MPL3115A2.cpp

00001 /* Copyright (c) 2010-2011 mbed.org, MIT License
00002 *
00003 * Permission is hereby granted, free of charge, to any person obtaining a copy of this software
00004 * and associated documentation files (the "Software"), to deal in the Software without
00005 * restriction, including without limitation the rights to use, copy, modify, merge, publish,
00006 * distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the
00007 * Software is furnished to do so, subject to the following conditions:
00008 *
00009 * The above copyright notice and this permission notice shall be included in all copies or
00010 * substantial portions of the Software.
00011 *
00012 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING
00013 * BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
00014 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
00015 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
00016 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
00017 */
00018  
00019 #include "MPL3115A2.h"
00020 
00021 #define REG_WHO_AM_I        0x0C        // return 0xC4 by default
00022 #define REG_STATUS          0x00
00023 #define REG_CTRL_REG_1      0x26
00024 #define REG_CTRL_REG_3      0x28
00025 #define REG_CTRL_REG_4      0x29
00026 #define REG_CTRL_REG_5      0x2A
00027 #define REG_PRESSURE_MSB    0x01        // 3 byte pressure data
00028 #define REG_ALTIMETER_MSB   0x01        // 3 byte altimeter data
00029 #define REG_TEMP_MSB        0x04        // 2 byte temperature data
00030 #define REG_PT_DATA_CFG     0x13
00031 #define REG_P_TGT_MSB       0x16
00032 #define REG_P_WND_MSB       0x19
00033 
00034 // Status flag for data ready.
00035 #define PTDR_STATUS       0x03        // Pressure Altitude and Temperature ready
00036 #define PDR_STATUS        0x02        // Pressure and Altitude data ready
00037 #define TDR_STATUS        0x01        // Temperature data ready
00038 
00039 MPL3115A2::MPL3115A2(PinName sda, PinName scl, int addr) : m_i2c(sda, scl), m_addr(addr) {
00040     unsigned char data[2] = {REG_CTRL_REG_1, 0xB8};
00041     m_i2c.frequency(375000);
00042     writeRegs(data, 2);
00043     data[0] = REG_PT_DATA_CFG;
00044     data[1] = 0x07;
00045     writeRegs(data, 2);
00046     data[0] = REG_CTRL_REG_1;
00047     data[1] = 0xB9;
00048     writeRegs(data, 2);
00049 }
00050 
00051 uint8_t MPL3115A2::isDataAvailable( void)
00052 {
00053     unsigned char status;
00054     readRegs( REG_STATUS, &status, 1);
00055     return ((status>>1) & 0x07);
00056     
00057 }
00058 
00059 uint8_t MPL3115A2::getAltimeterRaw( unsigned char *dt)
00060 {
00061     if ( isDataAvailable() & PDR_STATUS)
00062     {
00063         readRegs( REG_ALTIMETER_MSB, &dt[0], 2);
00064         return 1;    
00065     }
00066     else
00067         return 0;
00068 }
00069 
00070 uint8_t MPL3115A2::getTemperatureRaw( unsigned char *dt)
00071 {
00072     if ( isDataAvailable() & TDR_STATUS)
00073     {
00074         readRegs( REG_TEMP_MSB, &dt[0], 1);
00075         return 1;
00076     }
00077     else
00078         return 0;
00079 }
00080 
00081 void MPL3115A2::readRegs(int addr, uint8_t * data, int len) {
00082     char t[1] = {addr};
00083     m_i2c.write(m_addr, t, 1, true);
00084     m_i2c.read(m_addr, (char *)data, len);
00085 }
00086 
00087 void MPL3115A2::writeRegs(uint8_t * data, int len) {
00088     m_i2c.write(m_addr, (char *)data, len);
00089 }