teralytic / mbed-dev

mbed library sources. Supersedes mbed-src.

Fork of mbed by teralytic

api/I2CSlave.h@148:4802eb17e82b, 2016-10-17 (annotated)

Committer:
rodriguise
Date:
Mon Oct 17 18:47:01 2016 +0000
Revision:
148:4802eb17e82b
Parent:
144:ef7eb2e8f9f7 
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<> 144:ef7eb2e8f9f7 1 /* mbed Microcontroller Library
<> 144:ef7eb2e8f9f7 2 * Copyright (c) 2006-2013 ARM Limited
<> 144:ef7eb2e8f9f7 3 *
<> 144:ef7eb2e8f9f7 4 * Licensed under the Apache License, Version 2.0 (the "License");
<> 144:ef7eb2e8f9f7 5 * you may not use this file except in compliance with the License.
<> 144:ef7eb2e8f9f7 6 * You may obtain a copy of the License at
<> 144:ef7eb2e8f9f7 7 *
<> 144:ef7eb2e8f9f7 8 * http://www.apache.org/licenses/LICENSE-2.0
<> 144:ef7eb2e8f9f7 9 *
<> 144:ef7eb2e8f9f7 10 * Unless required by applicable law or agreed to in writing, software
<> 144:ef7eb2e8f9f7 11 * distributed under the License is distributed on an "AS IS" BASIS,
<> 144:ef7eb2e8f9f7 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
<> 144:ef7eb2e8f9f7 13 * See the License for the specific language governing permissions and
<> 144:ef7eb2e8f9f7 14 * limitations under the License.
<> 144:ef7eb2e8f9f7 15 */
<> 144:ef7eb2e8f9f7 16 #ifndef MBED_I2C_SLAVE_H
<> 144:ef7eb2e8f9f7 17 #define MBED_I2C_SLAVE_H
<> 144:ef7eb2e8f9f7 18
<> 144:ef7eb2e8f9f7 19 #include "platform.h"
<> 144:ef7eb2e8f9f7 20
<> 144:ef7eb2e8f9f7 21 #if DEVICE_I2CSLAVE
<> 144:ef7eb2e8f9f7 22
<> 144:ef7eb2e8f9f7 23 #include "i2c_api.h"
<> 144:ef7eb2e8f9f7 24
<> 144:ef7eb2e8f9f7 25 namespace mbed {
<> 144:ef7eb2e8f9f7 26
<> 144:ef7eb2e8f9f7 27 /** An I2C Slave, used for communicating with an I2C Master device
<> 144:ef7eb2e8f9f7 28 *
<> 144:ef7eb2e8f9f7 29 * @Note Synchronization level: Not protected
<> 144:ef7eb2e8f9f7 30 *
<> 144:ef7eb2e8f9f7 31 * Example:
<> 144:ef7eb2e8f9f7 32 * @code
<> 144:ef7eb2e8f9f7 33 * // Simple I2C responder
<> 144:ef7eb2e8f9f7 34 * #include <mbed.h>
<> 144:ef7eb2e8f9f7 35 *
<> 144:ef7eb2e8f9f7 36 * I2CSlave slave(p9, p10);
<> 144:ef7eb2e8f9f7 37 *
<> 144:ef7eb2e8f9f7 38 * int main() {
<> 144:ef7eb2e8f9f7 39 * char buf[10];
<> 144:ef7eb2e8f9f7 40 * char msg[] = "Slave!";
<> 144:ef7eb2e8f9f7 41 *
<> 144:ef7eb2e8f9f7 42 * slave.address(0xA0);
<> 144:ef7eb2e8f9f7 43 * while (1) {
<> 144:ef7eb2e8f9f7 44 * int i = slave.receive();
<> 144:ef7eb2e8f9f7 45 * switch (i) {
<> 144:ef7eb2e8f9f7 46 * case I2CSlave::ReadAddressed:
<> 144:ef7eb2e8f9f7 47 * slave.write(msg, strlen(msg) + 1); // Includes null char
<> 144:ef7eb2e8f9f7 48 * break;
<> 144:ef7eb2e8f9f7 49 * case I2CSlave::WriteGeneral:
<> 144:ef7eb2e8f9f7 50 * slave.read(buf, 10);
<> 144:ef7eb2e8f9f7 51 * printf("Read G: %s\n", buf);
<> 144:ef7eb2e8f9f7 52 * break;
<> 144:ef7eb2e8f9f7 53 * case I2CSlave::WriteAddressed:
<> 144:ef7eb2e8f9f7 54 * slave.read(buf, 10);
<> 144:ef7eb2e8f9f7 55 * printf("Read A: %s\n", buf);
<> 144:ef7eb2e8f9f7 56 * break;
<> 144:ef7eb2e8f9f7 57 * }
<> 144:ef7eb2e8f9f7 58 * for(int i = 0; i < 10; i++) buf[i] = 0; // Clear buffer
<> 144:ef7eb2e8f9f7 59 * }
<> 144:ef7eb2e8f9f7 60 * }
<> 144:ef7eb2e8f9f7 61 * @endcode
<> 144:ef7eb2e8f9f7 62 */
<> 144:ef7eb2e8f9f7 63 class I2CSlave {
<> 144:ef7eb2e8f9f7 64
<> 144:ef7eb2e8f9f7 65 public:
<> 144:ef7eb2e8f9f7 66 enum RxStatus {
<> 144:ef7eb2e8f9f7 67 NoData = 0,
<> 144:ef7eb2e8f9f7 68 ReadAddressed = 1,
<> 144:ef7eb2e8f9f7 69 WriteGeneral = 2,
<> 144:ef7eb2e8f9f7 70 WriteAddressed = 3
<> 144:ef7eb2e8f9f7 71 };
<> 144:ef7eb2e8f9f7 72
<> 144:ef7eb2e8f9f7 73 /** Create an I2C Slave interface, connected to the specified pins.
<> 144:ef7eb2e8f9f7 74 *
<> 144:ef7eb2e8f9f7 75 * @param sda I2C data line pin
<> 144:ef7eb2e8f9f7 76 * @param scl I2C clock line pin
<> 144:ef7eb2e8f9f7 77 */
<> 144:ef7eb2e8f9f7 78 I2CSlave(PinName sda, PinName scl);
<> 144:ef7eb2e8f9f7 79
<> 144:ef7eb2e8f9f7 80 /** Set the frequency of the I2C interface
<> 144:ef7eb2e8f9f7 81 *
<> 144:ef7eb2e8f9f7 82 * @param hz The bus frequency in hertz
<> 144:ef7eb2e8f9f7 83 */
<> 144:ef7eb2e8f9f7 84 void frequency(int hz);
<> 144:ef7eb2e8f9f7 85
<> 144:ef7eb2e8f9f7 86 /** Checks to see if this I2C Slave has been addressed.
<> 144:ef7eb2e8f9f7 87 *
<> 144:ef7eb2e8f9f7 88 * @returns
<> 144:ef7eb2e8f9f7 89 * A status indicating if the device has been addressed, and how
<> 144:ef7eb2e8f9f7 90 * - NoData - the slave has not been addressed
<> 144:ef7eb2e8f9f7 91 * - ReadAddressed - the master has requested a read from this slave
<> 144:ef7eb2e8f9f7 92 * - WriteAddressed - the master is writing to this slave
<> 144:ef7eb2e8f9f7 93 * - WriteGeneral - the master is writing to all slave
<> 144:ef7eb2e8f9f7 94 */
<> 144:ef7eb2e8f9f7 95 int receive(void);
<> 144:ef7eb2e8f9f7 96
<> 144:ef7eb2e8f9f7 97 /** Read from an I2C master.
<> 144:ef7eb2e8f9f7 98 *
<> 144:ef7eb2e8f9f7 99 * @param data pointer to the byte array to read data in to
<> 144:ef7eb2e8f9f7 100 * @param length maximum number of bytes to read
<> 144:ef7eb2e8f9f7 101 *
<> 144:ef7eb2e8f9f7 102 * @returns
<> 144:ef7eb2e8f9f7 103 * 0 on success,
<> 144:ef7eb2e8f9f7 104 * non-0 otherwise
<> 144:ef7eb2e8f9f7 105 */
<> 144:ef7eb2e8f9f7 106 int read(char *data, int length);
<> 144:ef7eb2e8f9f7 107
<> 144:ef7eb2e8f9f7 108 /** Read a single byte from an I2C master.
<> 144:ef7eb2e8f9f7 109 *
<> 144:ef7eb2e8f9f7 110 * @returns
<> 144:ef7eb2e8f9f7 111 * the byte read
<> 144:ef7eb2e8f9f7 112 */
<> 144:ef7eb2e8f9f7 113 int read(void);
<> 144:ef7eb2e8f9f7 114
<> 144:ef7eb2e8f9f7 115 /** Write to an I2C master.
<> 144:ef7eb2e8f9f7 116 *
<> 144:ef7eb2e8f9f7 117 * @param data pointer to the byte array to be transmitted
<> 144:ef7eb2e8f9f7 118 * @param length the number of bytes to transmite
<> 144:ef7eb2e8f9f7 119 *
<> 144:ef7eb2e8f9f7 120 * @returns
<> 144:ef7eb2e8f9f7 121 * 0 on success,
<> 144:ef7eb2e8f9f7 122 * non-0 otherwise
<> 144:ef7eb2e8f9f7 123 */
<> 144:ef7eb2e8f9f7 124 int write(const char *data, int length);
<> 144:ef7eb2e8f9f7 125
<> 144:ef7eb2e8f9f7 126 /** Write a single byte to an I2C master.
<> 144:ef7eb2e8f9f7 127 *
<> 144:ef7eb2e8f9f7 128 * @data the byte to write
<> 144:ef7eb2e8f9f7 129 *
<> 144:ef7eb2e8f9f7 130 * @returns
<> 144:ef7eb2e8f9f7 131 * '1' if an ACK was received,
<> 144:ef7eb2e8f9f7 132 * '0' otherwise
<> 144:ef7eb2e8f9f7 133 */
<> 144:ef7eb2e8f9f7 134 int write(int data);
<> 144:ef7eb2e8f9f7 135
<> 144:ef7eb2e8f9f7 136 /** Sets the I2C slave address.
<> 144:ef7eb2e8f9f7 137 *
<> 144:ef7eb2e8f9f7 138 * @param address The address to set for the slave (ignoring the least
<> 144:ef7eb2e8f9f7 139 * signifcant bit). If set to 0, the slave will only respond to the
<> 144:ef7eb2e8f9f7 140 * general call address.
<> 144:ef7eb2e8f9f7 141 */
<> 144:ef7eb2e8f9f7 142 void address(int address);
<> 144:ef7eb2e8f9f7 143
<> 144:ef7eb2e8f9f7 144 /** Reset the I2C slave back into the known ready receiving state.
<> 144:ef7eb2e8f9f7 145 */
<> 144:ef7eb2e8f9f7 146 void stop(void);
<> 144:ef7eb2e8f9f7 147
<> 144:ef7eb2e8f9f7 148 protected:
<> 144:ef7eb2e8f9f7 149 i2c_t _i2c;
<> 144:ef7eb2e8f9f7 150 };
<> 144:ef7eb2e8f9f7 151
<> 144:ef7eb2e8f9f7 152 } // namespace mbed
<> 144:ef7eb2e8f9f7 153
<> 144:ef7eb2e8f9f7 154 #endif
<> 144:ef7eb2e8f9f7 155
<> 144:ef7eb2e8f9f7 156 #endif