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I2CSlave.h
- Committer:
- simon
- Date:
- 2010-07-08
- Revision:
- 22:9114680c05da
- Child:
- 27:7110ebee3484
File content as of revision 22:9114680c05da:
/* mbed Microcontroller Library - I2CSlave * Copyright (c) 2007-2010 ARM Limited. All rights reserved. * jward */ #ifndef MBED_I2C_SLAVE_H #define MBED_I2C_SLAVE_H #include "platform.h" #include "PinNames.h" #include "PeripheralNames.h" #include "Base.h" namespace mbed { /* Class: I2CSlave * An I2C Slave, used for communicating with an I2C Master device * * Example: * > // Simple I2C responder * > #include <mbed.h> * > * > I2CSlave slave(p9, p10); * > * > int main() { * > char buf[10]; * > char msg[] = "Slave!"; * > * > slave.address(0xA0); * > while (1) { * > int i = slave.receive(); * > switch (i) { * > case I2CSlave::ReadAddressed: * > slave.write(msg, strlen(msg) + 1); // Includes null char * > break; * > case I2CSlave::WriteGeneral: * > slave.read(buf, 10); * > printf("Read G: %s\n", buf); * > break; * > case I2CSlave::WriteAddressed: * > slave.read(buf, 10); * > printf("Read A: %s\n", buf); * > break; * > } * > for(int i = 0; i < 10; i++) buf[i] = 0; // Clear buffer * > } * > } * > */ class I2CSlave : public Base { public: enum RxStatus { NoData = 0 , ReadAddressed = 1 , WriteGeneral = 2 , WriteAddressed = 3 }; /* Constructor: I2CSlave * Create an I2C Slave interface, connected to the specified pins. * * Variables: * sda - I2C data line pin * scl - I2C clock line pin */ I2CSlave(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: receive * Checks to see if this I2C Slave has been addressed. * * Variables: * returns - a status indicating if the device has been addressed, and how * > NoData - the slave has not been addressed * > ReadAddressed - the master has requested a read from this slave * > WriteAddressed - the master is writing to this slave * > WriteGeneral - the master is writing to all slave */ int receive(void); /* Function: read * Read from an I2C master. * * Variables: * data - pointer to the byte array to read data in to * length - maximum number of bytes to read * returns - 0 on success, non-0 otherwise */ int read(char *data, int length); /* Function: read * Read a single byte from an I2C master. * * Variables: * returns - the byte read */ int read(void); /* Function: write * Write to an I2C master. * * Variables: * data - pointer to the byte array to be transmitted * length - the number of bytes to transmite * returns - a 0 on success, non-0 otherwise */ int write(const char *data, int length); /* Function: write * Write a single byte to an I2C master. * * Variables * data - the byte to write * returns - a '1' if an ACK was received, a '0' otherwise */ int write(int data); /* Function: address * Sets the I2C slave address. * * Variables * address - the address to set for the slave (ignoring the least * signifcant bit). If set to 0, the slave will only respond to the * general call address. */ void address(int address); /* Function: stop * Reset the I2C slave back into the known ready receiving state. */ void stop(void); protected: I2CName _i2c; }; } // namespace mbed #endif