航空研究会 / mbed

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I2CSlave.h@22:9114680c05da, 2010-07-08 (annotated)

Committer:
simon
Date:
Thu Jul 08 14:27:15 2010 +0000
Revision:
22:9114680c05da
Child:
27:7110ebee3484
* CAN updates

 * I2CSlave

 * I2C and Ethernet bugfixes

Who changed what in which revision?

UserRevisionLine numberNew contents of line
simon 22:9114680c05da 1 /* mbed Microcontroller Library - I2CSlave
simon 22:9114680c05da 2 * Copyright (c) 2007-2010 ARM Limited. All rights reserved.
simon 22:9114680c05da 3 * jward
simon 22:9114680c05da 4 */
simon 22:9114680c05da 5
simon 22:9114680c05da 6 #ifndef MBED_I2C_SLAVE_H
simon 22:9114680c05da 7 #define MBED_I2C_SLAVE_H
simon 22:9114680c05da 8
simon 22:9114680c05da 9 #include "platform.h"
simon 22:9114680c05da 10 #include "PinNames.h"
simon 22:9114680c05da 11 #include "PeripheralNames.h"
simon 22:9114680c05da 12 #include "Base.h"
simon 22:9114680c05da 13
simon 22:9114680c05da 14 namespace mbed {
simon 22:9114680c05da 15
simon 22:9114680c05da 16 /* Class: I2CSlave
simon 22:9114680c05da 17 * An I2C Slave, used for communicating with an I2C Master device
simon 22:9114680c05da 18 *
simon 22:9114680c05da 19 * Example:
simon 22:9114680c05da 20 * > // Simple I2C responder
simon 22:9114680c05da 21 * > #include <mbed.h>
simon 22:9114680c05da 22 * >
simon 22:9114680c05da 23 * > I2CSlave slave(p9, p10);
simon 22:9114680c05da 24 * >
simon 22:9114680c05da 25 * > int main() {
simon 22:9114680c05da 26 * > char buf[10];
simon 22:9114680c05da 27 * > char msg[] = "Slave!";
simon 22:9114680c05da 28 * >
simon 22:9114680c05da 29 * > slave.address(0xA0);
simon 22:9114680c05da 30 * > while (1) {
simon 22:9114680c05da 31 * > int i = slave.receive();
simon 22:9114680c05da 32 * > switch (i) {
simon 22:9114680c05da 33 * > case I2CSlave::ReadAddressed:
simon 22:9114680c05da 34 * > slave.write(msg, strlen(msg) + 1); // Includes null char
simon 22:9114680c05da 35 * > break;
simon 22:9114680c05da 36 * > case I2CSlave::WriteGeneral:
simon 22:9114680c05da 37 * > slave.read(buf, 10);
simon 22:9114680c05da 38 * > printf("Read G: %s\n", buf);
simon 22:9114680c05da 39 * > break;
simon 22:9114680c05da 40 * > case I2CSlave::WriteAddressed:
simon 22:9114680c05da 41 * > slave.read(buf, 10);
simon 22:9114680c05da 42 * > printf("Read A: %s\n", buf);
simon 22:9114680c05da 43 * > break;
simon 22:9114680c05da 44 * > }
simon 22:9114680c05da 45 * > for(int i = 0; i < 10; i++) buf[i] = 0; // Clear buffer
simon 22:9114680c05da 46 * > }
simon 22:9114680c05da 47 * > }
simon 22:9114680c05da 48 * >
simon 22:9114680c05da 49 */
simon 22:9114680c05da 50 class I2CSlave : public Base {
simon 22:9114680c05da 51
simon 22:9114680c05da 52 public:
simon 22:9114680c05da 53
simon 22:9114680c05da 54 enum RxStatus {
simon 22:9114680c05da 55 NoData = 0
simon 22:9114680c05da 56 , ReadAddressed = 1
simon 22:9114680c05da 57 , WriteGeneral = 2
simon 22:9114680c05da 58 , WriteAddressed = 3
simon 22:9114680c05da 59 };
simon 22:9114680c05da 60
simon 22:9114680c05da 61 /* Constructor: I2CSlave
simon 22:9114680c05da 62 * Create an I2C Slave interface, connected to the specified pins.
simon 22:9114680c05da 63 *
simon 22:9114680c05da 64 * Variables:
simon 22:9114680c05da 65 * sda - I2C data line pin
simon 22:9114680c05da 66 * scl - I2C clock line pin
simon 22:9114680c05da 67 */
simon 22:9114680c05da 68 I2CSlave(PinName sda, PinName scl, const char *name = NULL);
simon 22:9114680c05da 69
simon 22:9114680c05da 70 /* Function: frequency
simon 22:9114680c05da 71 * Set the frequency of the I2C interface
simon 22:9114680c05da 72 *
simon 22:9114680c05da 73 * Variables:
simon 22:9114680c05da 74 * hz - The bus frequency in hertz
simon 22:9114680c05da 75 */
simon 22:9114680c05da 76 void frequency(int hz);
simon 22:9114680c05da 77
simon 22:9114680c05da 78 /* Function: receive
simon 22:9114680c05da 79 * Checks to see if this I2C Slave has been addressed.
simon 22:9114680c05da 80 *
simon 22:9114680c05da 81 * Variables:
simon 22:9114680c05da 82 * returns - a status indicating if the device has been addressed, and how
simon 22:9114680c05da 83 * > NoData - the slave has not been addressed
simon 22:9114680c05da 84 * > ReadAddressed - the master has requested a read from this slave
simon 22:9114680c05da 85 * > WriteAddressed - the master is writing to this slave
simon 22:9114680c05da 86 * > WriteGeneral - the master is writing to all slave
simon 22:9114680c05da 87 */
simon 22:9114680c05da 88 int receive(void);
simon 22:9114680c05da 89
simon 22:9114680c05da 90 /* Function: read
simon 22:9114680c05da 91 * Read from an I2C master.
simon 22:9114680c05da 92 *
simon 22:9114680c05da 93 * Variables:
simon 22:9114680c05da 94 * data - pointer to the byte array to read data in to
simon 22:9114680c05da 95 * length - maximum number of bytes to read
simon 22:9114680c05da 96 * returns - 0 on success, non-0 otherwise
simon 22:9114680c05da 97 */
simon 22:9114680c05da 98 int read(char *data, int length);
simon 22:9114680c05da 99
simon 22:9114680c05da 100 /* Function: read
simon 22:9114680c05da 101 * Read a single byte from an I2C master.
simon 22:9114680c05da 102 *
simon 22:9114680c05da 103 * Variables:
simon 22:9114680c05da 104 * returns - the byte read
simon 22:9114680c05da 105 */
simon 22:9114680c05da 106 int read(void);
simon 22:9114680c05da 107
simon 22:9114680c05da 108 /* Function: write
simon 22:9114680c05da 109 * Write to an I2C master.
simon 22:9114680c05da 110 *
simon 22:9114680c05da 111 * Variables:
simon 22:9114680c05da 112 * data - pointer to the byte array to be transmitted
simon 22:9114680c05da 113 * length - the number of bytes to transmite
simon 22:9114680c05da 114 * returns - a 0 on success, non-0 otherwise
simon 22:9114680c05da 115 */
simon 22:9114680c05da 116 int write(const char *data, int length);
simon 22:9114680c05da 117
simon 22:9114680c05da 118 /* Function: write
simon 22:9114680c05da 119 * Write a single byte to an I2C master.
simon 22:9114680c05da 120 *
simon 22:9114680c05da 121 * Variables
simon 22:9114680c05da 122 * data - the byte to write
simon 22:9114680c05da 123 * returns - a '1' if an ACK was received, a '0' otherwise
simon 22:9114680c05da 124 */
simon 22:9114680c05da 125 int write(int data);
simon 22:9114680c05da 126
simon 22:9114680c05da 127 /* Function: address
simon 22:9114680c05da 128 * Sets the I2C slave address.
simon 22:9114680c05da 129 *
simon 22:9114680c05da 130 * Variables
simon 22:9114680c05da 131 * address - the address to set for the slave (ignoring the least
simon 22:9114680c05da 132 * signifcant bit). If set to 0, the slave will only respond to the
simon 22:9114680c05da 133 * general call address.
simon 22:9114680c05da 134 */
simon 22:9114680c05da 135 void address(int address);
simon 22:9114680c05da 136
simon 22:9114680c05da 137 /* Function: stop
simon 22:9114680c05da 138 * Reset the I2C slave back into the known ready receiving state.
simon 22:9114680c05da 139 */
simon 22:9114680c05da 140 void stop(void);
simon 22:9114680c05da 141
simon 22:9114680c05da 142 protected:
simon 22:9114680c05da 143
simon 22:9114680c05da 144 I2CName _i2c;
simon 22:9114680c05da 145 };
simon 22:9114680c05da 146
simon 22:9114680c05da 147 } // namespace mbed
simon 22:9114680c05da 148
simon 22:9114680c05da 149 #endif