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I2C.h
- Committer:
- Jing_Qiu
- Date:
- 2015-03-03
- Revision:
- 1:27d81db81dd7
- Parent:
- 0:a8fa94490a0a
File content as of revision 1:27d81db81dd7:
/* mbed Microcontroller Library - I2C * Copyright (c) 2007-2011 ARM Limited. All rights reserved. */ #ifndef MBED_I2C_H #define MBED_I2C_H #include "device.h" #if DEVICE_I2C #include "platform.h" #include "PinNames.h" #include "PeripheralNames.h" #include "Base.h" namespace mbed { /* Class: I2C * 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); * > } */ class I2C : public Base { public: enum RxStatus { NoData , MasterGeneralCall , MasterWrite , MasterRead }; enum Acknowledge { NoACK = 0 , ACK = 1 }; /* Constructor: I2C * Create an I2C Master interface, connected to the specified pins * * Variables: * sda - I2C data line pin * scl - I2C clock line pin */ I2C(PinName sda, PinName scl, const char *name = NULL); /* Function: frequency * Set the frequency of the I2C interface * * Variables: * hz - The bus frequency in hertz */ void frequency(int hz); /* Function: read * Read from an I2C slave * * Performs a complete read transaction. The bottom bit of * the address is forced to 1 to indicate a read. * * Variables: * address - 8-bit I2C slave address [ addr | 1 ] * data - Pointer to the byte-array to read data in to * length - Number of bytes to read * repeated - Repeated start, true - don't send stop at end * returns - 0 on success (ack), or non-0 on failure (nack) */ int read(int address, char *data, int length, bool repeated = false); /* Function: read * Read a single byte from the I2C bus * * Variables: * ack - indicates if the byte is to be acknowledged (1 = acknowledge) * returns - the byte read */ int read(int ack); /* Function: write * Write to an I2C slave * * Performs a complete write transaction. The bottom bit of * the address is forced to 0 to indicate a write. * * Variables: * address - 8-bit I2C slave address [ addr | 0 ] * data - Pointer to the byte-array data to send * length - Number of bytes to send * repeated - Repeated start, true - do not send stop at end * returns - 0 on success (ack), or non-0 on failure (nack) */ int write(int address, const char *data, int length, bool repeated = false); /* Function: write * Write single byte out on the I2C bus * * Variables: * data - data to write out on bus * returns - a '1' if an ACK was received, a '0' otherwise */ int write(int data); /* Function: start * Creates a start condition on the I2C bus */ void start(void); /* Function: stop * Creates a stop condition on the I2C bus */ void stop(void); protected: void aquire(); I2CName _i2c; static I2C *_owner; int _hz; }; } // namespace mbed #endif #endif