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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@171:3a7713b1edbc, 2018-11-08 (annotated)

Committer:
AnnaBridge
Date:
Thu Nov 08 11:45:42 2018 +0000
Revision:
171:3a7713b1edbc
Parent:
156:ff21514d8981
Child:
172:65be27845400
mbed library. Release version 164

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