LPS25H.cpp

00001 /*
00002  * mbed library program
00003  *  LPS25H MEMS pressure sensor: 260-1260 hPa absolute digital output barometer
00004  *   made by STMicroelectronics
00005  *   http://www.st-japan.co.jp/web/catalog/sense_power/FM89/SC1316/PF255230
00006  *
00007  * Copyright (c) 2015,'17 Kenji Arai / JH1PJL
00008  *  http://www.page.sannet.ne.jp/kenjia/index.html
00009  *  http://mbed.org/users/kenjiArai/
00010  *      Created: Feburary  21st, 2015
00011  *      Revised: August    21st, 2017
00012  */
00013 
00014 #include "LPS25H.h"
00015 
00016 LPS25H::LPS25H (PinName p_sda, PinName p_scl, uint8_t addr) :
00017  _i2c_p(new I2C(p_sda, p_scl)), _i2c(*_i2c_p)
00018 {
00019     LPS25H_addr = addr;
00020     LPS25H_mode = FIFO_HW_FILTER;
00021     init();
00022 }
00023 
00024 LPS25H::LPS25H (PinName p_sda, PinName p_scl, uint8_t addr, uint8_t mode) :
00025  _i2c_p(new I2C(p_sda, p_scl)), _i2c(*_i2c_p)
00026 {
00027     LPS25H_addr = addr;
00028     LPS25H_mode = mode;
00029     init();
00030 }
00031 
00032 LPS25H::LPS25H (I2C& p_i2c, uint8_t addr) : _i2c(p_i2c)
00033 {
00034     LPS25H_addr = addr;
00035     LPS25H_mode = FIFO_HW_FILTER;
00036     init();
00037 }
00038 
00039 LPS25H::LPS25H (I2C& p_i2c, uint8_t addr, uint8_t mode) : _i2c(p_i2c)
00040 {
00041     LPS25H_addr = addr;
00042     LPS25H_mode = mode;
00043     init();
00044 }
00045 
00046 /////////////// Initialize ////////////////////////////////
00047 void LPS25H::init(void)
00048 {
00049     _i2c.frequency(100000);
00050     // Check acc is available of not
00051     dt[0] = LPS25H_WHO_AM_I;
00052     _i2c.write(LPS25H_addr, dt, 1, true);
00053     _i2c.read(LPS25H_addr, dt, 1, false);
00054     if (dt[0] == I_AM_LPS25H) {
00055         LPS25H_id = I_AM_LPS25H;
00056         LPS25H_ready = 1;
00057     } else {
00058         LPS25H_id = 0;
00059         LPS25H_ready = 0;
00060         return;     // acc chip is NOT on I2C line then terminate
00061     }
00062     if (LPS25H_mode == FIFO_HW_FILTER){
00063         // Hardware digital filter
00064         // AN4450 April 2014 Rev1 P20/26,
00065         // Filter enabling and suggested configuration
00066         dt[0] = LPS25H_RES_CONF;
00067         dt[1] = 0x05;
00068         _i2c.write(LPS25H_addr, dt, 2, false);
00069         dt[0] = LPS25H_FIFO_CTRL;
00070         dt[1] = 0xdf;
00071         _i2c.write(LPS25H_addr, dt, 2, false);
00072         dt[0] = LPS25H_CTRL_REG2;
00073         dt[1] = 0x40;
00074         _i2c.write(LPS25H_addr, dt, 2, false);
00075         dt[0] = LPS25H_CTRL_REG1;
00076         dt[1] = 0x90;
00077         _i2c.write(LPS25H_addr, dt, 2, false);
00078     } else {
00079         dt[0] = LPS25H_CTRL_REG2;
00080         dt[1] = 0x0;
00081         _i2c.write(LPS25H_addr, dt, 2, false);
00082         dt[0] = LPS25H_CTRL_REG1;
00083         dt[1] = CR_STD_SET;
00084         _i2c.write(LPS25H_addr, dt, 2, false);
00085     }
00086 }
00087 
00088 /////////////// Start conv. and gwt all data //////////////
00089 void LPS25H::get(void)
00090 {
00091     if (LPS25H_ready == 0) {
00092         press = 0;
00093         temp = 0;
00094         return;
00095     }
00096     dt[0] = LPS25H_PRESS_POUT_XL | 0x80;
00097     _i2c.write(LPS25H_addr, dt, 1, true);
00098     _i2c.read(LPS25H_addr, dt, 3, false);
00099     press = dt[2] << 16 | dt[1] << 8 | dt[0];
00100     dt[0] = LPS25H_TEMP_OUT_L | 0x80;
00101     _i2c.write(LPS25H_addr, dt, 1, true);
00102     _i2c.read(LPS25H_addr, dt, 2, false);
00103     temp = dt[1] << 8 | dt[0];
00104 }
00105 
00106 /////////////// Read data from sensor /////////////////////
00107 float LPS25H::pressure()
00108 {
00109     return (float)press / 4096;
00110 }
00111 
00112 /////////////// Read data from sensor /////////////////////
00113 float LPS25H::temperature()
00114 {
00115     return (float)temp / 480  + 42.5;
00116 }
00117 
00118 /////////////// ID ////////////////////////////////////////
00119 uint8_t LPS25H::read_id()
00120 {
00121     dt[0] = LPS25H_WHO_AM_I;
00122     _i2c.write(LPS25H_addr, dt, 1, true);
00123     _i2c.read(LPS25H_addr, dt, 1, false);
00124     return (uint8_t)dt[0];
00125 }
00126 
00127 /////////////// I2C Freq. /////////////////////////////////
00128 void LPS25H::frequency(int hz)
00129 {
00130     _i2c.frequency(hz);
00131 }
00132 
00133 /////////////// General purpose R/W ///////////////////////
00134 uint8_t LPS25H::read_reg(uint8_t addr)
00135 {
00136     if (LPS25H_ready == 1) {
00137         dt[0] = addr;
00138         _i2c.write(LPS25H_addr, dt, 1, true);
00139         _i2c.read(LPS25H_addr, dt, 1, false);
00140     } else {
00141         dt[0] = 0xff;
00142     }
00143     return (uint8_t)dt[0];
00144 }
00145 
00146 void LPS25H::write_reg(uint8_t addr, uint8_t data)
00147 {
00148     if (LPS25H_ready == 1) {
00149         dt[0] = addr;
00150         dt[1] = data;
00151         _i2c.write(LPS25H_addr, dt, 2, false);
00152     }
00153 }