kushagra brahmbhatt / IoT_Security

IoT Home Alarm System

Dependents:   IoTBurglar_and_Fire_AlarmSystem

I2CSlave.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_SLAVE_H
kbrahmbhatt6 0:2f388b030837 17 #define MBED_I2C_SLAVE_H
kbrahmbhatt6 0:2f388b030837 18
kbrahmbhatt6 0:2f388b030837 19 #include "platform.h"
kbrahmbhatt6 0:2f388b030837 20
kbrahmbhatt6 0:2f388b030837 21 #if DEVICE_I2CSLAVE
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 Slave, used for communicating with an I2C Master device
kbrahmbhatt6 0:2f388b030837 28 *
kbrahmbhatt6 0:2f388b030837 29 * Example:
kbrahmbhatt6 0:2f388b030837 30 * @code
kbrahmbhatt6 0:2f388b030837 31 * // Simple I2C responder
kbrahmbhatt6 0:2f388b030837 32 * #include <mbed.h>
kbrahmbhatt6 0:2f388b030837 33 *
kbrahmbhatt6 0:2f388b030837 34 * I2CSlave slave(p9, p10);
kbrahmbhatt6 0:2f388b030837 35 *
kbrahmbhatt6 0:2f388b030837 36 * int main() {
kbrahmbhatt6 0:2f388b030837 37 * char buf[10];
kbrahmbhatt6 0:2f388b030837 38 * char msg[] = "Slave!";
kbrahmbhatt6 0:2f388b030837 39 *
kbrahmbhatt6 0:2f388b030837 40 * slave.address(0xA0);
kbrahmbhatt6 0:2f388b030837 41 * while (1) {
kbrahmbhatt6 0:2f388b030837 42 * int i = slave.receive();
kbrahmbhatt6 0:2f388b030837 43 * switch (i) {
kbrahmbhatt6 0:2f388b030837 44 * case I2CSlave::ReadAddressed:
kbrahmbhatt6 0:2f388b030837 45 * slave.write(msg, strlen(msg) + 1); // Includes null char
kbrahmbhatt6 0:2f388b030837 46 * break;
kbrahmbhatt6 0:2f388b030837 47 * case I2CSlave::WriteGeneral:
kbrahmbhatt6 0:2f388b030837 48 * slave.read(buf, 10);
kbrahmbhatt6 0:2f388b030837 49 * printf("Read G: %s\n", buf);
kbrahmbhatt6 0:2f388b030837 50 * break;
kbrahmbhatt6 0:2f388b030837 51 * case I2CSlave::WriteAddressed:
kbrahmbhatt6 0:2f388b030837 52 * slave.read(buf, 10);
kbrahmbhatt6 0:2f388b030837 53 * printf("Read A: %s\n", buf);
kbrahmbhatt6 0:2f388b030837 54 * break;
kbrahmbhatt6 0:2f388b030837 55 * }
kbrahmbhatt6 0:2f388b030837 56 * for(int i = 0; i < 10; i++) buf[i] = 0; // Clear buffer
kbrahmbhatt6 0:2f388b030837 57 * }
kbrahmbhatt6 0:2f388b030837 58 * }
kbrahmbhatt6 0:2f388b030837 59 * @endcode
kbrahmbhatt6 0:2f388b030837 60 */
kbrahmbhatt6 0:2f388b030837 61 class I2CSlave {
kbrahmbhatt6 0:2f388b030837 62
kbrahmbhatt6 0:2f388b030837 63 public:
kbrahmbhatt6 0:2f388b030837 64 enum RxStatus {
kbrahmbhatt6 0:2f388b030837 65 NoData = 0,
kbrahmbhatt6 0:2f388b030837 66 ReadAddressed = 1,
kbrahmbhatt6 0:2f388b030837 67 WriteGeneral = 2,
kbrahmbhatt6 0:2f388b030837 68 WriteAddressed = 3
kbrahmbhatt6 0:2f388b030837 69 };
kbrahmbhatt6 0:2f388b030837 70
kbrahmbhatt6 0:2f388b030837 71 /** Create an I2C Slave interface, connected to the specified pins.
kbrahmbhatt6 0:2f388b030837 72 *
kbrahmbhatt6 0:2f388b030837 73 * @param sda I2C data line pin
kbrahmbhatt6 0:2f388b030837 74 * @param scl I2C clock line pin
kbrahmbhatt6 0:2f388b030837 75 */
kbrahmbhatt6 0:2f388b030837 76 I2CSlave(PinName sda, PinName scl);
kbrahmbhatt6 0:2f388b030837 77
kbrahmbhatt6 0:2f388b030837 78 /** Set the frequency of the I2C interface
kbrahmbhatt6 0:2f388b030837 79 *
kbrahmbhatt6 0:2f388b030837 80 * @param hz The bus frequency in hertz
kbrahmbhatt6 0:2f388b030837 81 */
kbrahmbhatt6 0:2f388b030837 82 void frequency(int hz);
kbrahmbhatt6 0:2f388b030837 83
kbrahmbhatt6 0:2f388b030837 84 /** Checks to see if this I2C Slave has been addressed.
kbrahmbhatt6 0:2f388b030837 85 *
kbrahmbhatt6 0:2f388b030837 86 * @returns
kbrahmbhatt6 0:2f388b030837 87 * A status indicating if the device has been addressed, and how
kbrahmbhatt6 0:2f388b030837 88 * - NoData - the slave has not been addressed
kbrahmbhatt6 0:2f388b030837 89 * - ReadAddressed - the master has requested a read from this slave
kbrahmbhatt6 0:2f388b030837 90 * - WriteAddressed - the master is writing to this slave
kbrahmbhatt6 0:2f388b030837 91 * - WriteGeneral - the master is writing to all slave
kbrahmbhatt6 0:2f388b030837 92 */
kbrahmbhatt6 0:2f388b030837 93 int receive(void);
kbrahmbhatt6 0:2f388b030837 94
kbrahmbhatt6 0:2f388b030837 95 /** Read from an I2C master.
kbrahmbhatt6 0:2f388b030837 96 *
kbrahmbhatt6 0:2f388b030837 97 * @param data pointer to the byte array to read data in to
kbrahmbhatt6 0:2f388b030837 98 * @param length maximum number of bytes to read
kbrahmbhatt6 0:2f388b030837 99 *
kbrahmbhatt6 0:2f388b030837 100 * @returns
kbrahmbhatt6 0:2f388b030837 101 * 0 on success,
kbrahmbhatt6 0:2f388b030837 102 * non-0 otherwise
kbrahmbhatt6 0:2f388b030837 103 */
kbrahmbhatt6 0:2f388b030837 104 int read(char *data, int length);
kbrahmbhatt6 0:2f388b030837 105
kbrahmbhatt6 0:2f388b030837 106 /** Read a single byte from an I2C master.
kbrahmbhatt6 0:2f388b030837 107 *
kbrahmbhatt6 0:2f388b030837 108 * @returns
kbrahmbhatt6 0:2f388b030837 109 * the byte read
kbrahmbhatt6 0:2f388b030837 110 */
kbrahmbhatt6 0:2f388b030837 111 int read(void);
kbrahmbhatt6 0:2f388b030837 112
kbrahmbhatt6 0:2f388b030837 113 /** Write to an I2C master.
kbrahmbhatt6 0:2f388b030837 114 *
kbrahmbhatt6 0:2f388b030837 115 * @param data pointer to the byte array to be transmitted
kbrahmbhatt6 0:2f388b030837 116 * @param length the number of bytes to transmite
kbrahmbhatt6 0:2f388b030837 117 *
kbrahmbhatt6 0:2f388b030837 118 * @returns
kbrahmbhatt6 0:2f388b030837 119 * 0 on success,
kbrahmbhatt6 0:2f388b030837 120 * non-0 otherwise
kbrahmbhatt6 0:2f388b030837 121 */
kbrahmbhatt6 0:2f388b030837 122 int write(const char *data, int length);
kbrahmbhatt6 0:2f388b030837 123
kbrahmbhatt6 0:2f388b030837 124 /** Write a single byte to an I2C master.
kbrahmbhatt6 0:2f388b030837 125 *
kbrahmbhatt6 0:2f388b030837 126 * @data the byte to write
kbrahmbhatt6 0:2f388b030837 127 *
kbrahmbhatt6 0:2f388b030837 128 * @returns
kbrahmbhatt6 0:2f388b030837 129 * '1' if an ACK was received,
kbrahmbhatt6 0:2f388b030837 130 * '0' otherwise
kbrahmbhatt6 0:2f388b030837 131 */
kbrahmbhatt6 0:2f388b030837 132 int write(int data);
kbrahmbhatt6 0:2f388b030837 133
kbrahmbhatt6 0:2f388b030837 134 /** Sets the I2C slave address.
kbrahmbhatt6 0:2f388b030837 135 *
kbrahmbhatt6 0:2f388b030837 136 * @param address The address to set for the slave (ignoring the least
kbrahmbhatt6 0:2f388b030837 137 * signifcant bit). If set to 0, the slave will only respond to the
kbrahmbhatt6 0:2f388b030837 138 * general call address.
kbrahmbhatt6 0:2f388b030837 139 */
kbrahmbhatt6 0:2f388b030837 140 void address(int address);
kbrahmbhatt6 0:2f388b030837 141
kbrahmbhatt6 0:2f388b030837 142 /** Reset the I2C slave back into the known ready receiving state.
kbrahmbhatt6 0:2f388b030837 143 */
kbrahmbhatt6 0:2f388b030837 144 void stop(void);
kbrahmbhatt6 0:2f388b030837 145
kbrahmbhatt6 0:2f388b030837 146 protected:
kbrahmbhatt6 0:2f388b030837 147 i2c_t _i2c;
kbrahmbhatt6 0:2f388b030837 148 };
kbrahmbhatt6 0:2f388b030837 149
kbrahmbhatt6 0:2f388b030837 150 } // namespace mbed
kbrahmbhatt6 0:2f388b030837 151
kbrahmbhatt6 0:2f388b030837 152 #endif
kbrahmbhatt6 0:2f388b030837 153
kbrahmbhatt6 0:2f388b030837 154 #endif