Naresh Krish / Mbed OS itracker-mbed-os-example-lis3dh

Sample program on how to use the LIS3DH sensor on the RAKWireless iTracker module

LIS3DH/LIS3DH.cpp@0:cd96b05ace6e, 2018-02-12 (annotated)

Committer:
knaresh89
Date:
Mon Feb 12 05:05:29 2018 +0000
Revision:
0:cd96b05ace6e
Sample program on how to use the LIS3DH sensor on the RAKWireless iTracker module

Who changed what in which revision?

UserRevisionLine numberNew contents of line
knaresh89 0:cd96b05ace6e 1 /*
knaresh89 0:cd96b05ace6e 2 * mbed library program
knaresh89 0:cd96b05ace6e 3 * LIS3DH MEMS motion sensor: 3-axis "nano" accelerometer, made by STMicroelectronics
knaresh89 0:cd96b05ace6e 4 * http://www.st-japan.co.jp/web/jp/catalog/sense_power/FM89/SC444/PF250725
knaresh89 0:cd96b05ace6e 5 *
knaresh89 0:cd96b05ace6e 6 * Copyright (c) 2014,'15,'17 Kenji Arai / JH1PJL
knaresh89 0:cd96b05ace6e 7 * http://www.page.sannet.ne.jp/kenjia/index.html
knaresh89 0:cd96b05ace6e 8 * http://mbed.org/users/kenjiArai/
knaresh89 0:cd96b05ace6e 9 * Created: July 14th, 2014
knaresh89 0:cd96b05ace6e 10 * Revised: August 23rd, 2017
knaresh89 0:cd96b05ace6e 11 */
knaresh89 0:cd96b05ace6e 12
knaresh89 0:cd96b05ace6e 13 #include "LIS3DH.h"
knaresh89 0:cd96b05ace6e 14 #include "SEGGER_RTT.h"
knaresh89 0:cd96b05ace6e 15
knaresh89 0:cd96b05ace6e 16 LIS3DH::LIS3DH (PinName p_sda, PinName p_scl,
knaresh89 0:cd96b05ace6e 17 uint8_t addr, uint8_t data_rate, uint8_t fullscale)
knaresh89 0:cd96b05ace6e 18 : _i2c_p(new I2C(p_sda, p_scl)), _i2c(*_i2c_p)
knaresh89 0:cd96b05ace6e 19 {
knaresh89 0:cd96b05ace6e 20 _i2c.frequency(400000);
knaresh89 0:cd96b05ace6e 21 initialize (addr, data_rate, fullscale);
knaresh89 0:cd96b05ace6e 22 }
knaresh89 0:cd96b05ace6e 23
knaresh89 0:cd96b05ace6e 24 LIS3DH::LIS3DH (PinName p_sda, PinName p_scl, uint8_t addr)
knaresh89 0:cd96b05ace6e 25 : _i2c_p(new I2C(p_sda, p_scl)), _i2c(*_i2c_p)
knaresh89 0:cd96b05ace6e 26 {
knaresh89 0:cd96b05ace6e 27 _i2c.frequency(400000);
knaresh89 0:cd96b05ace6e 28 initialize (addr, LIS3DH_DR_NR_LP_50HZ, LIS3DH_FS_8G);
knaresh89 0:cd96b05ace6e 29 }
knaresh89 0:cd96b05ace6e 30
knaresh89 0:cd96b05ace6e 31 LIS3DH::LIS3DH (I2C& p_i2c,
knaresh89 0:cd96b05ace6e 32 uint8_t addr, uint8_t data_rate, uint8_t fullscale)
knaresh89 0:cd96b05ace6e 33 : _i2c(p_i2c)
knaresh89 0:cd96b05ace6e 34 {
knaresh89 0:cd96b05ace6e 35 _i2c.frequency(400000);
knaresh89 0:cd96b05ace6e 36 initialize (addr, data_rate, fullscale);
knaresh89 0:cd96b05ace6e 37 }
knaresh89 0:cd96b05ace6e 38
knaresh89 0:cd96b05ace6e 39 LIS3DH::LIS3DH (I2C& p_i2c, uint8_t addr)
knaresh89 0:cd96b05ace6e 40 : _i2c(p_i2c)
knaresh89 0:cd96b05ace6e 41 {
knaresh89 0:cd96b05ace6e 42 _i2c.frequency(400000);
knaresh89 0:cd96b05ace6e 43 initialize (addr, LIS3DH_DR_NR_LP_50HZ, LIS3DH_FS_8G);
knaresh89 0:cd96b05ace6e 44 }
knaresh89 0:cd96b05ace6e 45
knaresh89 0:cd96b05ace6e 46 void LIS3DH::initialize (uint8_t addr, uint8_t data_rate, uint8_t fullscale)
knaresh89 0:cd96b05ace6e 47 {
knaresh89 0:cd96b05ace6e 48 // Check acc is available of not
knaresh89 0:cd96b05ace6e 49 acc_addr = addr;
knaresh89 0:cd96b05ace6e 50 dt[0] = LIS3DH_WHO_AM_I;
knaresh89 0:cd96b05ace6e 51 _i2c.write(acc_addr, dt, 1, true);
knaresh89 0:cd96b05ace6e 52 _i2c.read(acc_addr, dt, 1, false);
knaresh89 0:cd96b05ace6e 53 if (dt[0] == I_AM_LIS3DH) {
knaresh89 0:cd96b05ace6e 54 acc_ready = 1;
knaresh89 0:cd96b05ace6e 55 } else {
knaresh89 0:cd96b05ace6e 56 acc_ready = 0;
knaresh89 0:cd96b05ace6e 57 return; // acc chip is NOT on I2C line then terminate
knaresh89 0:cd96b05ace6e 58 }
knaresh89 0:cd96b05ace6e 59 // Reg.1
knaresh89 0:cd96b05ace6e 60 dt[0] = LIS3DH_CTRL_REG1;
knaresh89 0:cd96b05ace6e 61 dt[1] = 0x07;
knaresh89 0:cd96b05ace6e 62 dt[1] |= data_rate << 4;
knaresh89 0:cd96b05ace6e 63 _i2c.write(acc_addr, dt, 2, false);
knaresh89 0:cd96b05ace6e 64 // Reg.4
knaresh89 0:cd96b05ace6e 65 dt[0] = LIS3DH_CTRL_REG4;
knaresh89 0:cd96b05ace6e 66 dt[1] = 0x08; // High resolution
knaresh89 0:cd96b05ace6e 67 dt[1] |= fullscale << 4;
knaresh89 0:cd96b05ace6e 68 _i2c.write(acc_addr, dt, 2, false);
knaresh89 0:cd96b05ace6e 69 switch (fullscale) {
knaresh89 0:cd96b05ace6e 70 case LIS3DH_FS_2G:
knaresh89 0:cd96b05ace6e 71 fs_factor = LIS3DH_SENSITIVITY_2G;
knaresh89 0:cd96b05ace6e 72 break;
knaresh89 0:cd96b05ace6e 73 case LIS3DH_FS_4G:
knaresh89 0:cd96b05ace6e 74 fs_factor = LIS3DH_SENSITIVITY_4G;
knaresh89 0:cd96b05ace6e 75 break;
knaresh89 0:cd96b05ace6e 76 case LIS3DH_FS_8G:
knaresh89 0:cd96b05ace6e 77 fs_factor = LIS3DH_SENSITIVITY_8G;
knaresh89 0:cd96b05ace6e 78 break;
knaresh89 0:cd96b05ace6e 79 case LIS3DH_FS_16G:
knaresh89 0:cd96b05ace6e 80 fs_factor = LIS3DH_SENSITIVITY_16G;
knaresh89 0:cd96b05ace6e 81 break;
knaresh89 0:cd96b05ace6e 82 default:
knaresh89 0:cd96b05ace6e 83 ;
knaresh89 0:cd96b05ace6e 84 }
knaresh89 0:cd96b05ace6e 85 }
knaresh89 0:cd96b05ace6e 86
knaresh89 0:cd96b05ace6e 87 void LIS3DH::read_reg_data(char *data)
knaresh89 0:cd96b05ace6e 88 {
knaresh89 0:cd96b05ace6e 89 // X,Y & Z
knaresh89 0:cd96b05ace6e 90 // manual said that
knaresh89 0:cd96b05ace6e 91 // In order to read multiple bytes, it is necessary to assert the most significant bit
knaresh89 0:cd96b05ace6e 92 // of the subaddress field.
knaresh89 0:cd96b05ace6e 93 // In other words, SUB(7) must be equal to ‘1’ while SUB(6-0) represents the address
knaresh89 0:cd96b05ace6e 94 // of the first register to be read.
knaresh89 0:cd96b05ace6e 95 dt[0] = LIS3DH_OUT_X_L | 0x80;
knaresh89 0:cd96b05ace6e 96 _i2c.write(acc_addr, dt, 1, true);
knaresh89 0:cd96b05ace6e 97 _i2c.read(acc_addr, data, 6, false);
knaresh89 0:cd96b05ace6e 98 }
knaresh89 0:cd96b05ace6e 99
knaresh89 0:cd96b05ace6e 100 void LIS3DH::read_mg_data(float *dt_usr)
knaresh89 0:cd96b05ace6e 101 {
knaresh89 0:cd96b05ace6e 102 char data[6];
knaresh89 0:cd96b05ace6e 103
knaresh89 0:cd96b05ace6e 104 if (acc_ready == 0) {
knaresh89 0:cd96b05ace6e 105 dt_usr[0] = 0;
knaresh89 0:cd96b05ace6e 106 dt_usr[1] = 0;
knaresh89 0:cd96b05ace6e 107 dt_usr[2] = 0;
knaresh89 0:cd96b05ace6e 108 return;
knaresh89 0:cd96b05ace6e 109 }
knaresh89 0:cd96b05ace6e 110 read_reg_data(data);
knaresh89 0:cd96b05ace6e 111 // change data type
knaresh89 0:cd96b05ace6e 112 #if OLD_REV // Fixed bugs -> (1) unit is not mg but g (2) shift right 4bit = /16
knaresh89 0:cd96b05ace6e 113 dt_usr[0] = float(short((data[1] << 8) | data[0])) * fs_factor / 15;
knaresh89 0:cd96b05ace6e 114 dt_usr[1] = float(short((data[3] << 8) | data[2])) * fs_factor / 15;
knaresh89 0:cd96b05ace6e 115 dt_usr[2] = float(short((data[5] << 8) | data[4])) * fs_factor / 15;
knaresh89 0:cd96b05ace6e 116 #else
knaresh89 0:cd96b05ace6e 117 dt_usr[0] = float(short((data[1] << 8) | data[0]) >> 4) * fs_factor;
knaresh89 0:cd96b05ace6e 118 dt_usr[1] = float(short((data[3] << 8) | data[2]) >> 4) * fs_factor;
knaresh89 0:cd96b05ace6e 119 dt_usr[2] = float(short((data[5] << 8) | data[4]) >> 4) * fs_factor;
knaresh89 0:cd96b05ace6e 120 #endif
knaresh89 0:cd96b05ace6e 121 SEGGER_RTT_printf(0, "x val : %f", dt_usr[0]);
knaresh89 0:cd96b05ace6e 122
knaresh89 0:cd96b05ace6e 123 }
knaresh89 0:cd96b05ace6e 124
knaresh89 0:cd96b05ace6e 125 void LIS3DH::read_data(float *dt_usr)
knaresh89 0:cd96b05ace6e 126 {
knaresh89 0:cd96b05ace6e 127 char data[6];
knaresh89 0:cd96b05ace6e 128
knaresh89 0:cd96b05ace6e 129 if (acc_ready == 0) {
knaresh89 0:cd96b05ace6e 130 dt_usr[0] = 0;
knaresh89 0:cd96b05ace6e 131 dt_usr[1] = 0;
knaresh89 0:cd96b05ace6e 132 dt_usr[2] = 0;
knaresh89 0:cd96b05ace6e 133 return;
knaresh89 0:cd96b05ace6e 134 }
knaresh89 0:cd96b05ace6e 135 read_reg_data(data);
knaresh89 0:cd96b05ace6e 136 // change data type
knaresh89 0:cd96b05ace6e 137 #if OLD_REV // Fixed bugs -> shift right 4bit = /16 (not /15)
knaresh89 0:cd96b05ace6e 138 dt_usr[0] = float(short((data[1] << 8) | data[0])) * fs_factor / 15 * GRAVITY;
knaresh89 0:cd96b05ace6e 139 dt_usr[1] = float(short((data[3] << 8) | data[2])) * fs_factor / 15 * GRAVITY;
knaresh89 0:cd96b05ace6e 140 dt_usr[2] = float(short((data[5] << 8) | data[4])) * fs_factor / 15 * GRAVITY;
knaresh89 0:cd96b05ace6e 141 #else
knaresh89 0:cd96b05ace6e 142 dt_usr[0] = float(short((data[1] << 8) | data[0]) >> 4) * fs_factor * GRAVITY;
knaresh89 0:cd96b05ace6e 143 dt_usr[1] = float(short((data[3] << 8) | data[2]) >> 4) * fs_factor * GRAVITY;
knaresh89 0:cd96b05ace6e 144 dt_usr[2] = float(short((data[5] << 8) | data[4]) >> 4) * fs_factor * GRAVITY;
knaresh89 0:cd96b05ace6e 145 #endif
knaresh89 0:cd96b05ace6e 146 SEGGER_RTT_printf(0, "x val : %d \n", (short((data[1] << 8) | data[0]) >> 4));
knaresh89 0:cd96b05ace6e 147 }
knaresh89 0:cd96b05ace6e 148
knaresh89 0:cd96b05ace6e 149 uint8_t LIS3DH::read_id()
knaresh89 0:cd96b05ace6e 150 {
knaresh89 0:cd96b05ace6e 151 dt[0] = LIS3DH_WHO_AM_I;
knaresh89 0:cd96b05ace6e 152 _i2c.write(acc_addr, dt, 1, true);
knaresh89 0:cd96b05ace6e 153 _i2c.read(acc_addr, dt, 1, false);
knaresh89 0:cd96b05ace6e 154 return (uint8_t)dt[0];
knaresh89 0:cd96b05ace6e 155 }
knaresh89 0:cd96b05ace6e 156
knaresh89 0:cd96b05ace6e 157 uint8_t LIS3DH::data_ready()
knaresh89 0:cd96b05ace6e 158 {
knaresh89 0:cd96b05ace6e 159 if (acc_ready == 1) {
knaresh89 0:cd96b05ace6e 160 dt[0] = LIS3DH_STATUS_REG_AUX;
knaresh89 0:cd96b05ace6e 161 _i2c.write(acc_addr, dt, 1, true);
knaresh89 0:cd96b05ace6e 162 _i2c.read(acc_addr, dt, 1, false);
knaresh89 0:cd96b05ace6e 163 if (!(dt[0] & 0x01)) {
knaresh89 0:cd96b05ace6e 164 return 0;
knaresh89 0:cd96b05ace6e 165 }
knaresh89 0:cd96b05ace6e 166 }
knaresh89 0:cd96b05ace6e 167 return 1;
knaresh89 0:cd96b05ace6e 168 }
knaresh89 0:cd96b05ace6e 169
knaresh89 0:cd96b05ace6e 170 void LIS3DH::frequency(int hz)
knaresh89 0:cd96b05ace6e 171 {
knaresh89 0:cd96b05ace6e 172 _i2c.frequency(hz);
knaresh89 0:cd96b05ace6e 173 }
knaresh89 0:cd96b05ace6e 174
knaresh89 0:cd96b05ace6e 175 uint8_t LIS3DH::read_reg(uint8_t addr)
knaresh89 0:cd96b05ace6e 176 {
knaresh89 0:cd96b05ace6e 177 if (acc_ready == 1) {
knaresh89 0:cd96b05ace6e 178 dt[0] = addr;
knaresh89 0:cd96b05ace6e 179 _i2c.write(acc_addr, dt, 1, true);
knaresh89 0:cd96b05ace6e 180 _i2c.read(acc_addr, dt, 1, false);
knaresh89 0:cd96b05ace6e 181 } else {
knaresh89 0:cd96b05ace6e 182 dt[0] = 0xff;
knaresh89 0:cd96b05ace6e 183 }
knaresh89 0:cd96b05ace6e 184 return (uint8_t)dt[0];
knaresh89 0:cd96b05ace6e 185 }
knaresh89 0:cd96b05ace6e 186
knaresh89 0:cd96b05ace6e 187 void LIS3DH::write_reg(uint8_t addr, uint8_t data)
knaresh89 0:cd96b05ace6e 188 {
knaresh89 0:cd96b05ace6e 189 if (acc_ready == 1) {
knaresh89 0:cd96b05ace6e 190 dt[0] = addr;
knaresh89 0:cd96b05ace6e 191 dt[1] = data;
knaresh89 0:cd96b05ace6e 192 _i2c.write(acc_addr, dt, 2, false);
knaresh89 0:cd96b05ace6e 193 }
knaresh89 0:cd96b05ace6e 194 }
knaresh89 0:cd96b05ace6e 195
knaresh89 0:cd96b05ace6e 196