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I2C Class Reference
Public Member Functions | Static Public Member Functions

I2C Class Reference

An I2C Master, used for communicating with I2C slave devices. More...

#include <I2C.h>

Inherits mbed::Base.

Public Member Functions

 I2C (PinName sda, PinName scl, const char *name=NULL)
 Create an I2C Master interface, connected to the specified pins.
void frequency (int hz)
 Set the frequency of the I2C interface.
int read (int address, char *data, int length, bool repeated=false)
 Read from an I2C slave.
int read (int ack)
 Read a single byte from the I2C bus.
int write (int address, const char *data, int length, bool repeated=false)
 Write to an I2C slave.
int write (int data)
 Write single byte out on the I2C bus.
void start (void)
 Creates a start condition on the I2C bus.
void stop (void)
 Creates a stop condition on the I2C bus.
void register_object (const char *name)
 Registers this object with the given name, so that it can be looked up with lookup.
const char * name ()
 Returns the name of the object.
virtual bool rpc (const char *method, const char *arguments, char *result)
 Call the given method with the given arguments, and write the result into the string pointed to by result.
virtual struct rpc_method * get_rpc_methods ()
 Returns a pointer to an array describing the rpc methods supported by this object, terminated by either RPC_METHOD_END or RPC_METHOD_SUPER(Superclass).

Static Public Member Functions

static bool rpc (const char *name, const char *method, const char *arguments, char *result)
 Use the lookup function to lookup an object and, if successful, call its rpc method.
static Base * lookup (const char *name, unsigned int len)
 Lookup and return the object that has the given name.
template<class C >
static void add_rpc_class ()
 Add the class to the list of classes which can have static methods called via rpc (the static methods which can be called are defined by that class' get_rpc_class() static method).

Detailed Description

An I2C Master, used for communicating with I2C slave devices.

Example: 

 // Read from I2C slave at address 0x62

 #include "mbed.h"

 I2C i2c(p28, p27);

 int main() {
     int address = 0x62;
     char data[2];
     i2c.read(address, data, 2);
 }

Definition at line 36 of file I2C.h.

Constructor & Destructor Documentation

I2C ( PinName  sda,
PinName  scl,
const char *  name = NULL 
)

Create an I2C Master interface, connected to the specified pins.

Parameters:
sdaI2C data line pin
sclI2C clock line pin

Member Function Documentation

static void add_rpc_class (  ) [static, inherited]

Add the class to the list of classes which can have static methods called via rpc (the static methods which can be called are defined by that class' get_rpc_class() static method).

Definition at line 143 of file Base.h.

void frequency ( int  hz )

Set the frequency of the I2C interface.

Parameters:
hzThe bus frequency in hertz
virtual struct rpc_method* get_rpc_methods (  ) [read, virtual, inherited]

Returns a pointer to an array describing the rpc methods supported by this object, terminated by either RPC_METHOD_END or RPC_METHOD_SUPER(Superclass).

Example 

 class Example : public Base {
     int foo(int a, int b) { return a + b; }
     virtual const struct rpc_method *get_rpc_methods() {
         static const rpc_method rpc_methods[] = {
             { "foo", generic_caller<int, Example, int, int, &Example::foo> },
             RPC_METHOD_SUPER(Base)
         };
         return rpc_methods;
     }
 };

Reimplemented in AnalogIn, AnalogOut, BusIn, BusInOut, BusOut, DigitalIn, DigitalInOut, DigitalOut, PwmOut, Serial, SPI, and Timer.

static Base* lookup ( const char *  name,
unsigned int  len 
) [static, inherited]

Lookup and return the object that has the given name.

Parameters:
namethe name to lookup.
lenthe length of name.
const char* name (  ) [inherited]

Returns the name of the object.

Returns:
The name of the object, or NULL if it has no name.
int read ( int  address,
char *  data,
int  length,
bool  repeated = false 
)

Read from an I2C slave.

Performs a complete read transaction. The bottom bit of the address is forced to 1 to indicate a read.

Parameters:
address8-bit I2C slave address [ addr | 1 ]
dataPointer to the byte-array to read data in to
lengthNumber of bytes to read
repeatedRepeated start, true - don't send stop at end
Returns:
0 on success (ack), non-0 on failure (nack)
int read ( int  ack )

Read a single byte from the I2C bus.

Parameters:
ackindicates if the byte is to be acknowledged (1 = acknowledge)
Returns:
the byte read
void register_object ( const char *  name ) [inherited]

Registers this object with the given name, so that it can be looked up with lookup.

If this object has already been registered, then this just changes the name.

Parameters:
nameThe name to give the object. If NULL we do nothing.
virtual bool rpc ( const char *  method,
const char *  arguments,
char *  result 
) [virtual, inherited]

Call the given method with the given arguments, and write the result into the string pointed to by result.

The default implementation calls rpc_methods to determine the supported methods.

Parameters:
methodThe name of the method to call.
argumentsA list of arguments separated by spaces.
resultA pointer to a string to write the result into. May be NULL, in which case nothing is written.
Returns:
true if method corresponds to a valid rpc method, or false otherwise.
static bool rpc ( const char *  name,
const char *  method,
const char *  arguments,
char *  result 
) [static, inherited]

Use the lookup function to lookup an object and, if successful, call its rpc method.

Returns:
false if name does not correspond to an object, otherwise the return value of the call to the object's rpc method.
void start ( void   )

Creates a start condition on the I2C bus.

void stop ( void   )

Creates a stop condition on the I2C bus.

int write ( int  address,
const char *  data,
int  length,
bool  repeated = false 
)

Write to an I2C slave.

Performs a complete write transaction. The bottom bit of the address is forced to 0 to indicate a write.

Parameters:
address8-bit I2C slave address [ addr | 0 ]
dataPointer to the byte-array data to send
lengthNumber of bytes to send
repeatedRepeated start, true - do not send stop at end
Returns:
0 on success (ack), non-0 on failure (nack)
int write ( int  data )

Write single byte out on the I2C bus.

Parameters:
datadata to write out on bus
Returns:
'1' if an ACK was received, '0' otherwise
Generated on Tue Jul 12 2022 11:27:31 by  doxygen 1.7.2