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The official Mbed 2 C/C++ SDK provides the software platform and libraries to build your applications.

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mbed 2

This is the mbed 2 library. If you'd like to learn about Mbed OS please see the mbed-os docs.

drivers/I2CSlave.h@172:65be27845400, 2019-02-20 (annotated)

Committer:
AnnaBridge
Date:
Wed Feb 20 20:53:29 2019 +0000
Revision:
172:65be27845400
Parent:
171:3a7713b1edbc 
mbed library release version 165

Who changed what in which revision?

UserRevisionLine numberNew contents of line
AnnaBridge 156:ff21514d8981 1 /* mbed Microcontroller Library
AnnaBridge 156:ff21514d8981 2 * Copyright (c) 2006-2013 ARM Limited
AnnaBridge 172:65be27845400 3 * SPDX-License-Identifier: Apache-2.0
AnnaBridge 156:ff21514d8981 4 *
AnnaBridge 156:ff21514d8981 5 * Licensed under the Apache License, Version 2.0 (the "License");
AnnaBridge 156:ff21514d8981 6 * you may not use this file except in compliance with the License.
AnnaBridge 156:ff21514d8981 7 * You may obtain a copy of the License at
AnnaBridge 156:ff21514d8981 8 *
AnnaBridge 156:ff21514d8981 9 * http://www.apache.org/licenses/LICENSE-2.0
AnnaBridge 156:ff21514d8981 10 *
AnnaBridge 156:ff21514d8981 11 * Unless required by applicable law or agreed to in writing, software
AnnaBridge 156:ff21514d8981 12 * distributed under the License is distributed on an "AS IS" BASIS,
AnnaBridge 156:ff21514d8981 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
AnnaBridge 156:ff21514d8981 14 * See the License for the specific language governing permissions and
AnnaBridge 156:ff21514d8981 15 * limitations under the License.
AnnaBridge 156:ff21514d8981 16 */
AnnaBridge 156:ff21514d8981 17 #ifndef MBED_I2C_SLAVE_H
AnnaBridge 156:ff21514d8981 18 #define MBED_I2C_SLAVE_H
AnnaBridge 156:ff21514d8981 19
AnnaBridge 156:ff21514d8981 20 #include "platform/platform.h"
AnnaBridge 156:ff21514d8981 21
AnnaBridge 172:65be27845400 22 #if DEVICE_I2CSLAVE || defined(DOXYGEN_ONLY)
AnnaBridge 156:ff21514d8981 23
AnnaBridge 156:ff21514d8981 24 #include "hal/i2c_api.h"
AnnaBridge 156:ff21514d8981 25
AnnaBridge 156:ff21514d8981 26 namespace mbed {
AnnaBridge 156:ff21514d8981 27 /** \addtogroup drivers */
AnnaBridge 156:ff21514d8981 28
AnnaBridge 171:3a7713b1edbc 29 /** An I2C Slave, used for communicating with an I2C Master device.
AnnaBridge 156:ff21514d8981 30 *
AnnaBridge 156:ff21514d8981 31 * @note Synchronization level: Not protected
AnnaBridge 156:ff21514d8981 32 *
AnnaBridge 171:3a7713b1edbc 33 * Example Simple I2C responder:
AnnaBridge 156:ff21514d8981 34 * @code
AnnaBridge 156:ff21514d8981 35 * #include <mbed.h>
AnnaBridge 156:ff21514d8981 36 *
AnnaBridge 171:3a7713b1edbc 37 * const int SLAVE_ADDRESS = 0xA0;
AnnaBridge 171:3a7713b1edbc 38 * const char message[] = "Slave!";
AnnaBridge 171:3a7713b1edbc 39 *
AnnaBridge 171:3a7713b1edbc 40 * I2CSlave slave(I2C_SDA, I2C_SCL);
AnnaBridge 156:ff21514d8981 41 *
AnnaBridge 156:ff21514d8981 42 * int main() {
AnnaBridge 171:3a7713b1edbc 43 * slave.address(SLAVE_ADDRESS);
AnnaBridge 156:ff21514d8981 44 * while (1) {
AnnaBridge 171:3a7713b1edbc 45 * int operation = slave.receive();
AnnaBridge 171:3a7713b1edbc 46 * switch (operation) {
AnnaBridge 156:ff21514d8981 47 * case I2CSlave::ReadAddressed:
AnnaBridge 171:3a7713b1edbc 48 * int status = slave.write(message, sizeof(message));
AnnaBridge 171:3a7713b1edbc 49 * if (status == 0) {
AnnaBridge 171:3a7713b1edbc 50 * printf("Written message: %s\n", message);
AnnaBridge 171:3a7713b1edbc 51 * } else {
AnnaBridge 171:3a7713b1edbc 52 * printf("Failed to write message.\n");
AnnaBridge 171:3a7713b1edbc 53 * }
AnnaBridge 156:ff21514d8981 54 * break;
AnnaBridge 156:ff21514d8981 55 * case I2CSlave::WriteGeneral:
AnnaBridge 171:3a7713b1edbc 56 * int byte_read = slave.read();
AnnaBridge 171:3a7713b1edbc 57 * printf("Read General: %c (%d)\n", byte_read, byte_read);
AnnaBridge 156:ff21514d8981 58 * break;
AnnaBridge 156:ff21514d8981 59 * case I2CSlave::WriteAddressed:
AnnaBridge 171:3a7713b1edbc 60 * int byte_read = slave.read();
AnnaBridge 171:3a7713b1edbc 61 * printf("Read Addressed: %c (%d)\n", byte_read, byte_read);
AnnaBridge 156:ff21514d8981 62 * break;
AnnaBridge 156:ff21514d8981 63 * }
AnnaBridge 156:ff21514d8981 64 * }
AnnaBridge 156:ff21514d8981 65 * }
AnnaBridge 156:ff21514d8981 66 * @endcode
AnnaBridge 156:ff21514d8981 67 * @ingroup drivers
AnnaBridge 156:ff21514d8981 68 */
AnnaBridge 156:ff21514d8981 69 class I2CSlave {
AnnaBridge 156:ff21514d8981 70
AnnaBridge 156:ff21514d8981 71 public:
AnnaBridge 156:ff21514d8981 72 enum RxStatus {
AnnaBridge 156:ff21514d8981 73 NoData = 0,
AnnaBridge 156:ff21514d8981 74 ReadAddressed = 1,
AnnaBridge 156:ff21514d8981 75 WriteGeneral = 2,
AnnaBridge 156:ff21514d8981 76 WriteAddressed = 3
AnnaBridge 156:ff21514d8981 77 };
AnnaBridge 156:ff21514d8981 78
AnnaBridge 156:ff21514d8981 79 /** Create an I2C Slave interface, connected to the specified pins.
AnnaBridge 156:ff21514d8981 80 *
AnnaBridge 171:3a7713b1edbc 81 * @param sda I2C data line pin.
AnnaBridge 171:3a7713b1edbc 82 * @param scl I2C clock line pin.
AnnaBridge 156:ff21514d8981 83 */
AnnaBridge 156:ff21514d8981 84 I2CSlave(PinName sda, PinName scl);
AnnaBridge 156:ff21514d8981 85
AnnaBridge 171:3a7713b1edbc 86 /** Set the frequency of the I2C interface.
AnnaBridge 156:ff21514d8981 87 *
AnnaBridge 171:3a7713b1edbc 88 * @param hz The bus frequency in Hertz.
AnnaBridge 156:ff21514d8981 89 */
AnnaBridge 156:ff21514d8981 90 void frequency(int hz);
AnnaBridge 156:ff21514d8981 91
AnnaBridge 171:3a7713b1edbc 92 /** Check if this I2C Slave has been addressed.
AnnaBridge 156:ff21514d8981 93 *
AnnaBridge 171:3a7713b1edbc 94 * @return A status indicating if the device has been addressed and how.
AnnaBridge 171:3a7713b1edbc 95 * @retval NoData The slave has not been addressed.
AnnaBridge 171:3a7713b1edbc 96 * @retval ReadAddressed The master has requested a read from this slave.
AnnaBridge 171:3a7713b1edbc 97 * @retval WriteAddressed The master is writing to this slave.
AnnaBridge 171:3a7713b1edbc 98 * @retval WriteGeneral The master is writing to all slave.
AnnaBridge 156:ff21514d8981 99 */
AnnaBridge 156:ff21514d8981 100 int receive(void);
AnnaBridge 156:ff21514d8981 101
AnnaBridge 171:3a7713b1edbc 102 /** Read specified number of bytes from an I2C master.
AnnaBridge 156:ff21514d8981 103 *
AnnaBridge 171:3a7713b1edbc 104 * @param data Pointer to the buffer to read data into.
AnnaBridge 171:3a7713b1edbc 105 * @param length Number of bytes to read.
AnnaBridge 156:ff21514d8981 106 *
AnnaBridge 171:3a7713b1edbc 107 * @return Result of the operation.
AnnaBridge 171:3a7713b1edbc 108 * @retval 0 If the number of bytes read is equal to length requested.
AnnaBridge 171:3a7713b1edbc 109 * @retval nonzero On error or if the number of bytes read is less than requested.
AnnaBridge 156:ff21514d8981 110 */
AnnaBridge 156:ff21514d8981 111 int read(char *data, int length);
AnnaBridge 156:ff21514d8981 112
AnnaBridge 156:ff21514d8981 113 /** Read a single byte from an I2C master.
AnnaBridge 156:ff21514d8981 114 *
AnnaBridge 171:3a7713b1edbc 115 * @return The byte read.
AnnaBridge 156:ff21514d8981 116 */
AnnaBridge 156:ff21514d8981 117 int read(void);
AnnaBridge 156:ff21514d8981 118
AnnaBridge 156:ff21514d8981 119 /** Write to an I2C master.
AnnaBridge 156:ff21514d8981 120 *
AnnaBridge 171:3a7713b1edbc 121 * @param data Pointer to the buffer containing the data to be sent.
AnnaBridge 171:3a7713b1edbc 122 * @param length Number of bytes to send.
AnnaBridge 156:ff21514d8981 123 *
AnnaBridge 171:3a7713b1edbc 124 * @return
AnnaBridge 171:3a7713b1edbc 125 * @retval 0 If written all bytes successfully.
AnnaBridge 171:3a7713b1edbc 126 * @retval nonzero On error or if the number of bytes written is less than requested.
AnnaBridge 156:ff21514d8981 127 */
AnnaBridge 156:ff21514d8981 128 int write(const char *data, int length);
AnnaBridge 156:ff21514d8981 129
AnnaBridge 156:ff21514d8981 130 /** Write a single byte to an I2C master.
AnnaBridge 156:ff21514d8981 131 *
AnnaBridge 171:3a7713b1edbc 132 * @param data Value to write.
AnnaBridge 156:ff21514d8981 133 *
AnnaBridge 171:3a7713b1edbc 134 * @return Result of the operation.
AnnaBridge 171:3a7713b1edbc 135 * @retval 0 If a NACK is received.
AnnaBridge 171:3a7713b1edbc 136 * @retval 1 If an ACK is received.
AnnaBridge 171:3a7713b1edbc 137 * @retval 2 On timeout.
AnnaBridge 156:ff21514d8981 138 */
AnnaBridge 156:ff21514d8981 139 int write(int data);
AnnaBridge 156:ff21514d8981 140
AnnaBridge 171:3a7713b1edbc 141 /** Set the I2C slave address.
AnnaBridge 156:ff21514d8981 142 *
AnnaBridge 171:3a7713b1edbc 143 * @param address The address to set for the slave (least significant bit is ignored).
AnnaBridge 171:3a7713b1edbc 144 *
AnnaBridge 171:3a7713b1edbc 145 * @note If address is set to 0, the slave will only respond to the
AnnaBridge 156:ff21514d8981 146 * general call address.
AnnaBridge 156:ff21514d8981 147 */
AnnaBridge 156:ff21514d8981 148 void address(int address);
AnnaBridge 156:ff21514d8981 149
AnnaBridge 156:ff21514d8981 150 /** Reset the I2C slave back into the known ready receiving state.
AnnaBridge 156:ff21514d8981 151 */
AnnaBridge 156:ff21514d8981 152 void stop(void);
AnnaBridge 156:ff21514d8981 153
AnnaBridge 171:3a7713b1edbc 154 #if !defined(DOXYGEN_ONLY)
AnnaBridge 171:3a7713b1edbc 155
AnnaBridge 156:ff21514d8981 156 protected:
AnnaBridge 171:3a7713b1edbc 157 /* Internal i2c object identifying the resources */
AnnaBridge 156:ff21514d8981 158 i2c_t _i2c;
AnnaBridge 171:3a7713b1edbc 159
AnnaBridge 171:3a7713b1edbc 160 #endif //!defined(DOXYGEN_ONLY)
AnnaBridge 156:ff21514d8981 161 };
AnnaBridge 156:ff21514d8981 162
AnnaBridge 156:ff21514d8981 163 } // namespace mbed
AnnaBridge 156:ff21514d8981 164
AnnaBridge 156:ff21514d8981 165 #endif
AnnaBridge 156:ff21514d8981 166
AnnaBridge 156:ff21514d8981 167 #endif