mbed
Dependents: DHTSensor_Test K64F_eCompass_OneNET_JW
I2C.h@0:2cc6bb4d7fea, 2015-02-25 (annotated)
- Committer:
- mbotkinl
- Date:
- Wed Feb 25 20:22:22 2015 +0000
- Revision:
- 0:2cc6bb4d7fea
Working code to read Temperature and Humidity readings
Who changed what in which revision?
User | Revision | Line number | New contents of line |
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mbotkinl | 0:2cc6bb4d7fea | 1 | /* mbed Microcontroller Library |
mbotkinl | 0:2cc6bb4d7fea | 2 | * Copyright (c) 2006-2013 ARM Limited |
mbotkinl | 0:2cc6bb4d7fea | 3 | * |
mbotkinl | 0:2cc6bb4d7fea | 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
mbotkinl | 0:2cc6bb4d7fea | 5 | * you may not use this file except in compliance with the License. |
mbotkinl | 0:2cc6bb4d7fea | 6 | * You may obtain a copy of the License at |
mbotkinl | 0:2cc6bb4d7fea | 7 | * |
mbotkinl | 0:2cc6bb4d7fea | 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
mbotkinl | 0:2cc6bb4d7fea | 9 | * |
mbotkinl | 0:2cc6bb4d7fea | 10 | * Unless required by applicable law or agreed to in writing, software |
mbotkinl | 0:2cc6bb4d7fea | 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
mbotkinl | 0:2cc6bb4d7fea | 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
mbotkinl | 0:2cc6bb4d7fea | 13 | * See the License for the specific language governing permissions and |
mbotkinl | 0:2cc6bb4d7fea | 14 | * limitations under the License. |
mbotkinl | 0:2cc6bb4d7fea | 15 | */ |
mbotkinl | 0:2cc6bb4d7fea | 16 | #ifndef MBED_I2C_H |
mbotkinl | 0:2cc6bb4d7fea | 17 | #define MBED_I2C_H |
mbotkinl | 0:2cc6bb4d7fea | 18 | |
mbotkinl | 0:2cc6bb4d7fea | 19 | #include "platform.h" |
mbotkinl | 0:2cc6bb4d7fea | 20 | |
mbotkinl | 0:2cc6bb4d7fea | 21 | #if DEVICE_I2C |
mbotkinl | 0:2cc6bb4d7fea | 22 | |
mbotkinl | 0:2cc6bb4d7fea | 23 | #include "i2c_api.h" |
mbotkinl | 0:2cc6bb4d7fea | 24 | |
mbotkinl | 0:2cc6bb4d7fea | 25 | namespace mbed { |
mbotkinl | 0:2cc6bb4d7fea | 26 | |
mbotkinl | 0:2cc6bb4d7fea | 27 | /** An I2C Master, used for communicating with I2C slave devices |
mbotkinl | 0:2cc6bb4d7fea | 28 | * |
mbotkinl | 0:2cc6bb4d7fea | 29 | * Example: |
mbotkinl | 0:2cc6bb4d7fea | 30 | * @code |
mbotkinl | 0:2cc6bb4d7fea | 31 | * // Read from I2C slave at address 0x62 |
mbotkinl | 0:2cc6bb4d7fea | 32 | * |
mbotkinl | 0:2cc6bb4d7fea | 33 | * #include "mbed.h" |
mbotkinl | 0:2cc6bb4d7fea | 34 | * |
mbotkinl | 0:2cc6bb4d7fea | 35 | * I2C i2c(p28, p27); |
mbotkinl | 0:2cc6bb4d7fea | 36 | * |
mbotkinl | 0:2cc6bb4d7fea | 37 | * int main() { |
mbotkinl | 0:2cc6bb4d7fea | 38 | * int address = 0x62; |
mbotkinl | 0:2cc6bb4d7fea | 39 | * char data[2]; |
mbotkinl | 0:2cc6bb4d7fea | 40 | * i2c.read(address, data, 2); |
mbotkinl | 0:2cc6bb4d7fea | 41 | * } |
mbotkinl | 0:2cc6bb4d7fea | 42 | * @endcode |
mbotkinl | 0:2cc6bb4d7fea | 43 | */ |
mbotkinl | 0:2cc6bb4d7fea | 44 | class I2C { |
mbotkinl | 0:2cc6bb4d7fea | 45 | |
mbotkinl | 0:2cc6bb4d7fea | 46 | public: |
mbotkinl | 0:2cc6bb4d7fea | 47 | enum RxStatus { |
mbotkinl | 0:2cc6bb4d7fea | 48 | NoData, |
mbotkinl | 0:2cc6bb4d7fea | 49 | MasterGeneralCall, |
mbotkinl | 0:2cc6bb4d7fea | 50 | MasterWrite, |
mbotkinl | 0:2cc6bb4d7fea | 51 | MasterRead |
mbotkinl | 0:2cc6bb4d7fea | 52 | }; |
mbotkinl | 0:2cc6bb4d7fea | 53 | |
mbotkinl | 0:2cc6bb4d7fea | 54 | enum Acknowledge { |
mbotkinl | 0:2cc6bb4d7fea | 55 | NoACK = 0, |
mbotkinl | 0:2cc6bb4d7fea | 56 | ACK = 1 |
mbotkinl | 0:2cc6bb4d7fea | 57 | }; |
mbotkinl | 0:2cc6bb4d7fea | 58 | |
mbotkinl | 0:2cc6bb4d7fea | 59 | /** Create an I2C Master interface, connected to the specified pins |
mbotkinl | 0:2cc6bb4d7fea | 60 | * |
mbotkinl | 0:2cc6bb4d7fea | 61 | * @param sda I2C data line pin |
mbotkinl | 0:2cc6bb4d7fea | 62 | * @param scl I2C clock line pin |
mbotkinl | 0:2cc6bb4d7fea | 63 | */ |
mbotkinl | 0:2cc6bb4d7fea | 64 | I2C(PinName sda, PinName scl); |
mbotkinl | 0:2cc6bb4d7fea | 65 | |
mbotkinl | 0:2cc6bb4d7fea | 66 | /** Set the frequency of the I2C interface |
mbotkinl | 0:2cc6bb4d7fea | 67 | * |
mbotkinl | 0:2cc6bb4d7fea | 68 | * @param hz The bus frequency in hertz |
mbotkinl | 0:2cc6bb4d7fea | 69 | */ |
mbotkinl | 0:2cc6bb4d7fea | 70 | void frequency(int hz); |
mbotkinl | 0:2cc6bb4d7fea | 71 | |
mbotkinl | 0:2cc6bb4d7fea | 72 | /** Read from an I2C slave |
mbotkinl | 0:2cc6bb4d7fea | 73 | * |
mbotkinl | 0:2cc6bb4d7fea | 74 | * Performs a complete read transaction. The bottom bit of |
mbotkinl | 0:2cc6bb4d7fea | 75 | * the address is forced to 1 to indicate a read. |
mbotkinl | 0:2cc6bb4d7fea | 76 | * |
mbotkinl | 0:2cc6bb4d7fea | 77 | * @param address 8-bit I2C slave address [ addr | 1 ] |
mbotkinl | 0:2cc6bb4d7fea | 78 | * @param data Pointer to the byte-array to read data in to |
mbotkinl | 0:2cc6bb4d7fea | 79 | * @param length Number of bytes to read |
mbotkinl | 0:2cc6bb4d7fea | 80 | * @param repeated Repeated start, true - don't send stop at end |
mbotkinl | 0:2cc6bb4d7fea | 81 | * |
mbotkinl | 0:2cc6bb4d7fea | 82 | * @returns |
mbotkinl | 0:2cc6bb4d7fea | 83 | * 0 on success (ack), |
mbotkinl | 0:2cc6bb4d7fea | 84 | * non-0 on failure (nack) |
mbotkinl | 0:2cc6bb4d7fea | 85 | */ |
mbotkinl | 0:2cc6bb4d7fea | 86 | int read(int address, char *data, int length, bool repeated = false); |
mbotkinl | 0:2cc6bb4d7fea | 87 | |
mbotkinl | 0:2cc6bb4d7fea | 88 | /** Read a single byte from the I2C bus |
mbotkinl | 0:2cc6bb4d7fea | 89 | * |
mbotkinl | 0:2cc6bb4d7fea | 90 | * @param ack indicates if the byte is to be acknowledged (1 = acknowledge) |
mbotkinl | 0:2cc6bb4d7fea | 91 | * |
mbotkinl | 0:2cc6bb4d7fea | 92 | * @returns |
mbotkinl | 0:2cc6bb4d7fea | 93 | * the byte read |
mbotkinl | 0:2cc6bb4d7fea | 94 | */ |
mbotkinl | 0:2cc6bb4d7fea | 95 | int read(int ack); |
mbotkinl | 0:2cc6bb4d7fea | 96 | |
mbotkinl | 0:2cc6bb4d7fea | 97 | /** Write to an I2C slave |
mbotkinl | 0:2cc6bb4d7fea | 98 | * |
mbotkinl | 0:2cc6bb4d7fea | 99 | * Performs a complete write transaction. The bottom bit of |
mbotkinl | 0:2cc6bb4d7fea | 100 | * the address is forced to 0 to indicate a write. |
mbotkinl | 0:2cc6bb4d7fea | 101 | * |
mbotkinl | 0:2cc6bb4d7fea | 102 | * @param address 8-bit I2C slave address [ addr | 0 ] |
mbotkinl | 0:2cc6bb4d7fea | 103 | * @param data Pointer to the byte-array data to send |
mbotkinl | 0:2cc6bb4d7fea | 104 | * @param length Number of bytes to send |
mbotkinl | 0:2cc6bb4d7fea | 105 | * @param repeated Repeated start, true - do not send stop at end |
mbotkinl | 0:2cc6bb4d7fea | 106 | * |
mbotkinl | 0:2cc6bb4d7fea | 107 | * @returns |
mbotkinl | 0:2cc6bb4d7fea | 108 | * 0 on success (ack), |
mbotkinl | 0:2cc6bb4d7fea | 109 | * non-0 on failure (nack) |
mbotkinl | 0:2cc6bb4d7fea | 110 | */ |
mbotkinl | 0:2cc6bb4d7fea | 111 | int write(int address, const char *data, int length, bool repeated = false); |
mbotkinl | 0:2cc6bb4d7fea | 112 | |
mbotkinl | 0:2cc6bb4d7fea | 113 | /** Write single byte out on the I2C bus |
mbotkinl | 0:2cc6bb4d7fea | 114 | * |
mbotkinl | 0:2cc6bb4d7fea | 115 | * @param data data to write out on bus |
mbotkinl | 0:2cc6bb4d7fea | 116 | * |
mbotkinl | 0:2cc6bb4d7fea | 117 | * @returns |
mbotkinl | 0:2cc6bb4d7fea | 118 | * '1' if an ACK was received, |
mbotkinl | 0:2cc6bb4d7fea | 119 | * '0' otherwise |
mbotkinl | 0:2cc6bb4d7fea | 120 | */ |
mbotkinl | 0:2cc6bb4d7fea | 121 | int write(int data); |
mbotkinl | 0:2cc6bb4d7fea | 122 | |
mbotkinl | 0:2cc6bb4d7fea | 123 | /** Creates a start condition on the I2C bus |
mbotkinl | 0:2cc6bb4d7fea | 124 | */ |
mbotkinl | 0:2cc6bb4d7fea | 125 | |
mbotkinl | 0:2cc6bb4d7fea | 126 | void start(void); |
mbotkinl | 0:2cc6bb4d7fea | 127 | |
mbotkinl | 0:2cc6bb4d7fea | 128 | /** Creates a stop condition on the I2C bus |
mbotkinl | 0:2cc6bb4d7fea | 129 | */ |
mbotkinl | 0:2cc6bb4d7fea | 130 | void stop(void); |
mbotkinl | 0:2cc6bb4d7fea | 131 | |
mbotkinl | 0:2cc6bb4d7fea | 132 | protected: |
mbotkinl | 0:2cc6bb4d7fea | 133 | void aquire(); |
mbotkinl | 0:2cc6bb4d7fea | 134 | |
mbotkinl | 0:2cc6bb4d7fea | 135 | i2c_t _i2c; |
mbotkinl | 0:2cc6bb4d7fea | 136 | static I2C *_owner; |
mbotkinl | 0:2cc6bb4d7fea | 137 | int _hz; |
mbotkinl | 0:2cc6bb4d7fea | 138 | }; |
mbotkinl | 0:2cc6bb4d7fea | 139 | |
mbotkinl | 0:2cc6bb4d7fea | 140 | } // namespace mbed |
mbotkinl | 0:2cc6bb4d7fea | 141 | |
mbotkinl | 0:2cc6bb4d7fea | 142 | #endif |
mbotkinl | 0:2cc6bb4d7fea | 143 | |
mbotkinl | 0:2cc6bb4d7fea | 144 | #endif |