t
Fork of mbed-dev by
drivers/I2CSlave.h
- Committer:
- amithy
- Date:
- 2017-11-09
- Revision:
- 178:c26431f84b0d
- Parent:
- 149:156823d33999
- Child:
- 167:e84263d55307
File content as of revision 178:c26431f84b0d:
/* mbed Microcontroller Library * Copyright (c) 2006-2013 ARM Limited * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ #ifndef MBED_I2C_SLAVE_H #define MBED_I2C_SLAVE_H #include "platform/platform.h" #if DEVICE_I2CSLAVE #include "hal/i2c_api.h" namespace mbed { /** \addtogroup drivers */ /** @{*/ /** An I2C Slave, used for communicating with an I2C Master device * * @Note Synchronization level: Not protected * * 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 /** @}*/