Luth Haroon / SD_modified

SD card interface

mbed-export/I2CSlave.h@0:22612ae617a0, 2012-10-08 (annotated)

Committer:
lharoon
Date:
Mon Oct 08 11:14:07 2012 +0000
Revision:
0:22612ae617a0
1st edition

Who changed what in which revision?

UserRevisionLine numberNew contents of line
lharoon 0:22612ae617a0 1 /* mbed Microcontroller Library - I2CSlave
lharoon 0:22612ae617a0 2 * Copyright (c) 2007-2011 ARM Limited. All rights reserved.
lharoon 0:22612ae617a0 3 */
lharoon 0:22612ae617a0 4
lharoon 0:22612ae617a0 5 #ifndef MBED_I2C_SLAVE_H
lharoon 0:22612ae617a0 6 #define MBED_I2C_SLAVE_H
lharoon 0:22612ae617a0 7
lharoon 0:22612ae617a0 8 #include "device.h"
lharoon 0:22612ae617a0 9
lharoon 0:22612ae617a0 10 #if DEVICE_I2CSLAVE
lharoon 0:22612ae617a0 11
lharoon 0:22612ae617a0 12 #include "platform.h"
lharoon 0:22612ae617a0 13 #include "PinNames.h"
lharoon 0:22612ae617a0 14 #include "PeripheralNames.h"
lharoon 0:22612ae617a0 15 #include "Base.h"
lharoon 0:22612ae617a0 16
lharoon 0:22612ae617a0 17 namespace mbed {
lharoon 0:22612ae617a0 18
lharoon 0:22612ae617a0 19 /* Class: I2CSlave
lharoon 0:22612ae617a0 20 * An I2C Slave, used for communicating with an I2C Master device
lharoon 0:22612ae617a0 21 *
lharoon 0:22612ae617a0 22 * Example:
lharoon 0:22612ae617a0 23 * > // Simple I2C responder
lharoon 0:22612ae617a0 24 * > #include <mbed.h>
lharoon 0:22612ae617a0 25 * >
lharoon 0:22612ae617a0 26 * > I2CSlave slave(p9, p10);
lharoon 0:22612ae617a0 27 * >
lharoon 0:22612ae617a0 28 * > int main() {
lharoon 0:22612ae617a0 29 * > char buf[10];
lharoon 0:22612ae617a0 30 * > char msg[] = "Slave!";
lharoon 0:22612ae617a0 31 * >
lharoon 0:22612ae617a0 32 * > slave.address(0xA0);
lharoon 0:22612ae617a0 33 * > while (1) {
lharoon 0:22612ae617a0 34 * > int i = slave.receive();
lharoon 0:22612ae617a0 35 * > switch (i) {
lharoon 0:22612ae617a0 36 * > case I2CSlave::ReadAddressed:
lharoon 0:22612ae617a0 37 * > slave.write(msg, strlen(msg) + 1); // Includes null char
lharoon 0:22612ae617a0 38 * > break;
lharoon 0:22612ae617a0 39 * > case I2CSlave::WriteGeneral:
lharoon 0:22612ae617a0 40 * > slave.read(buf, 10);
lharoon 0:22612ae617a0 41 * > printf("Read G: %s\n", buf);
lharoon 0:22612ae617a0 42 * > break;
lharoon 0:22612ae617a0 43 * > case I2CSlave::WriteAddressed:
lharoon 0:22612ae617a0 44 * > slave.read(buf, 10);
lharoon 0:22612ae617a0 45 * > printf("Read A: %s\n", buf);
lharoon 0:22612ae617a0 46 * > break;
lharoon 0:22612ae617a0 47 * > }
lharoon 0:22612ae617a0 48 * > for(int i = 0; i < 10; i++) buf[i] = 0; // Clear buffer
lharoon 0:22612ae617a0 49 * > }
lharoon 0:22612ae617a0 50 * > }
lharoon 0:22612ae617a0 51 * >
lharoon 0:22612ae617a0 52 */
lharoon 0:22612ae617a0 53 class I2CSlave : public Base {
lharoon 0:22612ae617a0 54
lharoon 0:22612ae617a0 55 public:
lharoon 0:22612ae617a0 56
lharoon 0:22612ae617a0 57 enum RxStatus {
lharoon 0:22612ae617a0 58 NoData = 0
lharoon 0:22612ae617a0 59 , ReadAddressed = 1
lharoon 0:22612ae617a0 60 , WriteGeneral = 2
lharoon 0:22612ae617a0 61 , WriteAddressed = 3
lharoon 0:22612ae617a0 62 };
lharoon 0:22612ae617a0 63
lharoon 0:22612ae617a0 64 /* Constructor: I2CSlave
lharoon 0:22612ae617a0 65 * Create an I2C Slave interface, connected to the specified pins.
lharoon 0:22612ae617a0 66 *
lharoon 0:22612ae617a0 67 * Variables:
lharoon 0:22612ae617a0 68 * sda - I2C data line pin
lharoon 0:22612ae617a0 69 * scl - I2C clock line pin
lharoon 0:22612ae617a0 70 */
lharoon 0:22612ae617a0 71 I2CSlave(PinName sda, PinName scl, const char *name = NULL);
lharoon 0:22612ae617a0 72
lharoon 0:22612ae617a0 73 /* Function: frequency
lharoon 0:22612ae617a0 74 * Set the frequency of the I2C interface
lharoon 0:22612ae617a0 75 *
lharoon 0:22612ae617a0 76 * Variables:
lharoon 0:22612ae617a0 77 * hz - The bus frequency in hertz
lharoon 0:22612ae617a0 78 */
lharoon 0:22612ae617a0 79 void frequency(int hz);
lharoon 0:22612ae617a0 80
lharoon 0:22612ae617a0 81 /* Function: receive
lharoon 0:22612ae617a0 82 * Checks to see if this I2C Slave has been addressed.
lharoon 0:22612ae617a0 83 *
lharoon 0:22612ae617a0 84 * Variables:
lharoon 0:22612ae617a0 85 * returns - a status indicating if the device has been addressed, and how
lharoon 0:22612ae617a0 86 * > NoData - the slave has not been addressed
lharoon 0:22612ae617a0 87 * > ReadAddressed - the master has requested a read from this slave
lharoon 0:22612ae617a0 88 * > WriteAddressed - the master is writing to this slave
lharoon 0:22612ae617a0 89 * > WriteGeneral - the master is writing to all slave
lharoon 0:22612ae617a0 90 */
lharoon 0:22612ae617a0 91 int receive(void);
lharoon 0:22612ae617a0 92
lharoon 0:22612ae617a0 93 /* Function: read
lharoon 0:22612ae617a0 94 * Read from an I2C master.
lharoon 0:22612ae617a0 95 *
lharoon 0:22612ae617a0 96 * Variables:
lharoon 0:22612ae617a0 97 * data - pointer to the byte array to read data in to
lharoon 0:22612ae617a0 98 * length - maximum number of bytes to read
lharoon 0:22612ae617a0 99 * returns - 0 on success, non-0 otherwise
lharoon 0:22612ae617a0 100 */
lharoon 0:22612ae617a0 101 int read(char *data, int length);
lharoon 0:22612ae617a0 102
lharoon 0:22612ae617a0 103 /* Function: read
lharoon 0:22612ae617a0 104 * Read a single byte from an I2C master.
lharoon 0:22612ae617a0 105 *
lharoon 0:22612ae617a0 106 * Variables:
lharoon 0:22612ae617a0 107 * returns - the byte read
lharoon 0:22612ae617a0 108 */
lharoon 0:22612ae617a0 109 int read(void);
lharoon 0:22612ae617a0 110
lharoon 0:22612ae617a0 111 /* Function: write
lharoon 0:22612ae617a0 112 * Write to an I2C master.
lharoon 0:22612ae617a0 113 *
lharoon 0:22612ae617a0 114 * Variables:
lharoon 0:22612ae617a0 115 * data - pointer to the byte array to be transmitted
lharoon 0:22612ae617a0 116 * length - the number of bytes to transmite
lharoon 0:22612ae617a0 117 * returns - a 0 on success, non-0 otherwise
lharoon 0:22612ae617a0 118 */
lharoon 0:22612ae617a0 119 int write(const char *data, int length);
lharoon 0:22612ae617a0 120
lharoon 0:22612ae617a0 121 /* Function: write
lharoon 0:22612ae617a0 122 * Write a single byte to an I2C master.
lharoon 0:22612ae617a0 123 *
lharoon 0:22612ae617a0 124 * Variables
lharoon 0:22612ae617a0 125 * data - the byte to write
lharoon 0:22612ae617a0 126 * returns - a '1' if an ACK was received, a '0' otherwise
lharoon 0:22612ae617a0 127 */
lharoon 0:22612ae617a0 128 int write(int data);
lharoon 0:22612ae617a0 129
lharoon 0:22612ae617a0 130 /* Function: address
lharoon 0:22612ae617a0 131 * Sets the I2C slave address.
lharoon 0:22612ae617a0 132 *
lharoon 0:22612ae617a0 133 * Variables
lharoon 0:22612ae617a0 134 * address - the address to set for the slave (ignoring the least
lharoon 0:22612ae617a0 135 * signifcant bit). If set to 0, the slave will only respond to the
lharoon 0:22612ae617a0 136 * general call address.
lharoon 0:22612ae617a0 137 */
lharoon 0:22612ae617a0 138 void address(int address);
lharoon 0:22612ae617a0 139
lharoon 0:22612ae617a0 140 /* Function: stop
lharoon 0:22612ae617a0 141 * Reset the I2C slave back into the known ready receiving state.
lharoon 0:22612ae617a0 142 */
lharoon 0:22612ae617a0 143 void stop(void);
lharoon 0:22612ae617a0 144
lharoon 0:22612ae617a0 145 protected:
lharoon 0:22612ae617a0 146
lharoon 0:22612ae617a0 147 I2CName _i2c;
lharoon 0:22612ae617a0 148 };
lharoon 0:22612ae617a0 149
lharoon 0:22612ae617a0 150 } // namespace mbed
lharoon 0:22612ae617a0 151
lharoon 0:22612ae617a0 152 #endif
lharoon 0:22612ae617a0 153
lharoon 0:22612ae617a0 154 #endif
lharoon 0:22612ae617a0 155