Diff: I2CSlave.h

Revision:

0:a8fa94490a0a

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/I2CSlave.h	Sat Sep 22 10:32:07 2012 +0000
@@ -0,0 +1,155 @@
+/* mbed Microcontroller Library - I2CSlave
+ * Copyright (c) 2007-2011 ARM Limited. All rights reserved.
+ */ 
+ 
+#ifndef MBED_I2C_SLAVE_H
+#define MBED_I2C_SLAVE_H
+
+#include "device.h"
+
+#if DEVICE_I2CSLAVE
+
+#include "platform.h"
+#include "PinNames.h"
+#include "PeripheralNames.h"
+#include "Base.h"
+
+namespace mbed {
+
+/* Class: I2CSlave
+ *  An I2C Slave, used for communicating with an I2C Master device
+ *
+ * Example:
+ * > // Simple I2C responder
+ * > #include <mbed.h>
+ * >
+ * > I2CSlave slave(p9, p10);
+ * >
+ * > int main() {
+ * >     char buf[10];
+ * >     char msg[] = "Slave!";
+ * >
+ * >     slave.address(0xA0);
+ * >     while (1) {
+ * >         int i = slave.receive();
+ * >         switch (i) {
+ * >             case I2CSlave::ReadAddressed: 
+ * >                 slave.write(msg, strlen(msg) + 1); // Includes null char
+ * >                 break;
+ * >             case I2CSlave::WriteGeneral:
+ * >                 slave.read(buf, 10);
+ * >                 printf("Read G: %s\n", buf);
+ * >                 break;
+ * >             case I2CSlave::WriteAddressed:
+ * >                 slave.read(buf, 10);
+ * >                 printf("Read A: %s\n", buf);
+ * >                 break;
+ * >         }
+ * >         for(int i = 0; i < 10; i++) buf[i] = 0;    // Clear buffer
+ * >     }
+ * > }
+ * >                  
+ */
+class I2CSlave : public Base {
+
+public:
+    
+    enum RxStatus {
+        NoData              = 0
+        , ReadAddressed     = 1
+        , WriteGeneral      = 2
+        , WriteAddressed    = 3
+    };
+
+    /* Constructor: I2CSlave
+     *  Create an I2C Slave interface, connected to the specified pins.
+     *
+     * Variables:
+     *  sda - I2C data line pin
+     *  scl - I2C clock line pin
+     */
+    I2CSlave(PinName sda, PinName scl, const char *name = NULL);
+
+    /* Function: frequency
+     *  Set the frequency of the I2C interface
+     *
+     * Variables:
+     *  hz - The bus frequency in hertz
+     */
+    void frequency(int hz);
+
+    /* Function: receive
+     *  Checks to see if this I2C Slave has been addressed.
+     *
+     * Variables:
+     *  returns - a status indicating if the device has been addressed, and how
+     *  > NoData            - the slave has not been addressed
+     *  > ReadAddressed     - the master has requested a read from this slave
+     *  > WriteAddressed    - the master is writing to this slave
+     *  > WriteGeneral      - the master is writing to all slave 
+     */
+    int receive(void);
+
+    /* Function: read
+     *  Read from an I2C master.
+     *
+     * Variables:
+     *  data - pointer to the byte array to read data in to
+     *  length - maximum number of bytes to read
+     *  returns - 0 on success, non-0 otherwise
+     */
+    int read(char *data, int length); 
+
+    /* Function: read
+     *  Read a single byte from an I2C master.
+     *
+     * Variables:
+     *  returns - the byte read
+     */
+    int read(void);
+
+    /* Function: write
+     *  Write to an I2C master.
+     *
+     * Variables:
+     *  data - pointer to the byte array to be transmitted
+     *  length - the number of bytes to transmite
+     *  returns - a 0 on success, non-0 otherwise
+     */
+    int write(const char *data, int length);
+
+    /* Function: write
+     *  Write a single byte to an I2C master.
+     *
+     * Variables
+     *  data - the byte to write
+     *  returns - a '1' if an ACK was received, a '0' otherwise
+     */
+    int write(int data);
+
+    /* Function: address
+     *  Sets the I2C slave address.
+     *
+     * Variables
+     *  address - the address to set for the slave (ignoring the least
+     *  signifcant bit). If set to 0, the slave will only respond to the
+     *  general call address.
+     */
+    void address(int address);
+
+    /* Function: stop
+     *  Reset the I2C slave back into the known ready receiving state.
+     */
+    void stop(void);
+
+protected:
+
+    I2CName     _i2c;
+};
+
+} // namespace mbed
+
+#endif
+
+#endif
+