modm API documentation

#include <modm/architecture/interface/i2c_master.hpp>

Inheritance diagram for modm::I2cMaster:
modm::PeripheralDriver modm::I2c modm::I2cMultiplexerChannel< multiplexer, channel > modm::platform::BitBangI2cMaster< Scl, Sda >

Public Types

enum  Error : uint8_t {
  Error::NoError, Error::SoftwareReset, Error::AddressNack, Error::DataNack,
  Error::ArbitrationLost, Error::BusCondition, Error::BusBusy, Error::Unknown
}
 Errors that can happen during master operation. More...
 
enum  PullUps { PullUps::External, PullUps::Internal }
 
enum  ResetDevices : uint32_t { ResetDevices::NoReset = 0, ResetDevices::LowSpeed = 10'000, ResetDevices::Standard = 100'000, ResetDevices::Fast = 400'000 }
 
- Public Types inherited from modm::I2c
enum  DetachCause : uint8_t { DetachCause::NormalStop, DetachCause::ErrorCondition, DetachCause::FailedToAttach }
 
enum  TransactionState : uint8_t { TransactionState::Idle, TransactionState::Busy, TransactionState::Error }
 State of a I2c Transaction. More...
 
enum  Operation : uint8_t { Operation::Stop = 0, Operation::Restart = 1, Operation::Write = 2, Operation::Read = 3 }
 All possible I2C Operations. More...
 
enum  OperationAfterStart : uint8_t { OperationAfterStart::Stop = uint8_t(Operation::Stop), OperationAfterStart::Write = uint8_t(Operation::Write), OperationAfterStart::Read = uint8_t(Operation::Read) }
 Further operations after start operation. More...
 
enum  OperationAfterWrite : uint8_t { OperationAfterWrite::Stop = uint8_t(Operation::Stop), OperationAfterWrite::Restart = uint8_t(Operation::Restart), OperationAfterWrite::Write = uint8_t(Operation::Write) }
 Further operations after write operation. More...
 
enum  OperationAfterRead : uint8_t { OperationAfterRead::Stop = uint8_t(Operation::Stop), OperationAfterRead::Restart = uint8_t(Operation::Restart) }
 Further operations after read operation. More...
 

Static Public Member Functions

template<class... Signals>
static void connect (PullUps pullups=PullUps::External, ResetDevices reset=ResetDevices::Standard)
 
template<class SystemClock , baudrate_t baudrate = 100_kBd, percent_t tolerance = 5_pct>
static void initialize ()
 
static bool start (I2cTransaction *transaction, ConfigurationHandler handler=nullptr)
 
static void reset ()
 
static Error getErrorState ()
 
- Static Public Member Functions inherited from modm::PeripheralDriver
static void initialize ()
 initializes the peripheral, must be called before use.
 
static void configurePurpose ()
 configures a peripheral for a specific purpose
 
static void setParameter ()
 sets a parameter
 
static void getParameter ()
 returns a parameter
 
static bool getInterruptFlag ()
 Read an interrupt flag.
 
static void acknowledgeInterruptFlag ()
 
template<baudrate_t available, baudrate_t requested, percent_t tolerance>
static void assertBaudrateInTolerance ()
 
- Static Public Member Functions inherited from modm::I2c
template<class Scl >
static void resetDevices (uint32_t baudrate=100'000)
 

Static Public Attributes

static constexpr size_t TransactionBufferSize = 8
 Number of transactions which can be queued in this driver.
 
- Static Public Attributes inherited from modm::I2c
static constexpr uint8_t Write = 0x00
 Add the Write bit to the slave address.
 
static constexpr uint8_t Read = 0x01
 Add the Read bit to the slave address.
 

Additional Inherited Members

- Public Typedefs inherited from modm::I2c
using ConfigurationHandler = void (*)()
 The signature of the configuration function.
 

Detailed Description

Interface of a I2C master.

Performing transfers in background allows the use of DMA etc. and enables the program to do other things while the operation is going on.

Author
Georgi Grinshpun
Niklas Hauser

Member Enumeration Documentation

enum modm::I2cMaster::Error : uint8_t
strong

Errors that can happen during master operation.

Enum ValuesDocumentation
NoError 

No Error occurred.

SoftwareReset 

The master was reset in software.

AddressNack 

Address was transmitted and NACK received.

DataNack 

Data was transmitted and NACK received.

ArbitrationLost 

Arbitration was lost during writing or reading.

BusCondition 

Misplaced Start or Stop condition.

BusBusy 

Bus is busy during Start condition.

Unknown 

Unknown error condition.

Enum ValuesDocumentation
External 

External pull-ups exists in SDA and SCL.

Internal 

Use weak internal pull-ups on SDA and SCL.

enum modm::I2cMaster::ResetDevices : uint32_t
strong
Enum ValuesDocumentation
NoReset 

Do not reset devices.

LowSpeed 

Low-Speed datarate of 10kHz.

Standard 

Standard datarate of 100kHz.

Fast 

Fast datarate of 400kHz.

Member Function Documentation

template<class... Signals>
static void modm::I2cMaster::connect ( PullUps  pullups = PullUps::External,
ResetDevices  reset = ResetDevices::Standard 
)
static

Configures the Scl and Sda signals and connects them.

This configures the Scl and Sda signals as open-drain outputs with optional weak internal pullups and optionally resets all slave devices on the bus.

Warning
Using weak internal pullups is not recommended and will require a slow baudrate. You must use external pullups for a reliable bus.
Template Parameters
SignalsOne Scl and one Sda signal are required and can be passed out-of-order.
Parameters
pullupsUse external or weak internal pullups.
resetChoose a speed to reset the I2C devices with. Can be disabled with ResetDevices::NoReset.
static Error modm::I2cMaster::getErrorState ( )
static

Check the error state of the driver.

The error states are hardware and implementation specific.

template<class SystemClock , baudrate_t baudrate = 100_kBd, percent_t tolerance = 5_pct>
static void modm::I2cMaster::initialize ( )
static

Initializes the hardware and sets the datarate.

Template Parameters
SystemClockthe currently active system clock
baudratethe desired baudrate in Hz
tolerancethe allowed absolute tolerance for the resulting baudrate
static void modm::I2cMaster::reset ( )
static

Perform a software reset of the driver in case of an error and detach the transaction object.

It is strongly recommended to reset the slave devices on the bus after a master reset. You can use the connect() method for that.

static bool modm::I2cMaster::start ( I2cTransaction transaction,
ConfigurationHandler  handler = nullptr 
)
static

Requests transaction attachment.

Parameters
transactionobject that inherits from the I2cTransaction class.
configurationfunction which configures the master for this transaction.
Returns
Caller gains control if true. Call has no effect if false.

The documentation for this class was generated from the following file: