Diff: cpp/I2C.h

Revision:

0:fd0d7bdfcdc2

Child:

2:143cac498751

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/cpp/I2C.h	Tue Nov 20 17:24:08 2012 +0000
@@ -0,0 +1,150 @@
+/* mbed Microcontroller Library
+ * Copyright (c) 2006-2012 ARM Limited
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+#ifndef MBED_I2C_H
+#define MBED_I2C_H
+
+#include "platform.h"
+
+#if DEVICE_I2C
+
+#include "i2c_api.h"
+
+namespace mbed {
+
+/** An I2C Master, used for communicating with I2C slave devices
+ *
+ * Example:
+ * @code
+ * // 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);
+ * }
+ * @endcode
+ */
+class I2C {
+
+public:
+    enum RxStatus {
+        NoData,
+        MasterGeneralCall,
+        MasterWrite,
+        MasterRead
+    };
+
+    enum Acknowledge {
+        NoACK = 0,
+        ACK   = 1
+    };
+
+    /** Create an I2C Master interface, connected to the specified pins
+     *
+     *  @param sda I2C data line pin
+     *  @param scl I2C clock line pin
+     */
+    I2C(PinName sda, PinName scl);
+
+    /** Set the frequency of the I2C interface
+     *
+     *  @param hz The bus frequency in hertz
+     */
+    void frequency(int hz);
+
+    /** Read from an I2C slave
+     *
+     * Performs a complete read transaction. The bottom bit of
+     * the address is forced to 1 to indicate a read.
+     *
+     *  @param address 8-bit I2C slave address [ addr | 1 ]
+     *  @param data Pointer to the byte-array to read data in to 
+     *  @param length Number of bytes to read
+     *  @param repeated Repeated start, true - don't send stop at end
+     *
+     *  @returns
+     *       0 on success (ack),
+     *   non-0 on failure (nack)
+     */ 
+    int read(int address, char *data, int length, bool repeated = false);
+
+    /** Read a single byte from the I2C bus
+     *
+     *  @param ack indicates if the byte is to be acknowledged (1 = acknowledge)
+     *
+     *  @returns
+     *    the byte read
+     */
+    int read(int ack);
+
+    /** Write to an I2C slave
+     *
+     * Performs a complete write transaction. The bottom bit of
+     * the address is forced to 0 to indicate a write.
+     *
+     *  @param address 8-bit I2C slave address [ addr | 0 ]
+     *  @param data Pointer to the byte-array data to send 
+     *  @param length Number of bytes to send
+     *  @param repeated Repeated start, true - do not send stop at end
+     *
+     *  @returns
+     *       0 on success (ack),
+     *   non-0 on failure (nack)
+     */ 
+    int write(int address, const char *data, int length, bool repeated = false);
+
+    /** Write single byte out on the I2C bus
+     *
+     *  @param data data to write out on bus
+     *
+     *  @returns
+     *    '1' if an ACK was received,
+     *    '0' otherwise
+     */
+    int write(int data);
+
+    /** Creates a start condition on the I2C bus
+     */
+
+    void start(void);
+
+    /** Creates a stop condition on the I2C bus
+     */
+    void stop(void);
+
+protected:
+    void aquire();
+    
+    i2c_t _i2c;
+    static I2C  *_owner;
+    int         _hz;
+};
+
+} // namespace mbed
+
+#endif
+
+#endif