Marcelo Barros / sens_itf

Generic communication interface between the wireless board (mote) and the sensor board. Any kind of sensor board can be connected to the mote using this specification given it provides a SPI peripheral, one input pin with interrupt capability and one digital output. The sensor board must implement a special register set from which all required information can be retrieved. Protocol: http://is.gd/wuQorh Github: http://is.gd/ySj1L9

Dependencies:   mbed-src

MMA8451Q/MMA8451Q.cpp@1:acdf490d94a7, 2014-04-08 (annotated)

Committer:
marcelobarrosalmeida
Date:
Tue Apr 08 16:34:20 2014 +0000
Revision:
1:acdf490d94a7
Adding accel to sensor list

Who changed what in which revision?

UserRevisionLine numberNew contents of line
marcelobarrosalmeida 1:acdf490d94a7 1 /* Copyright (c) 2010-2011 mbed.org, MIT License
marcelobarrosalmeida 1:acdf490d94a7 2 *
marcelobarrosalmeida 1:acdf490d94a7 3 * Permission is hereby granted, free of charge, to any person obtaining a copy of this software
marcelobarrosalmeida 1:acdf490d94a7 4 * and associated documentation files (the "Software"), to deal in the Software without
marcelobarrosalmeida 1:acdf490d94a7 5 * restriction, including without limitation the rights to use, copy, modify, merge, publish,
marcelobarrosalmeida 1:acdf490d94a7 6 * distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the
marcelobarrosalmeida 1:acdf490d94a7 7 * Software is furnished to do so, subject to the following conditions:
marcelobarrosalmeida 1:acdf490d94a7 8 *
marcelobarrosalmeida 1:acdf490d94a7 9 * The above copyright notice and this permission notice shall be included in all copies or
marcelobarrosalmeida 1:acdf490d94a7 10 * substantial portions of the Software.
marcelobarrosalmeida 1:acdf490d94a7 11 *
marcelobarrosalmeida 1:acdf490d94a7 12 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING
marcelobarrosalmeida 1:acdf490d94a7 13 * BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
marcelobarrosalmeida 1:acdf490d94a7 14 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
marcelobarrosalmeida 1:acdf490d94a7 15 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
marcelobarrosalmeida 1:acdf490d94a7 16 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
marcelobarrosalmeida 1:acdf490d94a7 17 */
marcelobarrosalmeida 1:acdf490d94a7 18
marcelobarrosalmeida 1:acdf490d94a7 19 #include "MMA8451Q.h"
marcelobarrosalmeida 1:acdf490d94a7 20
marcelobarrosalmeida 1:acdf490d94a7 21 #define REG_WHO_AM_I 0x0D
marcelobarrosalmeida 1:acdf490d94a7 22 #define REG_CTRL_REG_1 0x2A
marcelobarrosalmeida 1:acdf490d94a7 23 #define REG_OUT_X_MSB 0x01
marcelobarrosalmeida 1:acdf490d94a7 24 #define REG_OUT_Y_MSB 0x03
marcelobarrosalmeida 1:acdf490d94a7 25 #define REG_OUT_Z_MSB 0x05
marcelobarrosalmeida 1:acdf490d94a7 26
marcelobarrosalmeida 1:acdf490d94a7 27 #define UINT14_MAX 16383
marcelobarrosalmeida 1:acdf490d94a7 28
marcelobarrosalmeida 1:acdf490d94a7 29 MMA8451Q::MMA8451Q(PinName sda, PinName scl, int addr) : m_i2c(sda, scl), m_addr(addr) {
marcelobarrosalmeida 1:acdf490d94a7 30 // activate the peripheral
marcelobarrosalmeida 1:acdf490d94a7 31 uint8_t data[2] = {REG_CTRL_REG_1, 0x01};
marcelobarrosalmeida 1:acdf490d94a7 32 writeRegs(data, 2);
marcelobarrosalmeida 1:acdf490d94a7 33 }
marcelobarrosalmeida 1:acdf490d94a7 34
marcelobarrosalmeida 1:acdf490d94a7 35 MMA8451Q::~MMA8451Q() { }
marcelobarrosalmeida 1:acdf490d94a7 36
marcelobarrosalmeida 1:acdf490d94a7 37 uint8_t MMA8451Q::getWhoAmI() {
marcelobarrosalmeida 1:acdf490d94a7 38 uint8_t who_am_i = 0;
marcelobarrosalmeida 1:acdf490d94a7 39 readRegs(REG_WHO_AM_I, &who_am_i, 1);
marcelobarrosalmeida 1:acdf490d94a7 40 return who_am_i;
marcelobarrosalmeida 1:acdf490d94a7 41 }
marcelobarrosalmeida 1:acdf490d94a7 42
marcelobarrosalmeida 1:acdf490d94a7 43 float MMA8451Q::getAccX() {
marcelobarrosalmeida 1:acdf490d94a7 44 return (float(getAccAxis(REG_OUT_X_MSB))/4096.0);
marcelobarrosalmeida 1:acdf490d94a7 45 }
marcelobarrosalmeida 1:acdf490d94a7 46
marcelobarrosalmeida 1:acdf490d94a7 47 float MMA8451Q::getAccY() {
marcelobarrosalmeida 1:acdf490d94a7 48 return (float(getAccAxis(REG_OUT_Y_MSB))/4096.0);
marcelobarrosalmeida 1:acdf490d94a7 49 }
marcelobarrosalmeida 1:acdf490d94a7 50
marcelobarrosalmeida 1:acdf490d94a7 51 float MMA8451Q::getAccZ() {
marcelobarrosalmeida 1:acdf490d94a7 52 return (float(getAccAxis(REG_OUT_Z_MSB))/4096.0);
marcelobarrosalmeida 1:acdf490d94a7 53 }
marcelobarrosalmeida 1:acdf490d94a7 54
marcelobarrosalmeida 1:acdf490d94a7 55 void MMA8451Q::getAccAllAxis(float * res) {
marcelobarrosalmeida 1:acdf490d94a7 56 res[0] = getAccX();
marcelobarrosalmeida 1:acdf490d94a7 57 res[1] = getAccY();
marcelobarrosalmeida 1:acdf490d94a7 58 res[2] = getAccZ();
marcelobarrosalmeida 1:acdf490d94a7 59 }
marcelobarrosalmeida 1:acdf490d94a7 60
marcelobarrosalmeida 1:acdf490d94a7 61 int16_t MMA8451Q::getAccAxis(uint8_t addr) {
marcelobarrosalmeida 1:acdf490d94a7 62 int16_t acc;
marcelobarrosalmeida 1:acdf490d94a7 63 uint8_t res[2];
marcelobarrosalmeida 1:acdf490d94a7 64 readRegs(addr, res, 2);
marcelobarrosalmeida 1:acdf490d94a7 65
marcelobarrosalmeida 1:acdf490d94a7 66 acc = (res[0] << 6) | (res[1] >> 2);
marcelobarrosalmeida 1:acdf490d94a7 67 if (acc > UINT14_MAX/2)
marcelobarrosalmeida 1:acdf490d94a7 68 acc -= UINT14_MAX;
marcelobarrosalmeida 1:acdf490d94a7 69
marcelobarrosalmeida 1:acdf490d94a7 70 return acc;
marcelobarrosalmeida 1:acdf490d94a7 71 }
marcelobarrosalmeida 1:acdf490d94a7 72
marcelobarrosalmeida 1:acdf490d94a7 73 void MMA8451Q::readRegs(int addr, uint8_t * data, int len) {
marcelobarrosalmeida 1:acdf490d94a7 74 char t[1] = {addr};
marcelobarrosalmeida 1:acdf490d94a7 75 m_i2c.write(m_addr, t, 1, true);
marcelobarrosalmeida 1:acdf490d94a7 76 m_i2c.read(m_addr, (char *)data, len);
marcelobarrosalmeida 1:acdf490d94a7 77 }
marcelobarrosalmeida 1:acdf490d94a7 78
marcelobarrosalmeida 1:acdf490d94a7 79 void MMA8451Q::writeRegs(uint8_t * data, int len) {
marcelobarrosalmeida 1:acdf490d94a7 80 m_i2c.write(m_addr, (char *)data, len);
marcelobarrosalmeida 1:acdf490d94a7 81 }