1 /*
2 * Author: Brendan Le Foll <brendan.le.foll@intel.com>
3 * Copyright (c) 2014 Intel Corporation.
4 *
5 * Code based on LSM303DLH sample by Jim Lindblom SparkFun Electronics
6 * and the CompensatedCompass.ino by Frankie Chu from SeedStudio
7 *
8 * Permission is hereby granted, free of charge, to any person obtaining
9 * a copy of this software and associated documentation files (the
10 * "Software"), to deal in the Software without restriction, including
11 * without limitation the rights to use, copy, modify, merge, publish,
12 * distribute, sublicense, and/or sell copies of the Software, and to
13 * permit persons to whom the Software is furnished to do so, subject to
14 * the following conditions:
15 *
16 * The above copyright notice and this permission notice shall be
17 * included in all copies or substantial portions of the Software.
18 *
19 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
20 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
21 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
22 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
23 * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
24 * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
25 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
26 */
27
28 #include <iostream>
29 #include <string>
30 #include <stdexcept>
31 #include <unistd.h>
32 #include <stdlib.h>
33
34 #include "lsm303.h"
35
36 using namespace upm;
37
LSM303(int bus,int addrMag,int addrAcc,int accScale)38 LSM303::LSM303(int bus, int addrMag, int addrAcc, int accScale) : m_i2c(bus)
39 {
40 m_addrMag = addrMag;
41 m_addrAcc = addrAcc;
42
43 // 0x27 is the 'normal' mode with X/Y/Z enable
44 setRegisterSafe(m_addrAcc, CTRL_REG1_A, 0x27);
45
46 // scale can be 2, 4 or 8
47 if (2 == accScale) {
48 setRegisterSafe(m_addrAcc, CTRL_REG4_A, 0x00);
49 } else if (4 == accScale) {
50 setRegisterSafe(m_addrAcc, CTRL_REG4_A, 0x10);
51 } else { // default; equivalent to 8g
52 setRegisterSafe(m_addrAcc, CTRL_REG4_A, 0x30);
53 }
54
55 // 0x10 = minimum datarate ~15Hz output rate
56 setRegisterSafe(m_addrMag, CRA_REG_M, 0x10);
57
58 // magnetic scale = +/-1.3
59 // Gaussmagnetic scale = +/-1.3Gauss (0x20)
60 // +-8.1Gauss (0xe0)
61 setRegisterSafe(m_addrMag, CRB_REG_M, 0xe0);
62
63 // 0x00 = continouous conversion mode
64 setRegisterSafe(m_addrMag, MR_REG_M, 0x00);
65 }
66
67 float
getHeading()68 LSM303::getHeading()
69 {
70 if (getCoordinates() != mraa::SUCCESS) {
71 return -1;
72 }
73
74 float heading = 180.0 * atan2(double(coor[Y]), double(coor[X]))/M_PI;
75
76 if (heading < 0.0)
77 heading += 360.0;
78
79 return heading;
80 }
81
82 int16_t*
getRawAccelData()83 LSM303::getRawAccelData()
84 {
85 return &accel[0];
86 }
87
88 int16_t*
getRawCoorData()89 LSM303::getRawCoorData()
90 {
91 return &coor[0];
92 }
93
94 int16_t
getAccelX()95 LSM303::getAccelX()
96 {
97 return accel[X];
98 }
99
100 int16_t
getAccelY()101 LSM303::getAccelY()
102 {
103 return accel[Y];
104 }
105
106 int16_t
getAccelZ()107 LSM303::getAccelZ()
108 {
109 return accel[Z];
110 }
111
112 mraa::Result
getCoordinates()113 LSM303::getCoordinates()
114 {
115 mraa::Result ret = mraa::SUCCESS;
116
117 memset(&buf[0], 0, sizeof(uint8_t)*6);
118 ret = m_i2c.address(m_addrMag);
119 ret = m_i2c.writeByte(OUT_X_H_M);
120 ret = m_i2c.address(m_addrMag);
121 int num = m_i2c.read(buf, 6);
122 if (num != 6) {
123 return ret;
124 }
125 // convert to coordinates
126 for (int i=0; i<3; i++) {
127 coor[i] = (int16_t(buf[2*i] << 8))
128 | int16_t(buf[(2*i)+1]);
129 }
130 // swap elements 1 and 2 to get things in natural XYZ order
131 int16_t t = coor[2];
132 coor[2] = coor[1];
133 coor[1] = t;
134 //printf("X=%x, Y=%x, Z=%x\n", coor[X], coor[Y], coor[Z]);
135
136 return ret;
137 }
138
139 int16_t
getCoorX()140 LSM303::getCoorX() {
141 return coor[X];
142 }
143
144 int16_t
getCoorY()145 LSM303::getCoorY() {
146 return coor[Y];
147 }
148
149 int16_t
getCoorZ()150 LSM303::getCoorZ() {
151 return coor[Z];
152 }
153
154 // helper function that writes a value to the acc and then reads
155 // FIX: shouldn't this be write-then-read?
156 int
readThenWrite(uint8_t reg)157 LSM303::readThenWrite(uint8_t reg)
158 {
159 m_i2c.address(m_addrAcc);
160 m_i2c.writeByte(reg);
161 m_i2c.address(m_addrAcc);
162 return (int) m_i2c.readByte();
163 }
164
165 mraa::Result
getAcceleration()166 LSM303::getAcceleration()
167 {
168 mraa::Result ret = mraa::SUCCESS;
169
170 accel[X] = (int16_t(readThenWrite(OUT_X_H_A)) << 8)
171 | int16_t(readThenWrite(OUT_X_L_A));
172 accel[Y] = (int16_t(readThenWrite(OUT_Y_H_A)) << 8)
173 | int16_t(readThenWrite(OUT_Y_L_A));
174 accel[Z] = (int16_t(readThenWrite(OUT_Z_H_A)) << 8)
175 | int16_t(readThenWrite(OUT_Z_L_A));
176 //printf("X=%x, Y=%x, Z=%x\n", accel[X], accel[Y], accel[Z]);
177
178 return ret;
179 }
180
181 // helper function that sets a register and then checks the set was succesful
182 mraa::Result
setRegisterSafe(uint8_t slave,uint8_t sregister,uint8_t data)183 LSM303::setRegisterSafe(uint8_t slave, uint8_t sregister, uint8_t data)
184 {
185 buf[0] = sregister;
186 buf[1] = data;
187
188 if (m_i2c.address(slave) != mraa::SUCCESS) {
189 throw std::invalid_argument(std::string(__FUNCTION__) +
190 ": mraa_i2c_address() failed");
191 return mraa::ERROR_INVALID_HANDLE;
192 }
193 if (m_i2c.write(buf, 2) != mraa::SUCCESS) {
194 throw std::invalid_argument(std::string(__FUNCTION__) +
195 ": mraa_i2c_write() failed");
196 return mraa::ERROR_INVALID_HANDLE;
197 }
198 uint8_t val = m_i2c.readReg(sregister);
199 if (val != data) {
200 throw std::invalid_argument(std::string(__FUNCTION__) +
201 ": failed to set register correctly");
202 return mraa::ERROR_UNSPECIFIED;
203 }
204 return mraa::SUCCESS;
205 }
206