Neil Johnson / microbit-ARMBand

Official Sheffield ARMBand micro:bit program

microbit/microbit-dal/mbed-dev-bin/I2CSlave.h@0:b9164b348919, 2016-10-17 (annotated)

Committer:
MrBedfordVan
Date:
Mon Oct 17 12:41:20 2016 +0000
Revision:
0:b9164b348919
Official Sheffield ARMBand Micro:bit program

Who changed what in which revision?

UserRevisionLine numberNew contents of line
MrBedfordVan 0:b9164b348919 1 /* mbed Microcontroller Library
MrBedfordVan 0:b9164b348919 2 * Copyright (c) 2006-2013 ARM Limited
MrBedfordVan 0:b9164b348919 3 *
MrBedfordVan 0:b9164b348919 4 * Licensed under the Apache License, Version 2.0 (the "License");
MrBedfordVan 0:b9164b348919 5 * you may not use this file except in compliance with the License.
MrBedfordVan 0:b9164b348919 6 * You may obtain a copy of the License at
MrBedfordVan 0:b9164b348919 7 *
MrBedfordVan 0:b9164b348919 8 * http://www.apache.org/licenses/LICENSE-2.0
MrBedfordVan 0:b9164b348919 9 *
MrBedfordVan 0:b9164b348919 10 * Unless required by applicable law or agreed to in writing, software
MrBedfordVan 0:b9164b348919 11 * distributed under the License is distributed on an "AS IS" BASIS,
MrBedfordVan 0:b9164b348919 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
MrBedfordVan 0:b9164b348919 13 * See the License for the specific language governing permissions and
MrBedfordVan 0:b9164b348919 14 * limitations under the License.
MrBedfordVan 0:b9164b348919 15 */
MrBedfordVan 0:b9164b348919 16 #ifndef MBED_I2C_SLAVE_H
MrBedfordVan 0:b9164b348919 17 #define MBED_I2C_SLAVE_H
MrBedfordVan 0:b9164b348919 18
MrBedfordVan 0:b9164b348919 19 #include "platform.h"
MrBedfordVan 0:b9164b348919 20
MrBedfordVan 0:b9164b348919 21 #if DEVICE_I2CSLAVE
MrBedfordVan 0:b9164b348919 22
MrBedfordVan 0:b9164b348919 23 #include "i2c_api.h"
MrBedfordVan 0:b9164b348919 24
MrBedfordVan 0:b9164b348919 25 namespace mbed {
MrBedfordVan 0:b9164b348919 26
MrBedfordVan 0:b9164b348919 27 /** An I2C Slave, used for communicating with an I2C Master device
MrBedfordVan 0:b9164b348919 28 *
MrBedfordVan 0:b9164b348919 29 * Example:
MrBedfordVan 0:b9164b348919 30 * @code
MrBedfordVan 0:b9164b348919 31 * // Simple I2C responder
MrBedfordVan 0:b9164b348919 32 * #include <mbed.h>
MrBedfordVan 0:b9164b348919 33 *
MrBedfordVan 0:b9164b348919 34 * I2CSlave slave(p9, p10);
MrBedfordVan 0:b9164b348919 35 *
MrBedfordVan 0:b9164b348919 36 * int main() {
MrBedfordVan 0:b9164b348919 37 * char buf[10];
MrBedfordVan 0:b9164b348919 38 * char msg[] = "Slave!";
MrBedfordVan 0:b9164b348919 39 *
MrBedfordVan 0:b9164b348919 40 * slave.address(0xA0);
MrBedfordVan 0:b9164b348919 41 * while (1) {
MrBedfordVan 0:b9164b348919 42 * int i = slave.receive();
MrBedfordVan 0:b9164b348919 43 * switch (i) {
MrBedfordVan 0:b9164b348919 44 * case I2CSlave::ReadAddressed:
MrBedfordVan 0:b9164b348919 45 * slave.write(msg, strlen(msg) + 1); // Includes null char
MrBedfordVan 0:b9164b348919 46 * break;
MrBedfordVan 0:b9164b348919 47 * case I2CSlave::WriteGeneral:
MrBedfordVan 0:b9164b348919 48 * slave.read(buf, 10);
MrBedfordVan 0:b9164b348919 49 * printf("Read G: %s\n", buf);
MrBedfordVan 0:b9164b348919 50 * break;
MrBedfordVan 0:b9164b348919 51 * case I2CSlave::WriteAddressed:
MrBedfordVan 0:b9164b348919 52 * slave.read(buf, 10);
MrBedfordVan 0:b9164b348919 53 * printf("Read A: %s\n", buf);
MrBedfordVan 0:b9164b348919 54 * break;
MrBedfordVan 0:b9164b348919 55 * }
MrBedfordVan 0:b9164b348919 56 * for(int i = 0; i < 10; i++) buf[i] = 0; // Clear buffer
MrBedfordVan 0:b9164b348919 57 * }
MrBedfordVan 0:b9164b348919 58 * }
MrBedfordVan 0:b9164b348919 59 * @endcode
MrBedfordVan 0:b9164b348919 60 */
MrBedfordVan 0:b9164b348919 61 class I2CSlave {
MrBedfordVan 0:b9164b348919 62
MrBedfordVan 0:b9164b348919 63 public:
MrBedfordVan 0:b9164b348919 64 enum RxStatus {
MrBedfordVan 0:b9164b348919 65 NoData = 0,
MrBedfordVan 0:b9164b348919 66 ReadAddressed = 1,
MrBedfordVan 0:b9164b348919 67 WriteGeneral = 2,
MrBedfordVan 0:b9164b348919 68 WriteAddressed = 3
MrBedfordVan 0:b9164b348919 69 };
MrBedfordVan 0:b9164b348919 70
MrBedfordVan 0:b9164b348919 71 /** Create an I2C Slave interface, connected to the specified pins.
MrBedfordVan 0:b9164b348919 72 *
MrBedfordVan 0:b9164b348919 73 * @param sda I2C data line pin
MrBedfordVan 0:b9164b348919 74 * @param scl I2C clock line pin
MrBedfordVan 0:b9164b348919 75 */
MrBedfordVan 0:b9164b348919 76 I2CSlave(PinName sda, PinName scl);
MrBedfordVan 0:b9164b348919 77
MrBedfordVan 0:b9164b348919 78 /** Set the frequency of the I2C interface
MrBedfordVan 0:b9164b348919 79 *
MrBedfordVan 0:b9164b348919 80 * @param hz The bus frequency in hertz
MrBedfordVan 0:b9164b348919 81 */
MrBedfordVan 0:b9164b348919 82 void frequency(int hz);
MrBedfordVan 0:b9164b348919 83
MrBedfordVan 0:b9164b348919 84 /** Checks to see if this I2C Slave has been addressed.
MrBedfordVan 0:b9164b348919 85 *
MrBedfordVan 0:b9164b348919 86 * @returns
MrBedfordVan 0:b9164b348919 87 * A status indicating if the device has been addressed, and how
MrBedfordVan 0:b9164b348919 88 * - NoData - the slave has not been addressed
MrBedfordVan 0:b9164b348919 89 * - ReadAddressed - the master has requested a read from this slave
MrBedfordVan 0:b9164b348919 90 * - WriteAddressed - the master is writing to this slave
MrBedfordVan 0:b9164b348919 91 * - WriteGeneral - the master is writing to all slave
MrBedfordVan 0:b9164b348919 92 */
MrBedfordVan 0:b9164b348919 93 int receive(void);
MrBedfordVan 0:b9164b348919 94
MrBedfordVan 0:b9164b348919 95 /** Read from an I2C master.
MrBedfordVan 0:b9164b348919 96 *
MrBedfordVan 0:b9164b348919 97 * @param data pointer to the byte array to read data in to
MrBedfordVan 0:b9164b348919 98 * @param length maximum number of bytes to read
MrBedfordVan 0:b9164b348919 99 *
MrBedfordVan 0:b9164b348919 100 * @returns
MrBedfordVan 0:b9164b348919 101 * 0 on success,
MrBedfordVan 0:b9164b348919 102 * non-0 otherwise
MrBedfordVan 0:b9164b348919 103 */
MrBedfordVan 0:b9164b348919 104 int read(char *data, int length);
MrBedfordVan 0:b9164b348919 105
MrBedfordVan 0:b9164b348919 106 /** Read a single byte from an I2C master.
MrBedfordVan 0:b9164b348919 107 *
MrBedfordVan 0:b9164b348919 108 * @returns
MrBedfordVan 0:b9164b348919 109 * the byte read
MrBedfordVan 0:b9164b348919 110 */
MrBedfordVan 0:b9164b348919 111 int read(void);
MrBedfordVan 0:b9164b348919 112
MrBedfordVan 0:b9164b348919 113 /** Write to an I2C master.
MrBedfordVan 0:b9164b348919 114 *
MrBedfordVan 0:b9164b348919 115 * @param data pointer to the byte array to be transmitted
MrBedfordVan 0:b9164b348919 116 * @param length the number of bytes to transmite
MrBedfordVan 0:b9164b348919 117 *
MrBedfordVan 0:b9164b348919 118 * @returns
MrBedfordVan 0:b9164b348919 119 * 0 on success,
MrBedfordVan 0:b9164b348919 120 * non-0 otherwise
MrBedfordVan 0:b9164b348919 121 */
MrBedfordVan 0:b9164b348919 122 int write(const char *data, int length);
MrBedfordVan 0:b9164b348919 123
MrBedfordVan 0:b9164b348919 124 /** Write a single byte to an I2C master.
MrBedfordVan 0:b9164b348919 125 *
MrBedfordVan 0:b9164b348919 126 * @data the byte to write
MrBedfordVan 0:b9164b348919 127 *
MrBedfordVan 0:b9164b348919 128 * @returns
MrBedfordVan 0:b9164b348919 129 * '1' if an ACK was received,
MrBedfordVan 0:b9164b348919 130 * '0' otherwise
MrBedfordVan 0:b9164b348919 131 */
MrBedfordVan 0:b9164b348919 132 int write(int data);
MrBedfordVan 0:b9164b348919 133
MrBedfordVan 0:b9164b348919 134 /** Sets the I2C slave address.
MrBedfordVan 0:b9164b348919 135 *
MrBedfordVan 0:b9164b348919 136 * @param address The address to set for the slave (ignoring the least
MrBedfordVan 0:b9164b348919 137 * signifcant bit). If set to 0, the slave will only respond to the
MrBedfordVan 0:b9164b348919 138 * general call address.
MrBedfordVan 0:b9164b348919 139 */
MrBedfordVan 0:b9164b348919 140 void address(int address);
MrBedfordVan 0:b9164b348919 141
MrBedfordVan 0:b9164b348919 142 /** Reset the I2C slave back into the known ready receiving state.
MrBedfordVan 0:b9164b348919 143 */
MrBedfordVan 0:b9164b348919 144 void stop(void);
MrBedfordVan 0:b9164b348919 145
MrBedfordVan 0:b9164b348919 146 protected:
MrBedfordVan 0:b9164b348919 147 i2c_t _i2c;
MrBedfordVan 0:b9164b348919 148 };
MrBedfordVan 0:b9164b348919 149
MrBedfordVan 0:b9164b348919 150 } // namespace mbed
MrBedfordVan 0:b9164b348919 151
MrBedfordVan 0:b9164b348919 152 #endif
MrBedfordVan 0:b9164b348919 153
MrBedfordVan 0:b9164b348919 154 #endif