mbed library sources
Dependents: frdm_kl05z_gpio_test
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Diff: cpp/I2CSlave.h
- Revision:
- 0:fd0d7bdfcdc2
- Child:
- 2:143cac498751
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/cpp/I2CSlave.h Tue Nov 20 17:24:08 2012 +0000 @@ -0,0 +1,160 @@ +/* mbed Microcontroller Library + * Copyright (c) 2006-2012 ARM Limited + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + * SOFTWARE. + */ +#ifndef MBED_I2C_SLAVE_H +#define MBED_I2C_SLAVE_H + +#include "platform.h" + +#if DEVICE_I2CSLAVE + +#include "i2c_api.h" + +namespace mbed { + +/** An I2C Slave, used for communicating with an I2C Master device + * + * Example: + * @code + * // 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 + * } + * } + * @endcode + */ +class I2CSlave { + +public: + enum RxStatus { + NoData = 0, + ReadAddressed = 1, + WriteGeneral = 2, + WriteAddressed = 3 + }; + + /** Create an I2C Slave interface, connected to the specified pins. + * + * @param sda I2C data line pin + * @param scl I2C clock line pin + */ + I2CSlave(PinName sda, PinName scl); + + /** Set the frequency of the I2C interface + * + * @param hz The bus frequency in hertz + */ + void frequency(int hz); + + /** Checks to see if this I2C Slave has been addressed. + * + * @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); + + /** Read from an I2C master. + * + * @param data pointer to the byte array to read data in to + * @param length maximum number of bytes to read + * + * @returns + * 0 on success, + * non-0 otherwise + */ + int read(char *data, int length); + + /** Read a single byte from an I2C master. + * + * @returns + * the byte read + */ + int read(void); + + /** Write to an I2C master. + * + * @param data pointer to the byte array to be transmitted + * @param length the number of bytes to transmite + * + * @returns + * 0 on success, + * non-0 otherwise + */ + int write(const char *data, int length); + + /** Write a single byte to an I2C master. + * + * @data the byte to write + * + * @returns + * '1' if an ACK was received, + * '0' otherwise + */ + int write(int data); + + /** Sets the I2C slave address. + * + * @param 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); + + /** Reset the I2C slave back into the known ready receiving state. + */ + void stop(void); + +protected: + i2c_t _i2c; +}; + +} // namespace mbed + +#endif + +#endif