Lee Kai Xuan / mbed-os

mbed-os

Fork of mbed-os by erkin yucel

drivers/I2CSlave.h@0:f269e3021894, 2016-10-23 (annotated)

Committer:
elessair
Date:
Sun Oct 23 15:10:02 2016 +0000
Revision:
0:f269e3021894
Initial commit

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elessair 0:f269e3021894 1 /* mbed Microcontroller Library
elessair 0:f269e3021894 2 * Copyright (c) 2006-2013 ARM Limited
elessair 0:f269e3021894 3 *
elessair 0:f269e3021894 4 * Licensed under the Apache License, Version 2.0 (the "License");
elessair 0:f269e3021894 5 * you may not use this file except in compliance with the License.
elessair 0:f269e3021894 6 * You may obtain a copy of the License at
elessair 0:f269e3021894 7 *
elessair 0:f269e3021894 8 * http://www.apache.org/licenses/LICENSE-2.0
elessair 0:f269e3021894 9 *
elessair 0:f269e3021894 10 * Unless required by applicable law or agreed to in writing, software
elessair 0:f269e3021894 11 * distributed under the License is distributed on an "AS IS" BASIS,
elessair 0:f269e3021894 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
elessair 0:f269e3021894 13 * See the License for the specific language governing permissions and
elessair 0:f269e3021894 14 * limitations under the License.
elessair 0:f269e3021894 15 */
elessair 0:f269e3021894 16 #ifndef MBED_I2C_SLAVE_H
elessair 0:f269e3021894 17 #define MBED_I2C_SLAVE_H
elessair 0:f269e3021894 18
elessair 0:f269e3021894 19 #include "platform/platform.h"
elessair 0:f269e3021894 20
elessair 0:f269e3021894 21 #if DEVICE_I2CSLAVE
elessair 0:f269e3021894 22
elessair 0:f269e3021894 23 #include "hal/i2c_api.h"
elessair 0:f269e3021894 24
elessair 0:f269e3021894 25 namespace mbed {
elessair 0:f269e3021894 26 /** \addtogroup drivers */
elessair 0:f269e3021894 27 /** @{*/
elessair 0:f269e3021894 28
elessair 0:f269e3021894 29 /** An I2C Slave, used for communicating with an I2C Master device
elessair 0:f269e3021894 30 *
elessair 0:f269e3021894 31 * @Note Synchronization level: Not protected
elessair 0:f269e3021894 32 *
elessair 0:f269e3021894 33 * Example:
elessair 0:f269e3021894 34 * @code
elessair 0:f269e3021894 35 * // Simple I2C responder
elessair 0:f269e3021894 36 * #include <mbed.h>
elessair 0:f269e3021894 37 *
elessair 0:f269e3021894 38 * I2CSlave slave(p9, p10);
elessair 0:f269e3021894 39 *
elessair 0:f269e3021894 40 * int main() {
elessair 0:f269e3021894 41 * char buf[10];
elessair 0:f269e3021894 42 * char msg[] = "Slave!";
elessair 0:f269e3021894 43 *
elessair 0:f269e3021894 44 * slave.address(0xA0);
elessair 0:f269e3021894 45 * while (1) {
elessair 0:f269e3021894 46 * int i = slave.receive();
elessair 0:f269e3021894 47 * switch (i) {
elessair 0:f269e3021894 48 * case I2CSlave::ReadAddressed:
elessair 0:f269e3021894 49 * slave.write(msg, strlen(msg) + 1); // Includes null char
elessair 0:f269e3021894 50 * break;
elessair 0:f269e3021894 51 * case I2CSlave::WriteGeneral:
elessair 0:f269e3021894 52 * slave.read(buf, 10);
elessair 0:f269e3021894 53 * printf("Read G: %s\n", buf);
elessair 0:f269e3021894 54 * break;
elessair 0:f269e3021894 55 * case I2CSlave::WriteAddressed:
elessair 0:f269e3021894 56 * slave.read(buf, 10);
elessair 0:f269e3021894 57 * printf("Read A: %s\n", buf);
elessair 0:f269e3021894 58 * break;
elessair 0:f269e3021894 59 * }
elessair 0:f269e3021894 60 * for(int i = 0; i < 10; i++) buf[i] = 0; // Clear buffer
elessair 0:f269e3021894 61 * }
elessair 0:f269e3021894 62 * }
elessair 0:f269e3021894 63 * @endcode
elessair 0:f269e3021894 64 */
elessair 0:f269e3021894 65 class I2CSlave {
elessair 0:f269e3021894 66
elessair 0:f269e3021894 67 public:
elessair 0:f269e3021894 68 enum RxStatus {
elessair 0:f269e3021894 69 NoData = 0,
elessair 0:f269e3021894 70 ReadAddressed = 1,
elessair 0:f269e3021894 71 WriteGeneral = 2,
elessair 0:f269e3021894 72 WriteAddressed = 3
elessair 0:f269e3021894 73 };
elessair 0:f269e3021894 74
elessair 0:f269e3021894 75 /** Create an I2C Slave interface, connected to the specified pins.
elessair 0:f269e3021894 76 *
elessair 0:f269e3021894 77 * @param sda I2C data line pin
elessair 0:f269e3021894 78 * @param scl I2C clock line pin
elessair 0:f269e3021894 79 */
elessair 0:f269e3021894 80 I2CSlave(PinName sda, PinName scl);
elessair 0:f269e3021894 81
elessair 0:f269e3021894 82 /** Set the frequency of the I2C interface
elessair 0:f269e3021894 83 *
elessair 0:f269e3021894 84 * @param hz The bus frequency in hertz
elessair 0:f269e3021894 85 */
elessair 0:f269e3021894 86 void frequency(int hz);
elessair 0:f269e3021894 87
elessair 0:f269e3021894 88 /** Checks to see if this I2C Slave has been addressed.
elessair 0:f269e3021894 89 *
elessair 0:f269e3021894 90 * @returns
elessair 0:f269e3021894 91 * A status indicating if the device has been addressed, and how
elessair 0:f269e3021894 92 * - NoData - the slave has not been addressed
elessair 0:f269e3021894 93 * - ReadAddressed - the master has requested a read from this slave
elessair 0:f269e3021894 94 * - WriteAddressed - the master is writing to this slave
elessair 0:f269e3021894 95 * - WriteGeneral - the master is writing to all slave
elessair 0:f269e3021894 96 */
elessair 0:f269e3021894 97 int receive(void);
elessair 0:f269e3021894 98
elessair 0:f269e3021894 99 /** Read from an I2C master.
elessair 0:f269e3021894 100 *
elessair 0:f269e3021894 101 * @param data pointer to the byte array to read data in to
elessair 0:f269e3021894 102 * @param length maximum number of bytes to read
elessair 0:f269e3021894 103 *
elessair 0:f269e3021894 104 * @returns
elessair 0:f269e3021894 105 * 0 on success,
elessair 0:f269e3021894 106 * non-0 otherwise
elessair 0:f269e3021894 107 */
elessair 0:f269e3021894 108 int read(char *data, int length);
elessair 0:f269e3021894 109
elessair 0:f269e3021894 110 /** Read a single byte from an I2C master.
elessair 0:f269e3021894 111 *
elessair 0:f269e3021894 112 * @returns
elessair 0:f269e3021894 113 * the byte read
elessair 0:f269e3021894 114 */
elessair 0:f269e3021894 115 int read(void);
elessair 0:f269e3021894 116
elessair 0:f269e3021894 117 /** Write to an I2C master.
elessair 0:f269e3021894 118 *
elessair 0:f269e3021894 119 * @param data pointer to the byte array to be transmitted
elessair 0:f269e3021894 120 * @param length the number of bytes to transmite
elessair 0:f269e3021894 121 *
elessair 0:f269e3021894 122 * @returns
elessair 0:f269e3021894 123 * 0 on success,
elessair 0:f269e3021894 124 * non-0 otherwise
elessair 0:f269e3021894 125 */
elessair 0:f269e3021894 126 int write(const char *data, int length);
elessair 0:f269e3021894 127
elessair 0:f269e3021894 128 /** Write a single byte to an I2C master.
elessair 0:f269e3021894 129 *
elessair 0:f269e3021894 130 * @data the byte to write
elessair 0:f269e3021894 131 *
elessair 0:f269e3021894 132 * @returns
elessair 0:f269e3021894 133 * '1' if an ACK was received,
elessair 0:f269e3021894 134 * '0' otherwise
elessair 0:f269e3021894 135 */
elessair 0:f269e3021894 136 int write(int data);
elessair 0:f269e3021894 137
elessair 0:f269e3021894 138 /** Sets the I2C slave address.
elessair 0:f269e3021894 139 *
elessair 0:f269e3021894 140 * @param address The address to set for the slave (ignoring the least
elessair 0:f269e3021894 141 * signifcant bit). If set to 0, the slave will only respond to the
elessair 0:f269e3021894 142 * general call address.
elessair 0:f269e3021894 143 */
elessair 0:f269e3021894 144 void address(int address);
elessair 0:f269e3021894 145
elessair 0:f269e3021894 146 /** Reset the I2C slave back into the known ready receiving state.
elessair 0:f269e3021894 147 */
elessair 0:f269e3021894 148 void stop(void);
elessair 0:f269e3021894 149
elessair 0:f269e3021894 150 protected:
elessair 0:f269e3021894 151 i2c_t _i2c;
elessair 0:f269e3021894 152 };
elessair 0:f269e3021894 153
elessair 0:f269e3021894 154 } // namespace mbed
elessair 0:f269e3021894 155
elessair 0:f269e3021894 156 #endif
elessair 0:f269e3021894 157
elessair 0:f269e3021894 158 #endif
elessair 0:f269e3021894 159
elessair 0:f269e3021894 160 /** @}*/