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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@147:a97add6d7e64, 2017-07-19 (annotated)

Committer:
Kojto
Date:
Wed Jul 19 16:46:19 2017 +0100
Revision:
147:a97add6d7e64
Parent:
146:22da6e220af6
Child:
152:235179ab3f27
Release 147 of the mbed library.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
<> 128:9bcdf88f62b0 1 /* mbed Microcontroller Library
<> 128:9bcdf88f62b0 2 * Copyright (c) 2006-2015 ARM Limited
<> 128:9bcdf88f62b0 3 *
<> 128:9bcdf88f62b0 4 * Licensed under the Apache License, Version 2.0 (the "License");
<> 128:9bcdf88f62b0 5 * you may not use this file except in compliance with the License.
<> 128:9bcdf88f62b0 6 * You may obtain a copy of the License at
<> 128:9bcdf88f62b0 7 *
<> 128:9bcdf88f62b0 8 * http://www.apache.org/licenses/LICENSE-2.0
<> 128:9bcdf88f62b0 9 *
<> 128:9bcdf88f62b0 10 * Unless required by applicable law or agreed to in writing, software
<> 128:9bcdf88f62b0 11 * distributed under the License is distributed on an "AS IS" BASIS,
<> 128:9bcdf88f62b0 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
<> 128:9bcdf88f62b0 13 * See the License for the specific language governing permissions and
<> 128:9bcdf88f62b0 14 * limitations under the License.
<> 128:9bcdf88f62b0 15 */
<> 128:9bcdf88f62b0 16 #ifndef MBED_I2C_H
<> 128:9bcdf88f62b0 17 #define MBED_I2C_H
<> 128:9bcdf88f62b0 18
<> 128:9bcdf88f62b0 19 #include "platform/platform.h"
<> 128:9bcdf88f62b0 20
AnnaBridge 145:64910690c574 21 #if defined (DEVICE_I2C) || defined(DOXYGEN_ONLY)
<> 128:9bcdf88f62b0 22
<> 128:9bcdf88f62b0 23 #include "hal/i2c_api.h"
<> 128:9bcdf88f62b0 24 #include "platform/SingletonPtr.h"
<> 128:9bcdf88f62b0 25 #include "platform/PlatformMutex.h"
AnnaBridge 146:22da6e220af6 26 #include "platform/NonCopyable.h"
<> 128:9bcdf88f62b0 27
<> 128:9bcdf88f62b0 28 #if DEVICE_I2C_ASYNCH
<> 128:9bcdf88f62b0 29 #include "platform/CThunk.h"
<> 128:9bcdf88f62b0 30 #include "hal/dma_api.h"
<> 128:9bcdf88f62b0 31 #include "platform/FunctionPointer.h"
<> 128:9bcdf88f62b0 32 #endif
<> 128:9bcdf88f62b0 33
<> 128:9bcdf88f62b0 34 namespace mbed {
<> 128:9bcdf88f62b0 35 /** \addtogroup drivers */
<> 128:9bcdf88f62b0 36
<> 128:9bcdf88f62b0 37 /** An I2C Master, used for communicating with I2C slave devices
<> 128:9bcdf88f62b0 38 *
AnnaBridge 145:64910690c574 39 * @note Synchronization level: Thread safe
<> 128:9bcdf88f62b0 40 *
<> 128:9bcdf88f62b0 41 * Example:
<> 128:9bcdf88f62b0 42 * @code
<> 128:9bcdf88f62b0 43 * // Read from I2C slave at address 0x62
<> 128:9bcdf88f62b0 44 *
<> 128:9bcdf88f62b0 45 * #include "mbed.h"
<> 128:9bcdf88f62b0 46 *
<> 128:9bcdf88f62b0 47 * I2C i2c(p28, p27);
<> 128:9bcdf88f62b0 48 *
<> 128:9bcdf88f62b0 49 * int main() {
<> 128:9bcdf88f62b0 50 * int address = 0x62;
<> 128:9bcdf88f62b0 51 * char data[2];
<> 128:9bcdf88f62b0 52 * i2c.read(address, data, 2);
<> 128:9bcdf88f62b0 53 * }
<> 128:9bcdf88f62b0 54 * @endcode
AnnaBridge 145:64910690c574 55 * @ingroup drivers
<> 128:9bcdf88f62b0 56 */
AnnaBridge 146:22da6e220af6 57 class I2C : private NonCopyable<I2C> {
<> 128:9bcdf88f62b0 58
<> 128:9bcdf88f62b0 59 public:
<> 128:9bcdf88f62b0 60 enum RxStatus {
<> 128:9bcdf88f62b0 61 NoData,
<> 128:9bcdf88f62b0 62 MasterGeneralCall,
<> 128:9bcdf88f62b0 63 MasterWrite,
<> 128:9bcdf88f62b0 64 MasterRead
<> 128:9bcdf88f62b0 65 };
<> 128:9bcdf88f62b0 66
<> 128:9bcdf88f62b0 67 enum Acknowledge {
<> 128:9bcdf88f62b0 68 NoACK = 0,
<> 128:9bcdf88f62b0 69 ACK = 1
<> 128:9bcdf88f62b0 70 };
<> 128:9bcdf88f62b0 71
<> 128:9bcdf88f62b0 72 /** Create an I2C Master interface, connected to the specified pins
<> 128:9bcdf88f62b0 73 *
<> 128:9bcdf88f62b0 74 * @param sda I2C data line pin
<> 128:9bcdf88f62b0 75 * @param scl I2C clock line pin
<> 128:9bcdf88f62b0 76 */
<> 128:9bcdf88f62b0 77 I2C(PinName sda, PinName scl);
<> 128:9bcdf88f62b0 78
<> 128:9bcdf88f62b0 79 /** Set the frequency of the I2C interface
<> 128:9bcdf88f62b0 80 *
<> 128:9bcdf88f62b0 81 * @param hz The bus frequency in hertz
<> 128:9bcdf88f62b0 82 */
<> 128:9bcdf88f62b0 83 void frequency(int hz);
<> 128:9bcdf88f62b0 84
<> 128:9bcdf88f62b0 85 /** Read from an I2C slave
<> 128:9bcdf88f62b0 86 *
<> 128:9bcdf88f62b0 87 * Performs a complete read transaction. The bottom bit of
<> 128:9bcdf88f62b0 88 * the address is forced to 1 to indicate a read.
<> 128:9bcdf88f62b0 89 *
<> 128:9bcdf88f62b0 90 * @param address 8-bit I2C slave address [ addr | 1 ]
<> 128:9bcdf88f62b0 91 * @param data Pointer to the byte-array to read data in to
<> 128:9bcdf88f62b0 92 * @param length Number of bytes to read
<> 128:9bcdf88f62b0 93 * @param repeated Repeated start, true - don't send stop at end
<> 128:9bcdf88f62b0 94 *
<> 128:9bcdf88f62b0 95 * @returns
<> 128:9bcdf88f62b0 96 * 0 on success (ack),
<> 128:9bcdf88f62b0 97 * non-0 on failure (nack)
<> 128:9bcdf88f62b0 98 */
<> 128:9bcdf88f62b0 99 int read(int address, char *data, int length, bool repeated = false);
<> 128:9bcdf88f62b0 100
<> 128:9bcdf88f62b0 101 /** Read a single byte from the I2C bus
<> 128:9bcdf88f62b0 102 *
<> 128:9bcdf88f62b0 103 * @param ack indicates if the byte is to be acknowledged (1 = acknowledge)
<> 128:9bcdf88f62b0 104 *
<> 128:9bcdf88f62b0 105 * @returns
<> 128:9bcdf88f62b0 106 * the byte read
<> 128:9bcdf88f62b0 107 */
<> 128:9bcdf88f62b0 108 int read(int ack);
<> 128:9bcdf88f62b0 109
<> 128:9bcdf88f62b0 110 /** Write to an I2C slave
<> 128:9bcdf88f62b0 111 *
<> 128:9bcdf88f62b0 112 * Performs a complete write transaction. The bottom bit of
<> 128:9bcdf88f62b0 113 * the address is forced to 0 to indicate a write.
<> 128:9bcdf88f62b0 114 *
<> 128:9bcdf88f62b0 115 * @param address 8-bit I2C slave address [ addr | 0 ]
<> 128:9bcdf88f62b0 116 * @param data Pointer to the byte-array data to send
<> 128:9bcdf88f62b0 117 * @param length Number of bytes to send
<> 128:9bcdf88f62b0 118 * @param repeated Repeated start, true - do not send stop at end
<> 128:9bcdf88f62b0 119 *
<> 128:9bcdf88f62b0 120 * @returns
<> 139:856d2700e60b 121 * 0 on success (ack),
<> 139:856d2700e60b 122 * non-0 on failure (nack)
<> 128:9bcdf88f62b0 123 */
<> 128:9bcdf88f62b0 124 int write(int address, const char *data, int length, bool repeated = false);
<> 128:9bcdf88f62b0 125
<> 128:9bcdf88f62b0 126 /** Write single byte out on the I2C bus
<> 128:9bcdf88f62b0 127 *
<> 128:9bcdf88f62b0 128 * @param data data to write out on bus
<> 128:9bcdf88f62b0 129 *
<> 128:9bcdf88f62b0 130 * @returns
<> 132:9baf128c2fab 131 * '0' - NAK was received
<> 132:9baf128c2fab 132 * '1' - ACK was received,
<> 132:9baf128c2fab 133 * '2' - timeout
<> 128:9bcdf88f62b0 134 */
<> 128:9bcdf88f62b0 135 int write(int data);
<> 128:9bcdf88f62b0 136
<> 128:9bcdf88f62b0 137 /** Creates a start condition on the I2C bus
<> 128:9bcdf88f62b0 138 */
<> 128:9bcdf88f62b0 139
<> 128:9bcdf88f62b0 140 void start(void);
<> 128:9bcdf88f62b0 141
<> 128:9bcdf88f62b0 142 /** Creates a stop condition on the I2C bus
<> 128:9bcdf88f62b0 143 */
<> 128:9bcdf88f62b0 144 void stop(void);
<> 128:9bcdf88f62b0 145
<> 128:9bcdf88f62b0 146 /** Acquire exclusive access to this I2C bus
<> 128:9bcdf88f62b0 147 */
<> 128:9bcdf88f62b0 148 virtual void lock(void);
<> 128:9bcdf88f62b0 149
<> 128:9bcdf88f62b0 150 /** Release exclusive access to this I2C bus
<> 128:9bcdf88f62b0 151 */
<> 128:9bcdf88f62b0 152 virtual void unlock(void);
<> 128:9bcdf88f62b0 153
<> 128:9bcdf88f62b0 154 virtual ~I2C() {
<> 128:9bcdf88f62b0 155 // Do nothing
<> 128:9bcdf88f62b0 156 }
<> 128:9bcdf88f62b0 157
<> 128:9bcdf88f62b0 158 #if DEVICE_I2C_ASYNCH
<> 128:9bcdf88f62b0 159
<> 128:9bcdf88f62b0 160 /** Start non-blocking I2C transfer.
<> 128:9bcdf88f62b0 161 *
<> 128:9bcdf88f62b0 162 * @param address 8/10 bit I2c slave address
<> 128:9bcdf88f62b0 163 * @param tx_buffer The TX buffer with data to be transfered
<> 128:9bcdf88f62b0 164 * @param tx_length The length of TX buffer in bytes
<> 128:9bcdf88f62b0 165 * @param rx_buffer The RX buffer which is used for received data
<> 128:9bcdf88f62b0 166 * @param rx_length The length of RX buffer in bytes
<> 128:9bcdf88f62b0 167 * @param event The logical OR of events to modify
<> 128:9bcdf88f62b0 168 * @param callback The event callback function
<> 128:9bcdf88f62b0 169 * @param repeated Repeated start, true - do not send stop at end
<> 128:9bcdf88f62b0 170 * @return Zero if the transfer has started, or -1 if I2C peripheral is busy
<> 128:9bcdf88f62b0 171 */
<> 128:9bcdf88f62b0 172 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);
<> 128:9bcdf88f62b0 173
<> 128:9bcdf88f62b0 174 /** Abort the on-going I2C transfer
<> 128:9bcdf88f62b0 175 */
<> 128:9bcdf88f62b0 176 void abort_transfer();
<> 128:9bcdf88f62b0 177 protected:
<> 128:9bcdf88f62b0 178 void irq_handler_asynch(void);
<> 128:9bcdf88f62b0 179 event_callback_t _callback;
<> 128:9bcdf88f62b0 180 CThunk<I2C> _irq;
<> 128:9bcdf88f62b0 181 DMAUsage _usage;
<> 128:9bcdf88f62b0 182 #endif
<> 128:9bcdf88f62b0 183
<> 128:9bcdf88f62b0 184 protected:
<> 128:9bcdf88f62b0 185 void aquire();
<> 128:9bcdf88f62b0 186
<> 128:9bcdf88f62b0 187 i2c_t _i2c;
<> 128:9bcdf88f62b0 188 static I2C *_owner;
<> 128:9bcdf88f62b0 189 int _hz;
<> 128:9bcdf88f62b0 190 static SingletonPtr<PlatformMutex> _mutex;
<> 128:9bcdf88f62b0 191 };
<> 128:9bcdf88f62b0 192
<> 128:9bcdf88f62b0 193 } // namespace mbed
<> 128:9bcdf88f62b0 194
<> 128:9bcdf88f62b0 195 #endif
<> 128:9bcdf88f62b0 196
<> 128:9bcdf88f62b0 197 #endif