kushagra brahmbhatt / IoT_Security

IoT Home Alarm System

Dependents:   IoTBurglar_and_Fire_AlarmSystem

I2C.h@0:2f388b030837, 2016-04-29 (annotated)

Committer:
kbrahmbhatt6
Date:
Fri Apr 29 06:59:59 2016 +0000
Revision:
0:2f388b030837
1

Who changed what in which revision?

UserRevisionLine numberNew contents of line
kbrahmbhatt6 0:2f388b030837 1 /* mbed Microcontroller Library
kbrahmbhatt6 0:2f388b030837 2 * Copyright (c) 2006-2013 ARM Limited
kbrahmbhatt6 0:2f388b030837 3 *
kbrahmbhatt6 0:2f388b030837 4 * Licensed under the Apache License, Version 2.0 (the "License");
kbrahmbhatt6 0:2f388b030837 5 * you may not use this file except in compliance with the License.
kbrahmbhatt6 0:2f388b030837 6 * You may obtain a copy of the License at
kbrahmbhatt6 0:2f388b030837 7 *
kbrahmbhatt6 0:2f388b030837 8 * http://www.apache.org/licenses/LICENSE-2.0
kbrahmbhatt6 0:2f388b030837 9 *
kbrahmbhatt6 0:2f388b030837 10 * Unless required by applicable law or agreed to in writing, software
kbrahmbhatt6 0:2f388b030837 11 * distributed under the License is distributed on an "AS IS" BASIS,
kbrahmbhatt6 0:2f388b030837 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
kbrahmbhatt6 0:2f388b030837 13 * See the License for the specific language governing permissions and
kbrahmbhatt6 0:2f388b030837 14 * limitations under the License.
kbrahmbhatt6 0:2f388b030837 15 */
kbrahmbhatt6 0:2f388b030837 16 #ifndef MBED_I2C_H
kbrahmbhatt6 0:2f388b030837 17 #define MBED_I2C_H
kbrahmbhatt6 0:2f388b030837 18
kbrahmbhatt6 0:2f388b030837 19 #include "platform.h"
kbrahmbhatt6 0:2f388b030837 20
kbrahmbhatt6 0:2f388b030837 21 #if DEVICE_I2C
kbrahmbhatt6 0:2f388b030837 22
kbrahmbhatt6 0:2f388b030837 23 #include "i2c_api.h"
kbrahmbhatt6 0:2f388b030837 24
kbrahmbhatt6 0:2f388b030837 25 namespace mbed {
kbrahmbhatt6 0:2f388b030837 26
kbrahmbhatt6 0:2f388b030837 27 /** An I2C Master, used for communicating with I2C slave devices
kbrahmbhatt6 0:2f388b030837 28 *
kbrahmbhatt6 0:2f388b030837 29 * Example:
kbrahmbhatt6 0:2f388b030837 30 * @code
kbrahmbhatt6 0:2f388b030837 31 * // Read from I2C slave at address 0x62
kbrahmbhatt6 0:2f388b030837 32 *
kbrahmbhatt6 0:2f388b030837 33 * #include "mbed.h"
kbrahmbhatt6 0:2f388b030837 34 *
kbrahmbhatt6 0:2f388b030837 35 * I2C i2c(p28, p27);
kbrahmbhatt6 0:2f388b030837 36 *
kbrahmbhatt6 0:2f388b030837 37 * int main() {
kbrahmbhatt6 0:2f388b030837 38 * int address = 0x62;
kbrahmbhatt6 0:2f388b030837 39 * char data[2];
kbrahmbhatt6 0:2f388b030837 40 * i2c.read(address, data, 2);
kbrahmbhatt6 0:2f388b030837 41 * }
kbrahmbhatt6 0:2f388b030837 42 * @endcode
kbrahmbhatt6 0:2f388b030837 43 */
kbrahmbhatt6 0:2f388b030837 44 class I2C {
kbrahmbhatt6 0:2f388b030837 45
kbrahmbhatt6 0:2f388b030837 46 public:
kbrahmbhatt6 0:2f388b030837 47 enum RxStatus {
kbrahmbhatt6 0:2f388b030837 48 NoData,
kbrahmbhatt6 0:2f388b030837 49 MasterGeneralCall,
kbrahmbhatt6 0:2f388b030837 50 MasterWrite,
kbrahmbhatt6 0:2f388b030837 51 MasterRead
kbrahmbhatt6 0:2f388b030837 52 };
kbrahmbhatt6 0:2f388b030837 53
kbrahmbhatt6 0:2f388b030837 54 enum Acknowledge {
kbrahmbhatt6 0:2f388b030837 55 NoACK = 0,
kbrahmbhatt6 0:2f388b030837 56 ACK = 1
kbrahmbhatt6 0:2f388b030837 57 };
kbrahmbhatt6 0:2f388b030837 58
kbrahmbhatt6 0:2f388b030837 59 /** Create an I2C Master interface, connected to the specified pins
kbrahmbhatt6 0:2f388b030837 60 *
kbrahmbhatt6 0:2f388b030837 61 * @param sda I2C data line pin
kbrahmbhatt6 0:2f388b030837 62 * @param scl I2C clock line pin
kbrahmbhatt6 0:2f388b030837 63 */
kbrahmbhatt6 0:2f388b030837 64 I2C(PinName sda, PinName scl);
kbrahmbhatt6 0:2f388b030837 65
kbrahmbhatt6 0:2f388b030837 66 /** Set the frequency of the I2C interface
kbrahmbhatt6 0:2f388b030837 67 *
kbrahmbhatt6 0:2f388b030837 68 * @param hz The bus frequency in hertz
kbrahmbhatt6 0:2f388b030837 69 */
kbrahmbhatt6 0:2f388b030837 70 void frequency(int hz);
kbrahmbhatt6 0:2f388b030837 71
kbrahmbhatt6 0:2f388b030837 72 /** Read from an I2C slave
kbrahmbhatt6 0:2f388b030837 73 *
kbrahmbhatt6 0:2f388b030837 74 * Performs a complete read transaction. The bottom bit of
kbrahmbhatt6 0:2f388b030837 75 * the address is forced to 1 to indicate a read.
kbrahmbhatt6 0:2f388b030837 76 *
kbrahmbhatt6 0:2f388b030837 77 * @param address 8-bit I2C slave address [ addr | 1 ]
kbrahmbhatt6 0:2f388b030837 78 * @param data Pointer to the byte-array to read data in to
kbrahmbhatt6 0:2f388b030837 79 * @param length Number of bytes to read
kbrahmbhatt6 0:2f388b030837 80 * @param repeated Repeated start, true - don't send stop at end
kbrahmbhatt6 0:2f388b030837 81 *
kbrahmbhatt6 0:2f388b030837 82 * @returns
kbrahmbhatt6 0:2f388b030837 83 * 0 on success (ack),
kbrahmbhatt6 0:2f388b030837 84 * non-0 on failure (nack)
kbrahmbhatt6 0:2f388b030837 85 */
kbrahmbhatt6 0:2f388b030837 86 int read(int address, char *data, int length, bool repeated = false);
kbrahmbhatt6 0:2f388b030837 87
kbrahmbhatt6 0:2f388b030837 88 /** Read a single byte from the I2C bus
kbrahmbhatt6 0:2f388b030837 89 *
kbrahmbhatt6 0:2f388b030837 90 * @param ack indicates if the byte is to be acknowledged (1 = acknowledge)
kbrahmbhatt6 0:2f388b030837 91 *
kbrahmbhatt6 0:2f388b030837 92 * @returns
kbrahmbhatt6 0:2f388b030837 93 * the byte read
kbrahmbhatt6 0:2f388b030837 94 */
kbrahmbhatt6 0:2f388b030837 95 int read(int ack);
kbrahmbhatt6 0:2f388b030837 96
kbrahmbhatt6 0:2f388b030837 97 /** Write to an I2C slave
kbrahmbhatt6 0:2f388b030837 98 *
kbrahmbhatt6 0:2f388b030837 99 * Performs a complete write transaction. The bottom bit of
kbrahmbhatt6 0:2f388b030837 100 * the address is forced to 0 to indicate a write.
kbrahmbhatt6 0:2f388b030837 101 *
kbrahmbhatt6 0:2f388b030837 102 * @param address 8-bit I2C slave address [ addr | 0 ]
kbrahmbhatt6 0:2f388b030837 103 * @param data Pointer to the byte-array data to send
kbrahmbhatt6 0:2f388b030837 104 * @param length Number of bytes to send
kbrahmbhatt6 0:2f388b030837 105 * @param repeated Repeated start, true - do not send stop at end
kbrahmbhatt6 0:2f388b030837 106 *
kbrahmbhatt6 0:2f388b030837 107 * @returns
kbrahmbhatt6 0:2f388b030837 108 * 0 on success (ack),
kbrahmbhatt6 0:2f388b030837 109 * non-0 on failure (nack)
kbrahmbhatt6 0:2f388b030837 110 */
kbrahmbhatt6 0:2f388b030837 111 int write(int address, const char *data, int length, bool repeated = false);
kbrahmbhatt6 0:2f388b030837 112
kbrahmbhatt6 0:2f388b030837 113 /** Write single byte out on the I2C bus
kbrahmbhatt6 0:2f388b030837 114 *
kbrahmbhatt6 0:2f388b030837 115 * @param data data to write out on bus
kbrahmbhatt6 0:2f388b030837 116 *
kbrahmbhatt6 0:2f388b030837 117 * @returns
kbrahmbhatt6 0:2f388b030837 118 * '1' if an ACK was received,
kbrahmbhatt6 0:2f388b030837 119 * '0' otherwise
kbrahmbhatt6 0:2f388b030837 120 */
kbrahmbhatt6 0:2f388b030837 121 int write(int data);
kbrahmbhatt6 0:2f388b030837 122
kbrahmbhatt6 0:2f388b030837 123 /** Creates a start condition on the I2C bus
kbrahmbhatt6 0:2f388b030837 124 */
kbrahmbhatt6 0:2f388b030837 125
kbrahmbhatt6 0:2f388b030837 126 void start(void);
kbrahmbhatt6 0:2f388b030837 127
kbrahmbhatt6 0:2f388b030837 128 /** Creates a stop condition on the I2C bus
kbrahmbhatt6 0:2f388b030837 129 */
kbrahmbhatt6 0:2f388b030837 130 void stop(void);
kbrahmbhatt6 0:2f388b030837 131
kbrahmbhatt6 0:2f388b030837 132 protected:
kbrahmbhatt6 0:2f388b030837 133 void aquire();
kbrahmbhatt6 0:2f388b030837 134
kbrahmbhatt6 0:2f388b030837 135 i2c_t _i2c;
kbrahmbhatt6 0:2f388b030837 136 static I2C *_owner;
kbrahmbhatt6 0:2f388b030837 137 int _hz;
kbrahmbhatt6 0:2f388b030837 138 };
kbrahmbhatt6 0:2f388b030837 139
kbrahmbhatt6 0:2f388b030837 140 } // namespace mbed
kbrahmbhatt6 0:2f388b030837 141
kbrahmbhatt6 0:2f388b030837 142 #endif
kbrahmbhatt6 0:2f388b030837 143
kbrahmbhatt6 0:2f388b030837 144 #endif