Diff: I2C.h

Revision:

0:a8fa94490a0a

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/I2C.h	Sat Sep 22 10:32:07 2012 +0000
@@ -0,0 +1,142 @@
+/* mbed Microcontroller Library - I2C
+ * Copyright (c) 2007-2011 ARM Limited. All rights reserved.
+ */ 
+ 
+#ifndef MBED_I2C_H
+#define MBED_I2C_H
+
+#include "device.h"
+
+#if DEVICE_I2C
+
+#include "platform.h"
+#include "PinNames.h"
+#include "PeripheralNames.h"
+#include "Base.h"
+
+namespace mbed {
+
+/* Class: I2C
+ *  An I2C Master, used for communicating with I2C slave devices
+ *
+ * Example:
+ * > // Read from I2C slave at address 0x62
+ * >
+ * > #include "mbed.h"
+ * >
+ * > I2C i2c(p28, p27);
+ * >
+ * > int main() {
+ * >     int address = 0x62;
+ * >     char data[2];
+ * >     i2c.read(address, data, 2);
+ * > }
+ */
+class I2C : public Base {
+
+public:
+
+    enum RxStatus {
+        NoData
+        , MasterGeneralCall
+        , MasterWrite
+        , MasterRead
+    };
+
+    enum Acknowledge {
+          NoACK = 0
+        , ACK   = 1
+    };
+
+    /* Constructor: I2C
+     *  Create an I2C Master interface, connected to the specified pins
+     *
+     * Variables:
+     *  sda - I2C data line pin
+     *  scl - I2C clock line pin
+     */
+    I2C(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: read
+     *  Read from an I2C slave
+     *
+     * Performs a complete read transaction. The bottom bit of
+     * the address is forced to 1 to indicate a read.
+     *
+     * Variables:
+     *  address - 8-bit I2C slave address [ addr | 1 ]
+     *  data - Pointer to the byte-array to read data in to 
+     *  length - Number of bytes to read
+     *  repeated - Repeated start, true - don't send stop at end
+     *  returns - 0 on success (ack), or non-0 on failure (nack)
+     */ 
+    int read(int address, char *data, int length, bool repeated = false); 
+
+    /* Function: read
+     *  Read a single byte from the I2C bus
+     *
+     * Variables:
+     *  ack - indicates if the byte is to be acknowledged (1 = acknowledge)
+     *  returns - the byte read
+     */
+    int read(int ack);
+
+    /* Function: write
+     *  Write to an I2C slave
+     *
+     * Performs a complete write transaction. The bottom bit of
+     * the address is forced to 0 to indicate a write.
+     *
+     * Variables:
+     *  address - 8-bit I2C slave address [ addr | 0 ]
+     *  data - Pointer to the byte-array data to send 
+     *  length - Number of bytes to send
+     *  repeated - Repeated start, true - do not send stop at end
+     *  returns - 0 on success (ack), or non-0 on failure (nack)
+     */ 
+    int write(int address, const char *data, int length, bool repeated = false);
+
+    /* Function: write
+     *  Write single byte out on the I2C bus
+     *
+     * Variables:
+     *  data - data to write out on bus
+     *  returns - a '1' if an ACK was received, a '0' otherwise
+     */
+    int write(int data);
+
+    /* Function: start
+     *  Creates a start condition on the I2C bus
+     */
+
+    void start(void);
+
+    /* Function: stop
+     *  Creates a stop condition on the I2C bus
+     */
+    void stop(void);
+
+protected:
+
+    void aquire();
+
+    I2CName     _i2c;
+    static I2C  *_owner;
+    int         _hz;
+
+};
+
+} // namespace mbed
+
+#endif
+
+#endif
+