ju Lei / mbed

The official mbed C/C SDK provides the software platform and libraries to build your applications.

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I2C.h@64:75c1708b266b, 2013-07-05 (annotated)

Committer:
ldyz
Date:
Fri Jul 05 13:16:13 2013 +0000
Revision:
64:75c1708b266b
Parent:
59:0883845fe643 
test

Who changed what in which revision?

UserRevisionLine numberNew contents of line
emilmont 44:24d45a770a51 1 /* mbed Microcontroller Library
emilmont 54:71b101360fb9 2 * Copyright (c) 2006-2013 ARM Limited
emilmont 44:24d45a770a51 3 *
emilmont 59:0883845fe643 4 * Licensed under the Apache License, Version 2.0 (the "License");
emilmont 59:0883845fe643 5 * you may not use this file except in compliance with the License.
emilmont 59:0883845fe643 6 * You may obtain a copy of the License at
emilmont 59:0883845fe643 7 *
emilmont 59:0883845fe643 8 * http://www.apache.org/licenses/LICENSE-2.0
emilmont 44:24d45a770a51 9 *
emilmont 59:0883845fe643 10 * Unless required by applicable law or agreed to in writing, software
emilmont 59:0883845fe643 11 * distributed under the License is distributed on an "AS IS" BASIS,
emilmont 59:0883845fe643 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
emilmont 59:0883845fe643 13 * See the License for the specific language governing permissions and
emilmont 59:0883845fe643 14 * limitations under the License.
emilmont 44:24d45a770a51 15 */
simon.ford@mbed.co.uk 0:82220227f4fa 16 #ifndef MBED_I2C_H
simon.ford@mbed.co.uk 0:82220227f4fa 17 #define MBED_I2C_H
simon.ford@mbed.co.uk 0:82220227f4fa 18
emilmont 44:24d45a770a51 19 #include "platform.h"
emilmont 27:7110ebee3484 20
emilmont 27:7110ebee3484 21 #if DEVICE_I2C
emilmont 27:7110ebee3484 22
emilmont 44:24d45a770a51 23 #include "i2c_api.h"
simon.ford@mbed.co.uk 0:82220227f4fa 24
simon.ford@mbed.co.uk 0:82220227f4fa 25 namespace mbed {
simon.ford@mbed.co.uk 0:82220227f4fa 26
emilmont 43:e2ed12d17f06 27 /** An I2C Master, used for communicating with I2C slave devices
rolf.meyer@arm.com 11:1c1ebd0324fa 28 *
rolf.meyer@arm.com 11:1c1ebd0324fa 29 * Example:
emilmont 43:e2ed12d17f06 30 * @code
emilmont 43:e2ed12d17f06 31 * // Read from I2C slave at address 0x62
emilmont 43:e2ed12d17f06 32 *
emilmont 43:e2ed12d17f06 33 * #include "mbed.h"
emilmont 43:e2ed12d17f06 34 *
emilmont 43:e2ed12d17f06 35 * I2C i2c(p28, p27);
emilmont 43:e2ed12d17f06 36 *
emilmont 43:e2ed12d17f06 37 * int main() {
emilmont 43:e2ed12d17f06 38 * int address = 0x62;
emilmont 43:e2ed12d17f06 39 * char data[2];
emilmont 43:e2ed12d17f06 40 * i2c.read(address, data, 2);
emilmont 43:e2ed12d17f06 41 * }
emilmont 43:e2ed12d17f06 42 * @endcode
simon.ford@mbed.co.uk 0:82220227f4fa 43 */
emilmont 44:24d45a770a51 44 class I2C {
simon.ford@mbed.co.uk 0:82220227f4fa 45
simon.ford@mbed.co.uk 0:82220227f4fa 46 public:
simon 20:029aa53d7323 47 enum RxStatus {
emilmont 44:24d45a770a51 48 NoData,
emilmont 44:24d45a770a51 49 MasterGeneralCall,
emilmont 44:24d45a770a51 50 MasterWrite,
emilmont 44:24d45a770a51 51 MasterRead
simon 20:029aa53d7323 52 };
simon 20:029aa53d7323 53
simon 21:3944f1e2fa4f 54 enum Acknowledge {
emilmont 44:24d45a770a51 55 NoACK = 0,
emilmont 44:24d45a770a51 56 ACK = 1
simon 21:3944f1e2fa4f 57 };
simon 21:3944f1e2fa4f 58
emilmont 43:e2ed12d17f06 59 /** Create an I2C Master interface, connected to the specified pins
rolf.meyer@arm.com 11:1c1ebd0324fa 60 *
emilmont 43:e2ed12d17f06 61 * @param sda I2C data line pin
emilmont 43:e2ed12d17f06 62 * @param scl I2C clock line pin
rolf.meyer@arm.com 11:1c1ebd0324fa 63 */
emilmont 44:24d45a770a51 64 I2C(PinName sda, PinName scl);
simon.ford@mbed.co.uk 0:82220227f4fa 65
emilmont 43:e2ed12d17f06 66 /** Set the frequency of the I2C interface
rolf.meyer@arm.com 11:1c1ebd0324fa 67 *
emilmont 43:e2ed12d17f06 68 * @param hz The bus frequency in hertz
rolf.meyer@arm.com 11:1c1ebd0324fa 69 */
rolf.meyer@arm.com 11:1c1ebd0324fa 70 void frequency(int hz);
rolf.meyer@arm.com 11:1c1ebd0324fa 71
emilmont 43:e2ed12d17f06 72 /** Read from an I2C slave
simon.ford@mbed.co.uk 0:82220227f4fa 73 *
emilmont 44:24d45a770a51 74 * Performs a complete read transaction. The bottom bit of
emilmont 44:24d45a770a51 75 * the address is forced to 1 to indicate a read.
rolf.meyer@arm.com 12:f63353af7be8 76 *
emilmont 43:e2ed12d17f06 77 * @param address 8-bit I2C slave address [ addr | 1 ]
emilmont 55:d722ed6a4237 78 * @param data Pointer to the byte-array to read data in to
emilmont 43:e2ed12d17f06 79 * @param length Number of bytes to read
emilmont 43:e2ed12d17f06 80 * @param repeated Repeated start, true - don't send stop at end
emilmont 43:e2ed12d17f06 81 *
emilmont 43:e2ed12d17f06 82 * @returns
emilmont 43:e2ed12d17f06 83 * 0 on success (ack),
emilmont 43:e2ed12d17f06 84 * non-0 on failure (nack)
emilmont 55:d722ed6a4237 85 */
emilmont 44:24d45a770a51 86 int read(int address, char *data, int length, bool repeated = false);
simon.ford@mbed.co.uk 0:82220227f4fa 87
emilmont 43:e2ed12d17f06 88 /** Read a single byte from the I2C bus
simon 21:3944f1e2fa4f 89 *
emilmont 43:e2ed12d17f06 90 * @param ack indicates if the byte is to be acknowledged (1 = acknowledge)
emilmont 43:e2ed12d17f06 91 *
emilmont 43:e2ed12d17f06 92 * @returns
emilmont 43:e2ed12d17f06 93 * the byte read
simon 21:3944f1e2fa4f 94 */
simon 21:3944f1e2fa4f 95 int read(int ack);
simon 21:3944f1e2fa4f 96
emilmont 43:e2ed12d17f06 97 /** Write to an I2C slave
rolf.meyer@arm.com 11:1c1ebd0324fa 98 *
emilmont 44:24d45a770a51 99 * Performs a complete write transaction. The bottom bit of
emilmont 44:24d45a770a51 100 * the address is forced to 0 to indicate a write.
rolf.meyer@arm.com 12:f63353af7be8 101 *
emilmont 43:e2ed12d17f06 102 * @param address 8-bit I2C slave address [ addr | 0 ]
emilmont 55:d722ed6a4237 103 * @param data Pointer to the byte-array data to send
emilmont 43:e2ed12d17f06 104 * @param length Number of bytes to send
emilmont 43:e2ed12d17f06 105 * @param repeated Repeated start, true - do not send stop at end
emilmont 43:e2ed12d17f06 106 *
emilmont 43:e2ed12d17f06 107 * @returns
emilmont 43:e2ed12d17f06 108 * 0 on success (ack),
emilmont 43:e2ed12d17f06 109 * non-0 on failure (nack)
emilmont 55:d722ed6a4237 110 */
simon 20:029aa53d7323 111 int write(int address, const char *data, int length, bool repeated = false);
simon 21:3944f1e2fa4f 112
emilmont 43:e2ed12d17f06 113 /** Write single byte out on the I2C bus
emilmont 43:e2ed12d17f06 114 *
emilmont 43:e2ed12d17f06 115 * @param data data to write out on bus
simon 21:3944f1e2fa4f 116 *
emilmont 43:e2ed12d17f06 117 * @returns
emilmont 43:e2ed12d17f06 118 * '1' if an ACK was received,
emilmont 43:e2ed12d17f06 119 * '0' otherwise
simon 21:3944f1e2fa4f 120 */
simon 21:3944f1e2fa4f 121 int write(int data);
simon 21:3944f1e2fa4f 122
emilmont 43:e2ed12d17f06 123 /** Creates a start condition on the I2C bus
simon 21:3944f1e2fa4f 124 */
emilmont 44:24d45a770a51 125
simon 21:3944f1e2fa4f 126 void start(void);
simon 21:3944f1e2fa4f 127
emilmont 43:e2ed12d17f06 128 /** Creates a stop condition on the I2C bus
simon 21:3944f1e2fa4f 129 */
simon 21:3944f1e2fa4f 130 void stop(void);
simon 21:3944f1e2fa4f 131
simon.ford@mbed.co.uk 0:82220227f4fa 132 protected:
rolf.meyer@arm.com 11:1c1ebd0324fa 133 void aquire();
emilmont 55:d722ed6a4237 134
emilmont 44:24d45a770a51 135 i2c_t _i2c;
simon 20:029aa53d7323 136 static I2C *_owner;
simon 20:029aa53d7323 137 int _hz;
simon.ford@mbed.co.uk 0:82220227f4fa 138 };
simon.ford@mbed.co.uk 0:82220227f4fa 139
rolf.meyer@arm.com 11:1c1ebd0324fa 140 } // namespace mbed
simon.ford@mbed.co.uk 0:82220227f4fa 141
simon.ford@mbed.co.uk 1:6b7f447ca868 142 #endif
emilmont 27:7110ebee3484 143
emilmont 27:7110ebee3484 144 #endif