1232
drivers/I2CSlave.h@0:06036f8bee2d, 2022-10-24 (annotated)
- Committer:
- ganlikun
- Date:
- Mon Oct 24 15:19:39 2022 +0000
- Revision:
- 0:06036f8bee2d
11
Who changed what in which revision?
User | Revision | Line number | New contents of line |
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ganlikun | 0:06036f8bee2d | 1 | /* mbed Microcontroller Library |
ganlikun | 0:06036f8bee2d | 2 | * Copyright (c) 2006-2013 ARM Limited |
ganlikun | 0:06036f8bee2d | 3 | * |
ganlikun | 0:06036f8bee2d | 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
ganlikun | 0:06036f8bee2d | 5 | * you may not use this file except in compliance with the License. |
ganlikun | 0:06036f8bee2d | 6 | * You may obtain a copy of the License at |
ganlikun | 0:06036f8bee2d | 7 | * |
ganlikun | 0:06036f8bee2d | 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
ganlikun | 0:06036f8bee2d | 9 | * |
ganlikun | 0:06036f8bee2d | 10 | * Unless required by applicable law or agreed to in writing, software |
ganlikun | 0:06036f8bee2d | 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
ganlikun | 0:06036f8bee2d | 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
ganlikun | 0:06036f8bee2d | 13 | * See the License for the specific language governing permissions and |
ganlikun | 0:06036f8bee2d | 14 | * limitations under the License. |
ganlikun | 0:06036f8bee2d | 15 | */ |
ganlikun | 0:06036f8bee2d | 16 | #ifndef MBED_I2C_SLAVE_H |
ganlikun | 0:06036f8bee2d | 17 | #define MBED_I2C_SLAVE_H |
ganlikun | 0:06036f8bee2d | 18 | |
ganlikun | 0:06036f8bee2d | 19 | #include "platform/platform.h" |
ganlikun | 0:06036f8bee2d | 20 | |
ganlikun | 0:06036f8bee2d | 21 | #if defined (DEVICE_I2CSLAVE) || defined(DOXYGEN_ONLY) |
ganlikun | 0:06036f8bee2d | 22 | |
ganlikun | 0:06036f8bee2d | 23 | #include "hal/i2c_api.h" |
ganlikun | 0:06036f8bee2d | 24 | |
ganlikun | 0:06036f8bee2d | 25 | namespace mbed { |
ganlikun | 0:06036f8bee2d | 26 | /** \addtogroup drivers */ |
ganlikun | 0:06036f8bee2d | 27 | |
ganlikun | 0:06036f8bee2d | 28 | /** An I2C Slave, used for communicating with an I2C Master device |
ganlikun | 0:06036f8bee2d | 29 | * |
ganlikun | 0:06036f8bee2d | 30 | * @note Synchronization level: Not protected |
ganlikun | 0:06036f8bee2d | 31 | * |
ganlikun | 0:06036f8bee2d | 32 | * Example: |
ganlikun | 0:06036f8bee2d | 33 | * @code |
ganlikun | 0:06036f8bee2d | 34 | * // Simple I2C responder |
ganlikun | 0:06036f8bee2d | 35 | * #include <mbed.h> |
ganlikun | 0:06036f8bee2d | 36 | * |
ganlikun | 0:06036f8bee2d | 37 | * I2CSlave slave(p9, p10); |
ganlikun | 0:06036f8bee2d | 38 | * |
ganlikun | 0:06036f8bee2d | 39 | * int main() { |
ganlikun | 0:06036f8bee2d | 40 | * char buf[10]; |
ganlikun | 0:06036f8bee2d | 41 | * char msg[] = "Slave!"; |
ganlikun | 0:06036f8bee2d | 42 | * |
ganlikun | 0:06036f8bee2d | 43 | * slave.address(0xA0); |
ganlikun | 0:06036f8bee2d | 44 | * while (1) { |
ganlikun | 0:06036f8bee2d | 45 | * int i = slave.receive(); |
ganlikun | 0:06036f8bee2d | 46 | * switch (i) { |
ganlikun | 0:06036f8bee2d | 47 | * case I2CSlave::ReadAddressed: |
ganlikun | 0:06036f8bee2d | 48 | * slave.write(msg, strlen(msg) + 1); // Includes null char |
ganlikun | 0:06036f8bee2d | 49 | * break; |
ganlikun | 0:06036f8bee2d | 50 | * case I2CSlave::WriteGeneral: |
ganlikun | 0:06036f8bee2d | 51 | * slave.read(buf, 10); |
ganlikun | 0:06036f8bee2d | 52 | * printf("Read G: %s\n", buf); |
ganlikun | 0:06036f8bee2d | 53 | * break; |
ganlikun | 0:06036f8bee2d | 54 | * case I2CSlave::WriteAddressed: |
ganlikun | 0:06036f8bee2d | 55 | * slave.read(buf, 10); |
ganlikun | 0:06036f8bee2d | 56 | * printf("Read A: %s\n", buf); |
ganlikun | 0:06036f8bee2d | 57 | * break; |
ganlikun | 0:06036f8bee2d | 58 | * } |
ganlikun | 0:06036f8bee2d | 59 | * for(int i = 0; i < 10; i++) buf[i] = 0; // Clear buffer |
ganlikun | 0:06036f8bee2d | 60 | * } |
ganlikun | 0:06036f8bee2d | 61 | * } |
ganlikun | 0:06036f8bee2d | 62 | * @endcode |
ganlikun | 0:06036f8bee2d | 63 | * @ingroup drivers |
ganlikun | 0:06036f8bee2d | 64 | */ |
ganlikun | 0:06036f8bee2d | 65 | class I2CSlave { |
ganlikun | 0:06036f8bee2d | 66 | |
ganlikun | 0:06036f8bee2d | 67 | public: |
ganlikun | 0:06036f8bee2d | 68 | enum RxStatus { |
ganlikun | 0:06036f8bee2d | 69 | NoData = 0, |
ganlikun | 0:06036f8bee2d | 70 | ReadAddressed = 1, |
ganlikun | 0:06036f8bee2d | 71 | WriteGeneral = 2, |
ganlikun | 0:06036f8bee2d | 72 | WriteAddressed = 3 |
ganlikun | 0:06036f8bee2d | 73 | }; |
ganlikun | 0:06036f8bee2d | 74 | |
ganlikun | 0:06036f8bee2d | 75 | /** Create an I2C Slave interface, connected to the specified pins. |
ganlikun | 0:06036f8bee2d | 76 | * |
ganlikun | 0:06036f8bee2d | 77 | * @param sda I2C data line pin |
ganlikun | 0:06036f8bee2d | 78 | * @param scl I2C clock line pin |
ganlikun | 0:06036f8bee2d | 79 | */ |
ganlikun | 0:06036f8bee2d | 80 | I2CSlave(PinName sda, PinName scl); |
ganlikun | 0:06036f8bee2d | 81 | |
ganlikun | 0:06036f8bee2d | 82 | /** Set the frequency of the I2C interface |
ganlikun | 0:06036f8bee2d | 83 | * |
ganlikun | 0:06036f8bee2d | 84 | * @param hz The bus frequency in hertz |
ganlikun | 0:06036f8bee2d | 85 | */ |
ganlikun | 0:06036f8bee2d | 86 | void frequency(int hz); |
ganlikun | 0:06036f8bee2d | 87 | |
ganlikun | 0:06036f8bee2d | 88 | /** Checks to see if this I2C Slave has been addressed. |
ganlikun | 0:06036f8bee2d | 89 | * |
ganlikun | 0:06036f8bee2d | 90 | * @returns |
ganlikun | 0:06036f8bee2d | 91 | * A status indicating if the device has been addressed, and how |
ganlikun | 0:06036f8bee2d | 92 | * - NoData - the slave has not been addressed |
ganlikun | 0:06036f8bee2d | 93 | * - ReadAddressed - the master has requested a read from this slave |
ganlikun | 0:06036f8bee2d | 94 | * - WriteAddressed - the master is writing to this slave |
ganlikun | 0:06036f8bee2d | 95 | * - WriteGeneral - the master is writing to all slave |
ganlikun | 0:06036f8bee2d | 96 | */ |
ganlikun | 0:06036f8bee2d | 97 | int receive(void); |
ganlikun | 0:06036f8bee2d | 98 | |
ganlikun | 0:06036f8bee2d | 99 | /** Read from an I2C master. |
ganlikun | 0:06036f8bee2d | 100 | * |
ganlikun | 0:06036f8bee2d | 101 | * @param data pointer to the byte array to read data in to |
ganlikun | 0:06036f8bee2d | 102 | * @param length maximum number of bytes to read |
ganlikun | 0:06036f8bee2d | 103 | * |
ganlikun | 0:06036f8bee2d | 104 | * @returns |
ganlikun | 0:06036f8bee2d | 105 | * 0 on success, |
ganlikun | 0:06036f8bee2d | 106 | * non-0 otherwise |
ganlikun | 0:06036f8bee2d | 107 | */ |
ganlikun | 0:06036f8bee2d | 108 | int read(char *data, int length); |
ganlikun | 0:06036f8bee2d | 109 | |
ganlikun | 0:06036f8bee2d | 110 | /** Read a single byte from an I2C master. |
ganlikun | 0:06036f8bee2d | 111 | * |
ganlikun | 0:06036f8bee2d | 112 | * @returns |
ganlikun | 0:06036f8bee2d | 113 | * the byte read |
ganlikun | 0:06036f8bee2d | 114 | */ |
ganlikun | 0:06036f8bee2d | 115 | int read(void); |
ganlikun | 0:06036f8bee2d | 116 | |
ganlikun | 0:06036f8bee2d | 117 | /** Write to an I2C master. |
ganlikun | 0:06036f8bee2d | 118 | * |
ganlikun | 0:06036f8bee2d | 119 | * @param data pointer to the byte array to be transmitted |
ganlikun | 0:06036f8bee2d | 120 | * @param length the number of bytes to transmite |
ganlikun | 0:06036f8bee2d | 121 | * |
ganlikun | 0:06036f8bee2d | 122 | * @returns |
ganlikun | 0:06036f8bee2d | 123 | * 0 on success, |
ganlikun | 0:06036f8bee2d | 124 | * non-0 otherwise |
ganlikun | 0:06036f8bee2d | 125 | */ |
ganlikun | 0:06036f8bee2d | 126 | int write(const char *data, int length); |
ganlikun | 0:06036f8bee2d | 127 | |
ganlikun | 0:06036f8bee2d | 128 | /** Write a single byte to an I2C master. |
ganlikun | 0:06036f8bee2d | 129 | * |
ganlikun | 0:06036f8bee2d | 130 | * @param data the byte to write |
ganlikun | 0:06036f8bee2d | 131 | * |
ganlikun | 0:06036f8bee2d | 132 | * @returns |
ganlikun | 0:06036f8bee2d | 133 | * '1' if an ACK was received, |
ganlikun | 0:06036f8bee2d | 134 | * '0' otherwise |
ganlikun | 0:06036f8bee2d | 135 | */ |
ganlikun | 0:06036f8bee2d | 136 | int write(int data); |
ganlikun | 0:06036f8bee2d | 137 | |
ganlikun | 0:06036f8bee2d | 138 | /** Sets the I2C slave address. |
ganlikun | 0:06036f8bee2d | 139 | * |
ganlikun | 0:06036f8bee2d | 140 | * @param address The address to set for the slave (ignoring the least |
ganlikun | 0:06036f8bee2d | 141 | * signifcant bit). If set to 0, the slave will only respond to the |
ganlikun | 0:06036f8bee2d | 142 | * general call address. |
ganlikun | 0:06036f8bee2d | 143 | */ |
ganlikun | 0:06036f8bee2d | 144 | void address(int address); |
ganlikun | 0:06036f8bee2d | 145 | |
ganlikun | 0:06036f8bee2d | 146 | /** Reset the I2C slave back into the known ready receiving state. |
ganlikun | 0:06036f8bee2d | 147 | */ |
ganlikun | 0:06036f8bee2d | 148 | void stop(void); |
ganlikun | 0:06036f8bee2d | 149 | |
ganlikun | 0:06036f8bee2d | 150 | protected: |
ganlikun | 0:06036f8bee2d | 151 | i2c_t _i2c; |
ganlikun | 0:06036f8bee2d | 152 | }; |
ganlikun | 0:06036f8bee2d | 153 | |
ganlikun | 0:06036f8bee2d | 154 | } // namespace mbed |
ganlikun | 0:06036f8bee2d | 155 | |
ganlikun | 0:06036f8bee2d | 156 | #endif |
ganlikun | 0:06036f8bee2d | 157 | |
ganlikun | 0:06036f8bee2d | 158 | #endif |