Micah B / mbed

mbed

Dependents:   DHTSensor_Test K64F_eCompass_OneNET_JW

I2CSlave.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?

UserRevisionLine numberNew contents of line
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_SLAVE_H
mbotkinl 0:2cc6bb4d7fea 17 #define MBED_I2C_SLAVE_H
mbotkinl 0:2cc6bb4d7fea 18
mbotkinl 0:2cc6bb4d7fea 19 #include "platform.h"
mbotkinl 0:2cc6bb4d7fea 20
mbotkinl 0:2cc6bb4d7fea 21 #if DEVICE_I2CSLAVE
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 Slave, used for communicating with an I2C Master device
mbotkinl 0:2cc6bb4d7fea 28 *
mbotkinl 0:2cc6bb4d7fea 29 * Example:
mbotkinl 0:2cc6bb4d7fea 30 * @code
mbotkinl 0:2cc6bb4d7fea 31 * // Simple I2C responder
mbotkinl 0:2cc6bb4d7fea 32 * #include <mbed.h>
mbotkinl 0:2cc6bb4d7fea 33 *
mbotkinl 0:2cc6bb4d7fea 34 * I2CSlave slave(p9, p10);
mbotkinl 0:2cc6bb4d7fea 35 *
mbotkinl 0:2cc6bb4d7fea 36 * int main() {
mbotkinl 0:2cc6bb4d7fea 37 * char buf[10];
mbotkinl 0:2cc6bb4d7fea 38 * char msg[] = "Slave!";
mbotkinl 0:2cc6bb4d7fea 39 *
mbotkinl 0:2cc6bb4d7fea 40 * slave.address(0xA0);
mbotkinl 0:2cc6bb4d7fea 41 * while (1) {
mbotkinl 0:2cc6bb4d7fea 42 * int i = slave.receive();
mbotkinl 0:2cc6bb4d7fea 43 * switch (i) {
mbotkinl 0:2cc6bb4d7fea 44 * case I2CSlave::ReadAddressed:
mbotkinl 0:2cc6bb4d7fea 45 * slave.write(msg, strlen(msg) + 1); // Includes null char
mbotkinl 0:2cc6bb4d7fea 46 * break;
mbotkinl 0:2cc6bb4d7fea 47 * case I2CSlave::WriteGeneral:
mbotkinl 0:2cc6bb4d7fea 48 * slave.read(buf, 10);
mbotkinl 0:2cc6bb4d7fea 49 * printf("Read G: %s\n", buf);
mbotkinl 0:2cc6bb4d7fea 50 * break;
mbotkinl 0:2cc6bb4d7fea 51 * case I2CSlave::WriteAddressed:
mbotkinl 0:2cc6bb4d7fea 52 * slave.read(buf, 10);
mbotkinl 0:2cc6bb4d7fea 53 * printf("Read A: %s\n", buf);
mbotkinl 0:2cc6bb4d7fea 54 * break;
mbotkinl 0:2cc6bb4d7fea 55 * }
mbotkinl 0:2cc6bb4d7fea 56 * for(int i = 0; i < 10; i++) buf[i] = 0; // Clear buffer
mbotkinl 0:2cc6bb4d7fea 57 * }
mbotkinl 0:2cc6bb4d7fea 58 * }
mbotkinl 0:2cc6bb4d7fea 59 * @endcode
mbotkinl 0:2cc6bb4d7fea 60 */
mbotkinl 0:2cc6bb4d7fea 61 class I2CSlave {
mbotkinl 0:2cc6bb4d7fea 62
mbotkinl 0:2cc6bb4d7fea 63 public:
mbotkinl 0:2cc6bb4d7fea 64 enum RxStatus {
mbotkinl 0:2cc6bb4d7fea 65 NoData = 0,
mbotkinl 0:2cc6bb4d7fea 66 ReadAddressed = 1,
mbotkinl 0:2cc6bb4d7fea 67 WriteGeneral = 2,
mbotkinl 0:2cc6bb4d7fea 68 WriteAddressed = 3
mbotkinl 0:2cc6bb4d7fea 69 };
mbotkinl 0:2cc6bb4d7fea 70
mbotkinl 0:2cc6bb4d7fea 71 /** Create an I2C Slave interface, connected to the specified pins.
mbotkinl 0:2cc6bb4d7fea 72 *
mbotkinl 0:2cc6bb4d7fea 73 * @param sda I2C data line pin
mbotkinl 0:2cc6bb4d7fea 74 * @param scl I2C clock line pin
mbotkinl 0:2cc6bb4d7fea 75 */
mbotkinl 0:2cc6bb4d7fea 76 I2CSlave(PinName sda, PinName scl);
mbotkinl 0:2cc6bb4d7fea 77
mbotkinl 0:2cc6bb4d7fea 78 /** Set the frequency of the I2C interface
mbotkinl 0:2cc6bb4d7fea 79 *
mbotkinl 0:2cc6bb4d7fea 80 * @param hz The bus frequency in hertz
mbotkinl 0:2cc6bb4d7fea 81 */
mbotkinl 0:2cc6bb4d7fea 82 void frequency(int hz);
mbotkinl 0:2cc6bb4d7fea 83
mbotkinl 0:2cc6bb4d7fea 84 /** Checks to see if this I2C Slave has been addressed.
mbotkinl 0:2cc6bb4d7fea 85 *
mbotkinl 0:2cc6bb4d7fea 86 * @returns
mbotkinl 0:2cc6bb4d7fea 87 * A status indicating if the device has been addressed, and how
mbotkinl 0:2cc6bb4d7fea 88 * - NoData - the slave has not been addressed
mbotkinl 0:2cc6bb4d7fea 89 * - ReadAddressed - the master has requested a read from this slave
mbotkinl 0:2cc6bb4d7fea 90 * - WriteAddressed - the master is writing to this slave
mbotkinl 0:2cc6bb4d7fea 91 * - WriteGeneral - the master is writing to all slave
mbotkinl 0:2cc6bb4d7fea 92 */
mbotkinl 0:2cc6bb4d7fea 93 int receive(void);
mbotkinl 0:2cc6bb4d7fea 94
mbotkinl 0:2cc6bb4d7fea 95 /** Read from an I2C master.
mbotkinl 0:2cc6bb4d7fea 96 *
mbotkinl 0:2cc6bb4d7fea 97 * @param data pointer to the byte array to read data in to
mbotkinl 0:2cc6bb4d7fea 98 * @param length maximum number of bytes to read
mbotkinl 0:2cc6bb4d7fea 99 *
mbotkinl 0:2cc6bb4d7fea 100 * @returns
mbotkinl 0:2cc6bb4d7fea 101 * 0 on success,
mbotkinl 0:2cc6bb4d7fea 102 * non-0 otherwise
mbotkinl 0:2cc6bb4d7fea 103 */
mbotkinl 0:2cc6bb4d7fea 104 int read(char *data, int length);
mbotkinl 0:2cc6bb4d7fea 105
mbotkinl 0:2cc6bb4d7fea 106 /** Read a single byte from an I2C master.
mbotkinl 0:2cc6bb4d7fea 107 *
mbotkinl 0:2cc6bb4d7fea 108 * @returns
mbotkinl 0:2cc6bb4d7fea 109 * the byte read
mbotkinl 0:2cc6bb4d7fea 110 */
mbotkinl 0:2cc6bb4d7fea 111 int read(void);
mbotkinl 0:2cc6bb4d7fea 112
mbotkinl 0:2cc6bb4d7fea 113 /** Write to an I2C master.
mbotkinl 0:2cc6bb4d7fea 114 *
mbotkinl 0:2cc6bb4d7fea 115 * @param data pointer to the byte array to be transmitted
mbotkinl 0:2cc6bb4d7fea 116 * @param length the number of bytes to transmite
mbotkinl 0:2cc6bb4d7fea 117 *
mbotkinl 0:2cc6bb4d7fea 118 * @returns
mbotkinl 0:2cc6bb4d7fea 119 * 0 on success,
mbotkinl 0:2cc6bb4d7fea 120 * non-0 otherwise
mbotkinl 0:2cc6bb4d7fea 121 */
mbotkinl 0:2cc6bb4d7fea 122 int write(const char *data, int length);
mbotkinl 0:2cc6bb4d7fea 123
mbotkinl 0:2cc6bb4d7fea 124 /** Write a single byte to an I2C master.
mbotkinl 0:2cc6bb4d7fea 125 *
mbotkinl 0:2cc6bb4d7fea 126 * @data the byte to write
mbotkinl 0:2cc6bb4d7fea 127 *
mbotkinl 0:2cc6bb4d7fea 128 * @returns
mbotkinl 0:2cc6bb4d7fea 129 * '1' if an ACK was received,
mbotkinl 0:2cc6bb4d7fea 130 * '0' otherwise
mbotkinl 0:2cc6bb4d7fea 131 */
mbotkinl 0:2cc6bb4d7fea 132 int write(int data);
mbotkinl 0:2cc6bb4d7fea 133
mbotkinl 0:2cc6bb4d7fea 134 /** Sets the I2C slave address.
mbotkinl 0:2cc6bb4d7fea 135 *
mbotkinl 0:2cc6bb4d7fea 136 * @param address The address to set for the slave (ignoring the least
mbotkinl 0:2cc6bb4d7fea 137 * signifcant bit). If set to 0, the slave will only respond to the
mbotkinl 0:2cc6bb4d7fea 138 * general call address.
mbotkinl 0:2cc6bb4d7fea 139 */
mbotkinl 0:2cc6bb4d7fea 140 void address(int address);
mbotkinl 0:2cc6bb4d7fea 141
mbotkinl 0:2cc6bb4d7fea 142 /** Reset the I2C slave back into the known ready receiving state.
mbotkinl 0:2cc6bb4d7fea 143 */
mbotkinl 0:2cc6bb4d7fea 144 void stop(void);
mbotkinl 0:2cc6bb4d7fea 145
mbotkinl 0:2cc6bb4d7fea 146 protected:
mbotkinl 0:2cc6bb4d7fea 147 i2c_t _i2c;
mbotkinl 0:2cc6bb4d7fea 148 };
mbotkinl 0:2cc6bb4d7fea 149
mbotkinl 0:2cc6bb4d7fea 150 } // namespace mbed
mbotkinl 0:2cc6bb4d7fea 151
mbotkinl 0:2cc6bb4d7fea 152 #endif
mbotkinl 0:2cc6bb4d7fea 153
mbotkinl 0:2cc6bb4d7fea 154 #endif