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Diff: I2CSlave.h
- Revision:
- 22:9114680c05da
- Child:
- 27:7110ebee3484
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/I2CSlave.h Thu Jul 08 14:27:15 2010 +0000 @@ -0,0 +1,149 @@ +/* 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