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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/I2C.h@157:e7ca05fa8600, 2017-11-09 (annotated)

Committer:
AnnaBridge
Date:
Thu Nov 09 11:14:10 2017 +0000
Revision:
157:e7ca05fa8600
Parent:
156:ff21514d8981
Child:
160:5571c4ff569f
Release 155 of the mbed library.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
AnnaBridge 156:ff21514d8981 1 /* mbed Microcontroller Library
AnnaBridge 156:ff21514d8981 2 * Copyright (c) 2006-2015 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_H
AnnaBridge 156:ff21514d8981 17 #define MBED_I2C_H
AnnaBridge 156:ff21514d8981 18
AnnaBridge 156:ff21514d8981 19 #include "platform/platform.h"
AnnaBridge 156:ff21514d8981 20
AnnaBridge 156:ff21514d8981 21 #if defined (DEVICE_I2C) || defined(DOXYGEN_ONLY)
AnnaBridge 156:ff21514d8981 22
AnnaBridge 156:ff21514d8981 23 #include "hal/i2c_api.h"
AnnaBridge 156:ff21514d8981 24 #include "platform/SingletonPtr.h"
AnnaBridge 156:ff21514d8981 25 #include "platform/PlatformMutex.h"
AnnaBridge 156:ff21514d8981 26 #include "platform/NonCopyable.h"
AnnaBridge 156:ff21514d8981 27
AnnaBridge 156:ff21514d8981 28 #if DEVICE_I2C_ASYNCH
AnnaBridge 156:ff21514d8981 29 #include "platform/CThunk.h"
AnnaBridge 156:ff21514d8981 30 #include "hal/dma_api.h"
AnnaBridge 156:ff21514d8981 31 #include "platform/FunctionPointer.h"
AnnaBridge 156:ff21514d8981 32 #endif
AnnaBridge 156:ff21514d8981 33
AnnaBridge 156:ff21514d8981 34 namespace mbed {
AnnaBridge 156:ff21514d8981 35 /** \addtogroup drivers */
AnnaBridge 156:ff21514d8981 36
AnnaBridge 156:ff21514d8981 37 /** An I2C Master, used for communicating with I2C slave devices
AnnaBridge 156:ff21514d8981 38 *
AnnaBridge 156:ff21514d8981 39 * @note Synchronization level: Thread safe
AnnaBridge 156:ff21514d8981 40 *
AnnaBridge 156:ff21514d8981 41 * Example:
AnnaBridge 156:ff21514d8981 42 * @code
AnnaBridge 156:ff21514d8981 43 * // Read from I2C slave at address 0x62
AnnaBridge 156:ff21514d8981 44 *
AnnaBridge 156:ff21514d8981 45 * #include "mbed.h"
AnnaBridge 156:ff21514d8981 46 *
AnnaBridge 156:ff21514d8981 47 * I2C i2c(p28, p27);
AnnaBridge 156:ff21514d8981 48 *
AnnaBridge 156:ff21514d8981 49 * int main() {
AnnaBridge 156:ff21514d8981 50 * int address = 0x62;
AnnaBridge 156:ff21514d8981 51 * char data[2];
AnnaBridge 156:ff21514d8981 52 * i2c.read(address, data, 2);
AnnaBridge 156:ff21514d8981 53 * }
AnnaBridge 156:ff21514d8981 54 * @endcode
AnnaBridge 156:ff21514d8981 55 * @ingroup drivers
AnnaBridge 156:ff21514d8981 56 */
AnnaBridge 156:ff21514d8981 57 class I2C : private NonCopyable<I2C> {
AnnaBridge 156:ff21514d8981 58
AnnaBridge 156:ff21514d8981 59 public:
AnnaBridge 156:ff21514d8981 60 enum RxStatus {
AnnaBridge 156:ff21514d8981 61 NoData,
AnnaBridge 156:ff21514d8981 62 MasterGeneralCall,
AnnaBridge 156:ff21514d8981 63 MasterWrite,
AnnaBridge 156:ff21514d8981 64 MasterRead
AnnaBridge 156:ff21514d8981 65 };
AnnaBridge 156:ff21514d8981 66
AnnaBridge 156:ff21514d8981 67 enum Acknowledge {
AnnaBridge 156:ff21514d8981 68 NoACK = 0,
AnnaBridge 156:ff21514d8981 69 ACK = 1
AnnaBridge 156:ff21514d8981 70 };
AnnaBridge 156:ff21514d8981 71
AnnaBridge 156:ff21514d8981 72 /** Create an I2C Master interface, connected to the specified pins
AnnaBridge 156:ff21514d8981 73 *
AnnaBridge 156:ff21514d8981 74 * @param sda I2C data line pin
AnnaBridge 156:ff21514d8981 75 * @param scl I2C clock line pin
AnnaBridge 156:ff21514d8981 76 */
AnnaBridge 156:ff21514d8981 77 I2C(PinName sda, PinName scl);
AnnaBridge 156:ff21514d8981 78
AnnaBridge 156:ff21514d8981 79 /** Set the frequency of the I2C interface
AnnaBridge 156:ff21514d8981 80 *
AnnaBridge 156:ff21514d8981 81 * @param hz The bus frequency in hertz
AnnaBridge 156:ff21514d8981 82 */
AnnaBridge 156:ff21514d8981 83 void frequency(int hz);
AnnaBridge 156:ff21514d8981 84
AnnaBridge 156:ff21514d8981 85 /** Read from an I2C slave
AnnaBridge 156:ff21514d8981 86 *
AnnaBridge 156:ff21514d8981 87 * Performs a complete read transaction. The bottom bit of
AnnaBridge 156:ff21514d8981 88 * the address is forced to 1 to indicate a read.
AnnaBridge 156:ff21514d8981 89 *
AnnaBridge 156:ff21514d8981 90 * @param address 8-bit I2C slave address [ addr | 1 ]
AnnaBridge 156:ff21514d8981 91 * @param data Pointer to the byte-array to read data in to
AnnaBridge 156:ff21514d8981 92 * @param length Number of bytes to read
AnnaBridge 156:ff21514d8981 93 * @param repeated Repeated start, true - don't send stop at end
AnnaBridge 156:ff21514d8981 94 *
AnnaBridge 156:ff21514d8981 95 * @returns
AnnaBridge 156:ff21514d8981 96 * 0 on success (ack),
AnnaBridge 156:ff21514d8981 97 * non-0 on failure (nack)
AnnaBridge 156:ff21514d8981 98 */
AnnaBridge 156:ff21514d8981 99 int read(int address, char *data, int length, bool repeated = false);
AnnaBridge 156:ff21514d8981 100
AnnaBridge 156:ff21514d8981 101 /** Read a single byte from the I2C bus
AnnaBridge 156:ff21514d8981 102 *
AnnaBridge 156:ff21514d8981 103 * @param ack indicates if the byte is to be acknowledged (1 = acknowledge)
AnnaBridge 156:ff21514d8981 104 *
AnnaBridge 156:ff21514d8981 105 * @returns
AnnaBridge 156:ff21514d8981 106 * the byte read
AnnaBridge 156:ff21514d8981 107 */
AnnaBridge 156:ff21514d8981 108 int read(int ack);
AnnaBridge 156:ff21514d8981 109
AnnaBridge 156:ff21514d8981 110 /** Write to an I2C slave
AnnaBridge 156:ff21514d8981 111 *
AnnaBridge 156:ff21514d8981 112 * Performs a complete write transaction. The bottom bit of
AnnaBridge 156:ff21514d8981 113 * the address is forced to 0 to indicate a write.
AnnaBridge 156:ff21514d8981 114 *
AnnaBridge 156:ff21514d8981 115 * @param address 8-bit I2C slave address [ addr | 0 ]
AnnaBridge 156:ff21514d8981 116 * @param data Pointer to the byte-array data to send
AnnaBridge 156:ff21514d8981 117 * @param length Number of bytes to send
AnnaBridge 156:ff21514d8981 118 * @param repeated Repeated start, true - do not send stop at end
AnnaBridge 156:ff21514d8981 119 *
AnnaBridge 156:ff21514d8981 120 * @returns
AnnaBridge 156:ff21514d8981 121 * 0 on success (ack),
AnnaBridge 156:ff21514d8981 122 * non-0 on failure (nack)
AnnaBridge 156:ff21514d8981 123 */
AnnaBridge 156:ff21514d8981 124 int write(int address, const char *data, int length, bool repeated = false);
AnnaBridge 156:ff21514d8981 125
AnnaBridge 156:ff21514d8981 126 /** Write single byte out on the I2C bus
AnnaBridge 156:ff21514d8981 127 *
AnnaBridge 156:ff21514d8981 128 * @param data data to write out on bus
AnnaBridge 156:ff21514d8981 129 *
AnnaBridge 156:ff21514d8981 130 * @returns
AnnaBridge 156:ff21514d8981 131 * '0' - NAK was received
AnnaBridge 156:ff21514d8981 132 * '1' - ACK was received,
AnnaBridge 156:ff21514d8981 133 * '2' - timeout
AnnaBridge 156:ff21514d8981 134 */
AnnaBridge 156:ff21514d8981 135 int write(int data);
AnnaBridge 156:ff21514d8981 136
AnnaBridge 156:ff21514d8981 137 /** Creates a start condition on the I2C bus
AnnaBridge 156:ff21514d8981 138 */
AnnaBridge 156:ff21514d8981 139
AnnaBridge 156:ff21514d8981 140 void start(void);
AnnaBridge 156:ff21514d8981 141
AnnaBridge 156:ff21514d8981 142 /** Creates a stop condition on the I2C bus
AnnaBridge 156:ff21514d8981 143 */
AnnaBridge 156:ff21514d8981 144 void stop(void);
AnnaBridge 156:ff21514d8981 145
AnnaBridge 156:ff21514d8981 146 /** Acquire exclusive access to this I2C bus
AnnaBridge 156:ff21514d8981 147 */
AnnaBridge 156:ff21514d8981 148 virtual void lock(void);
AnnaBridge 156:ff21514d8981 149
AnnaBridge 156:ff21514d8981 150 /** Release exclusive access to this I2C bus
AnnaBridge 156:ff21514d8981 151 */
AnnaBridge 156:ff21514d8981 152 virtual void unlock(void);
AnnaBridge 156:ff21514d8981 153
AnnaBridge 156:ff21514d8981 154 virtual ~I2C() {
AnnaBridge 156:ff21514d8981 155 // Do nothing
AnnaBridge 156:ff21514d8981 156 }
AnnaBridge 156:ff21514d8981 157
AnnaBridge 156:ff21514d8981 158 #if DEVICE_I2C_ASYNCH
AnnaBridge 156:ff21514d8981 159
AnnaBridge 156:ff21514d8981 160 /** Start non-blocking I2C transfer.
AnnaBridge 156:ff21514d8981 161 *
AnnaBridge 156:ff21514d8981 162 * This function locks the deep sleep until any event has occured
AnnaBridge 156:ff21514d8981 163 *
AnnaBridge 156:ff21514d8981 164 * @param address 8/10 bit I2c slave address
AnnaBridge 156:ff21514d8981 165 * @param tx_buffer The TX buffer with data to be transfered
AnnaBridge 156:ff21514d8981 166 * @param tx_length The length of TX buffer in bytes
AnnaBridge 156:ff21514d8981 167 * @param rx_buffer The RX buffer which is used for received data
AnnaBridge 156:ff21514d8981 168 * @param rx_length The length of RX buffer in bytes
AnnaBridge 156:ff21514d8981 169 * @param event The logical OR of events to modify
AnnaBridge 156:ff21514d8981 170 * @param callback The event callback function
AnnaBridge 156:ff21514d8981 171 * @param repeated Repeated start, true - do not send stop at end
AnnaBridge 156:ff21514d8981 172 * @return Zero if the transfer has started, or -1 if I2C peripheral is busy
AnnaBridge 156:ff21514d8981 173 */
AnnaBridge 156:ff21514d8981 174 int transfer(int address, const char *tx_buffer, int tx_length, char *rx_buffer, int rx_length, const event_callback_t& callback, int event = I2C_EVENT_TRANSFER_COMPLETE, bool repeated = false);
AnnaBridge 156:ff21514d8981 175
AnnaBridge 156:ff21514d8981 176 /** Abort the on-going I2C transfer
AnnaBridge 156:ff21514d8981 177 */
AnnaBridge 156:ff21514d8981 178 void abort_transfer();
AnnaBridge 156:ff21514d8981 179 protected:
AnnaBridge 156:ff21514d8981 180 void irq_handler_asynch(void);
AnnaBridge 156:ff21514d8981 181 event_callback_t _callback;
AnnaBridge 156:ff21514d8981 182 CThunk<I2C> _irq;
AnnaBridge 156:ff21514d8981 183 DMAUsage _usage;
AnnaBridge 156:ff21514d8981 184 #endif
AnnaBridge 156:ff21514d8981 185
AnnaBridge 156:ff21514d8981 186 protected:
AnnaBridge 156:ff21514d8981 187 void aquire();
AnnaBridge 156:ff21514d8981 188
AnnaBridge 156:ff21514d8981 189 i2c_t _i2c;
AnnaBridge 156:ff21514d8981 190 static I2C *_owner;
AnnaBridge 156:ff21514d8981 191 int _hz;
AnnaBridge 156:ff21514d8981 192 static SingletonPtr<PlatformMutex> _mutex;
AnnaBridge 156:ff21514d8981 193 };
AnnaBridge 156:ff21514d8981 194
AnnaBridge 156:ff21514d8981 195 } // namespace mbed
AnnaBridge 156:ff21514d8981 196
AnnaBridge 156:ff21514d8981 197 #endif
AnnaBridge 156:ff21514d8981 198
AnnaBridge 156:ff21514d8981 199 #endif