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Diff: I2C.h
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diff -r 000000000000 -r a8fa94490a0a I2C.h --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/I2C.h Sat Sep 22 10:32:07 2012 +0000 @@ -0,0 +1,142 @@ +/* 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 +