value is NC, not connected
p_frequency,:Frequency of the SPI interface (SCK), default value is 1MHz

Definition at line 26 of file MCP4xxxx_SPI.cpp.

~CMCP4xxxx_SPI (  ) [virtual]

Destructor.

Definition at line 74 of file MCP4xxxx_SPI.cpp.

Member Function Documentation

unsigned short Decrement ( const Commands  p_command = WriteToDigiPot1 )

Decrement the specified digital potentiometer.

Parameters:
p_commandThe digital potentiometer to decrement. Default: WriteToDigiPot1
Returns:
0x0000 on success, any value otherwise

Definition at line 155 of file MCP4xxxx_SPI.cpp.

unsigned short Increment ( const Commands  p_command = WriteToDigiPot1 )

Increment the specified digital potentiometer.

Parameters:
p_commandThe digital potentiometer to increment. Default: WriteToDigiPot1
Returns:
0x0000 on success, any value otherwise

Definition at line 147 of file MCP4xxxx_SPI.cpp.

const SPI* operator* (  )

Used to return the unique instance of SPI instance.

Definition at line 115 of file MCP4xxxx_SPI.h.

unsigned short ReadRegister ( const Addresses  p_address )

Read the content of the specified register.

Only for _41xx/_42xx famillies

Parameters:
p_addressThe register to be written
Returns:
The register value

Definition at line 128 of file MCP4xxxx_SPI.cpp.

void Reset (  )

Reset the device. 

 unsigned char potLevel;
 ...
 g_digitalPot.Reset();
 ...

Definition at line 289 of file MCP4xxxx_SPI.cpp.

CMCP4xxxx_SPI::Mcp4xxxFamily SetFamilly ( const Mcp4xxxFamily  family )

Write a NOP command.

Change the current family

Parameters:
familyThe new type of ICs
Returns:
the previous type of ICs

Definition at line 273 of file MCP4xxxx_SPI.cpp.

void Shutdown ( const bool  p_set )

Shutdown the device.

Definition at line 299 of file MCP4xxxx_SPI.cpp.

unsigned short Shutdown ( const Commands  p_command,
const bool  p_set = true 
)

Send a shutdown a command (ShutdownPot1, ShutdownPot2 or ShutdownBoth)

Parameters:
p_commandThe command to execute (See DS11195C-page 18)
p_setSet to true to shutdown, false to set up. Only used for _41xx/_42xx famillies (See DS22060B-page 36 REGISTER 4-2: TCON BITS)
Returns:
0x0000 on success, 0Xffff otherwise Exemple: 
 ...
 g_chipSelect.write(0);
 g_digitalPot.Shutdown(CMCP4xxxx_SPI::ShutdownPot1);
 g_chipSelect.write(1);
 ...

Definition at line 208 of file MCP4xxxx_SPI.cpp.

unsigned short Write ( const Commands  p_command,
const unsigned char  p_value 
)

Send a write a command (WriteToPot1, WriteToPot2 or WriteBoth)

Parameters:
p_commandThe command to execute (See DS11195C-page 18)
p_valueThe potentiometer selection bits (See DS11195C-page 14 Clause 4.1 Modes of Operation)
Returns:
0x0000 on success, 0Xffff otherwise Exemple: 
 unsigned char potLevel;
 ...
 g_chipSelect.write(0);
 g_digitalPot.Write(CMCP4xxxx_SPI::WriteToPot2, potLevel);
 g_chipSelect.write(1);
 ...

Definition at line 164 of file MCP4xxxx_SPI.cpp.

unsigned short WriteRegister ( const Addresses  p_address,
const unsigned char  p_value 
)

Write a value to the specified register.

Only for _41xx/_42xx famillies

Parameters:
p_addressThe register to be written
p_valueThe value to write
Returns:
0x0000 on success, any value otherwise

Definition at line 103 of file MCP4xxxx_SPI.cpp.

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