Martin Cottrell / mbed-dev-bin

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Dependents:   microbit-dal

Fork of mbed-dev-bin by Lancaster University

I2CSlave.h@4:5d949669b10e, 2017-01-13 (annotated)

Committer:
Asimov
Date:
Fri Jan 13 20:58:56 2017 +0000
Revision:
4:5d949669b10e
Parent:
0:e1a608bb55e8 
No real changes?  DemoMicroBit_PCA9685

Who changed what in which revision?

UserRevisionLine numberNew contents of line
jamesadevine 0:e1a608bb55e8 1 /* mbed Microcontroller Library
jamesadevine 0:e1a608bb55e8 2 * Copyright (c) 2006-2013 ARM Limited
jamesadevine 0:e1a608bb55e8 3 *
jamesadevine 0:e1a608bb55e8 4 * Licensed under the Apache License, Version 2.0 (the "License");
jamesadevine 0:e1a608bb55e8 5 * you may not use this file except in compliance with the License.
jamesadevine 0:e1a608bb55e8 6 * You may obtain a copy of the License at
jamesadevine 0:e1a608bb55e8 7 *
jamesadevine 0:e1a608bb55e8 8 * http://www.apache.org/licenses/LICENSE-2.0
jamesadevine 0:e1a608bb55e8 9 *
jamesadevine 0:e1a608bb55e8 10 * Unless required by applicable law or agreed to in writing, software
jamesadevine 0:e1a608bb55e8 11 * distributed under the License is distributed on an "AS IS" BASIS,
jamesadevine 0:e1a608bb55e8 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
jamesadevine 0:e1a608bb55e8 13 * See the License for the specific language governing permissions and
jamesadevine 0:e1a608bb55e8 14 * limitations under the License.
jamesadevine 0:e1a608bb55e8 15 */
jamesadevine 0:e1a608bb55e8 16 #ifndef MBED_I2C_SLAVE_H
jamesadevine 0:e1a608bb55e8 17 #define MBED_I2C_SLAVE_H
jamesadevine 0:e1a608bb55e8 18
jamesadevine 0:e1a608bb55e8 19 #include "platform.h"
jamesadevine 0:e1a608bb55e8 20
jamesadevine 0:e1a608bb55e8 21 #if DEVICE_I2CSLAVE
jamesadevine 0:e1a608bb55e8 22
jamesadevine 0:e1a608bb55e8 23 #include "i2c_api.h"
jamesadevine 0:e1a608bb55e8 24
jamesadevine 0:e1a608bb55e8 25 namespace mbed {
jamesadevine 0:e1a608bb55e8 26
jamesadevine 0:e1a608bb55e8 27 /** An I2C Slave, used for communicating with an I2C Master device
jamesadevine 0:e1a608bb55e8 28 *
jamesadevine 0:e1a608bb55e8 29 * Example:
jamesadevine 0:e1a608bb55e8 30 * @code
jamesadevine 0:e1a608bb55e8 31 * // Simple I2C responder
jamesadevine 0:e1a608bb55e8 32 * #include <mbed.h>
jamesadevine 0:e1a608bb55e8 33 *
jamesadevine 0:e1a608bb55e8 34 * I2CSlave slave(p9, p10);
jamesadevine 0:e1a608bb55e8 35 *
jamesadevine 0:e1a608bb55e8 36 * int main() {
jamesadevine 0:e1a608bb55e8 37 * char buf[10];
jamesadevine 0:e1a608bb55e8 38 * char msg[] = "Slave!";
jamesadevine 0:e1a608bb55e8 39 *
jamesadevine 0:e1a608bb55e8 40 * slave.address(0xA0);
jamesadevine 0:e1a608bb55e8 41 * while (1) {
jamesadevine 0:e1a608bb55e8 42 * int i = slave.receive();
jamesadevine 0:e1a608bb55e8 43 * switch (i) {
jamesadevine 0:e1a608bb55e8 44 * case I2CSlave::ReadAddressed:
jamesadevine 0:e1a608bb55e8 45 * slave.write(msg, strlen(msg) + 1); // Includes null char
jamesadevine 0:e1a608bb55e8 46 * break;
jamesadevine 0:e1a608bb55e8 47 * case I2CSlave::WriteGeneral:
jamesadevine 0:e1a608bb55e8 48 * slave.read(buf, 10);
jamesadevine 0:e1a608bb55e8 49 * printf("Read G: %s\n", buf);
jamesadevine 0:e1a608bb55e8 50 * break;
jamesadevine 0:e1a608bb55e8 51 * case I2CSlave::WriteAddressed:
jamesadevine 0:e1a608bb55e8 52 * slave.read(buf, 10);
jamesadevine 0:e1a608bb55e8 53 * printf("Read A: %s\n", buf);
jamesadevine 0:e1a608bb55e8 54 * break;
jamesadevine 0:e1a608bb55e8 55 * }
jamesadevine 0:e1a608bb55e8 56 * for(int i = 0; i < 10; i++) buf[i] = 0; // Clear buffer
jamesadevine 0:e1a608bb55e8 57 * }
jamesadevine 0:e1a608bb55e8 58 * }
jamesadevine 0:e1a608bb55e8 59 * @endcode
jamesadevine 0:e1a608bb55e8 60 */
jamesadevine 0:e1a608bb55e8 61 class I2CSlave {
jamesadevine 0:e1a608bb55e8 62
jamesadevine 0:e1a608bb55e8 63 public:
jamesadevine 0:e1a608bb55e8 64 enum RxStatus {
jamesadevine 0:e1a608bb55e8 65 NoData = 0,
jamesadevine 0:e1a608bb55e8 66 ReadAddressed = 1,
jamesadevine 0:e1a608bb55e8 67 WriteGeneral = 2,
jamesadevine 0:e1a608bb55e8 68 WriteAddressed = 3
jamesadevine 0:e1a608bb55e8 69 };
jamesadevine 0:e1a608bb55e8 70
jamesadevine 0:e1a608bb55e8 71 /** Create an I2C Slave interface, connected to the specified pins.
jamesadevine 0:e1a608bb55e8 72 *
jamesadevine 0:e1a608bb55e8 73 * @param sda I2C data line pin
jamesadevine 0:e1a608bb55e8 74 * @param scl I2C clock line pin
jamesadevine 0:e1a608bb55e8 75 */
jamesadevine 0:e1a608bb55e8 76 I2CSlave(PinName sda, PinName scl);
jamesadevine 0:e1a608bb55e8 77
jamesadevine 0:e1a608bb55e8 78 /** Set the frequency of the I2C interface
jamesadevine 0:e1a608bb55e8 79 *
jamesadevine 0:e1a608bb55e8 80 * @param hz The bus frequency in hertz
jamesadevine 0:e1a608bb55e8 81 */
jamesadevine 0:e1a608bb55e8 82 void frequency(int hz);
jamesadevine 0:e1a608bb55e8 83
jamesadevine 0:e1a608bb55e8 84 /** Checks to see if this I2C Slave has been addressed.
jamesadevine 0:e1a608bb55e8 85 *
jamesadevine 0:e1a608bb55e8 86 * @returns
jamesadevine 0:e1a608bb55e8 87 * A status indicating if the device has been addressed, and how
jamesadevine 0:e1a608bb55e8 88 * - NoData - the slave has not been addressed
jamesadevine 0:e1a608bb55e8 89 * - ReadAddressed - the master has requested a read from this slave
jamesadevine 0:e1a608bb55e8 90 * - WriteAddressed - the master is writing to this slave
jamesadevine 0:e1a608bb55e8 91 * - WriteGeneral - the master is writing to all slave
jamesadevine 0:e1a608bb55e8 92 */
jamesadevine 0:e1a608bb55e8 93 int receive(void);
jamesadevine 0:e1a608bb55e8 94
jamesadevine 0:e1a608bb55e8 95 /** Read from an I2C master.
jamesadevine 0:e1a608bb55e8 96 *
jamesadevine 0:e1a608bb55e8 97 * @param data pointer to the byte array to read data in to
jamesadevine 0:e1a608bb55e8 98 * @param length maximum number of bytes to read
jamesadevine 0:e1a608bb55e8 99 *
jamesadevine 0:e1a608bb55e8 100 * @returns
jamesadevine 0:e1a608bb55e8 101 * 0 on success,
jamesadevine 0:e1a608bb55e8 102 * non-0 otherwise
jamesadevine 0:e1a608bb55e8 103 */
jamesadevine 0:e1a608bb55e8 104 int read(char *data, int length);
jamesadevine 0:e1a608bb55e8 105
jamesadevine 0:e1a608bb55e8 106 /** Read a single byte from an I2C master.
jamesadevine 0:e1a608bb55e8 107 *
jamesadevine 0:e1a608bb55e8 108 * @returns
jamesadevine 0:e1a608bb55e8 109 * the byte read
jamesadevine 0:e1a608bb55e8 110 */
jamesadevine 0:e1a608bb55e8 111 int read(void);
jamesadevine 0:e1a608bb55e8 112
jamesadevine 0:e1a608bb55e8 113 /** Write to an I2C master.
jamesadevine 0:e1a608bb55e8 114 *
jamesadevine 0:e1a608bb55e8 115 * @param data pointer to the byte array to be transmitted
jamesadevine 0:e1a608bb55e8 116 * @param length the number of bytes to transmite
jamesadevine 0:e1a608bb55e8 117 *
jamesadevine 0:e1a608bb55e8 118 * @returns
jamesadevine 0:e1a608bb55e8 119 * 0 on success,
jamesadevine 0:e1a608bb55e8 120 * non-0 otherwise
jamesadevine 0:e1a608bb55e8 121 */
jamesadevine 0:e1a608bb55e8 122 int write(const char *data, int length);
jamesadevine 0:e1a608bb55e8 123
jamesadevine 0:e1a608bb55e8 124 /** Write a single byte to an I2C master.
jamesadevine 0:e1a608bb55e8 125 *
jamesadevine 0:e1a608bb55e8 126 * @data the byte to write
jamesadevine 0:e1a608bb55e8 127 *
jamesadevine 0:e1a608bb55e8 128 * @returns
jamesadevine 0:e1a608bb55e8 129 * '1' if an ACK was received,
jamesadevine 0:e1a608bb55e8 130 * '0' otherwise
jamesadevine 0:e1a608bb55e8 131 */
jamesadevine 0:e1a608bb55e8 132 int write(int data);
jamesadevine 0:e1a608bb55e8 133
jamesadevine 0:e1a608bb55e8 134 /** Sets the I2C slave address.
jamesadevine 0:e1a608bb55e8 135 *
jamesadevine 0:e1a608bb55e8 136 * @param address The address to set for the slave (ignoring the least
jamesadevine 0:e1a608bb55e8 137 * signifcant bit). If set to 0, the slave will only respond to the
jamesadevine 0:e1a608bb55e8 138 * general call address.
jamesadevine 0:e1a608bb55e8 139 */
jamesadevine 0:e1a608bb55e8 140 void address(int address);
jamesadevine 0:e1a608bb55e8 141
jamesadevine 0:e1a608bb55e8 142 /** Reset the I2C slave back into the known ready receiving state.
jamesadevine 0:e1a608bb55e8 143 */
jamesadevine 0:e1a608bb55e8 144 void stop(void);
jamesadevine 0:e1a608bb55e8 145
jamesadevine 0:e1a608bb55e8 146 protected:
jamesadevine 0:e1a608bb55e8 147 i2c_t _i2c;
jamesadevine 0:e1a608bb55e8 148 };
jamesadevine 0:e1a608bb55e8 149
jamesadevine 0:e1a608bb55e8 150 } // namespace mbed
jamesadevine 0:e1a608bb55e8 151
jamesadevine 0:e1a608bb55e8 152 #endif
jamesadevine 0:e1a608bb55e8 153
jamesadevine 0:e1a608bb55e8 154 #endif