Diff: DevI2C/DevI2C.h

Revision:

0:5f1934431e71

Child:

1:ca975408dd4e

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/DevI2C/DevI2C.h	Mon Mar 30 11:46:53 2015 +0200
@@ -0,0 +1,123 @@
+/**
+ ******************************************************************************
+ * @file    DevI2C.h
+ * @author  AST / EST
+ * @version V0.0.1
+ * @date    21-January-2015
+ * @brief   Header file for a special I2C class DecI2C which provides some
+ *          helper function for on-board communication
+ ******************************************************************************
+ * @attention
+ *
+ * <h2><center>&copy; COPYRIGHT(c) 2014 STMicroelectronics</center></h2>
+ *
+ * Redistribution and use in source and binary forms, with or without modification,
+ * are permitted provided that the following conditions are met:
+ *   1. Redistributions of source code must retain the above copyright notice,
+ *      this list of conditions and the following disclaimer.
+ *   2. Redistributions in binary form must reproduce the above copyright notice,
+ *      this list of conditions and the following disclaimer in the documentation
+ *      and/or other materials provided with the distribution.
+ *   3. Neither the name of STMicroelectronics nor the names of its contributors
+ *      may be used to endorse or promote products derived from this software
+ *      without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ ******************************************************************************
+ */
+
+/* Define to prevent from recursive inclusion --------------------------------*/
+#ifndef __DEV_I2C_H
+#define __DEV_I2C_H
+
+/* Includes ------------------------------------------------------------------*/
+#include "mbed.h"
+
+/* Classes -------------------------------------------------------------------*/
+/** Helper class DevI2C providing functions for multi-register I2C communication
+ *  common for a series of I2C devices
+ */
+class DevI2C : public I2C
+{
+ public:
+	/** Create a DevI2C Master interface, connected to the specified pins
+	 *
+	 *  @param sda I2C data line pin
+	 *  @param scl I2C clock line pin
+	 */
+ DevI2C(PinName sda, PinName scl) : I2C(sda, scl) {};
+
+	/**
+	 * @brief  Writes a buffer from the I2C peripheral device.
+	 * @param  pBuffer pointer to data to be written.
+	 * @param  DeviceAddr specifies the peripheral device slave address.
+	 * @param  RegisterAddr specifies the internal address register 
+	 *         where to start writing to (must be correctly masked).
+	 * @param  NumByteToWrite number of bytes to be written.
+	 * @retval 0 if ok, -1 if an I2C error has occured
+	 * @note   On some devices if NumByteToWrite is greater
+	 *         than one, the RegisterAddr must be masked correctly!
+	 */
+	int i2c_write(uint8_t* pBuffer, uint8_t DeviceAddr, uint8_t RegisterAddr, 
+		      uint16_t NumByteToWrite)
+	{
+		int ret;
+		uint8_t tmp[32];
+	
+		/* First, send device address. Then, send data and STOP condition */
+		tmp[0] = RegisterAddr;
+		memcpy(tmp+1, pBuffer, NumByteToWrite);
+
+		ret = write(DeviceAddr, (const char*)tmp, NumByteToWrite+1, 0);
+
+		if(ret) {
+			error("%s: dev = %d, reg = %d, num = %d\n",
+			      __func__, DeviceAddr, RegisterAddr, NumByteToWrite);
+			return -1;
+		}
+		return 0;
+	}
+
+	/**
+	 * @brief  Reads a buffer from the I2C peripheral device.
+	 * @param  pBuffer pointer to data to be read.
+	 * @param  DaviceAddr specifies the peripheral device slave address.
+	 * @param  RegisterAddr specifies the internal address register 
+	 *         where to start reading from (must be correctly masked).
+	 * @param  NumByteToRead number of bytes to be read.
+	 * @retval 0 if ok, -1 if an I2C error has occured
+	 * @note   On some devices if NumByteToWrite is greater
+	 *         than one, the RegisterAddr must be masked correctly!
+	 */
+	int i2c_read(uint8_t* pBuffer, uint8_t DeviceAddr, uint8_t RegisterAddr, 
+		     uint16_t NumByteToRead)
+	{
+		int ret;
+    
+		/* Send device address, with no STOP condition */
+		ret = write(DeviceAddr, (const char*)&RegisterAddr, 1, 1);
+		if(!ret) {
+			/* Read data, with STOP condition  */
+			ret = read(DeviceAddr, (char*)pBuffer, NumByteToRead, 0);
+		}
+    
+		if(ret) {
+			error("%s: dev = %d, reg = %d, num = %d\n",
+			      __func__, DeviceAddr, RegisterAddr, NumByteToRead);
+			return -1;
+		}
+		return 0;
+	}
+};
+
+#endif /* __DEV_I2C_H */