S5_mbed / MMA8452

library mma8452

Dependents:   APP3_Capteur_V2

Fork of MMA8452 by Ashley Mills

MMA8452.cpp@6:f6bde04bf8be, 2013-10-17 (annotated)

Committer:
ashleymills
Date:
Thu Oct 17 09:41:35 2013 +0000
Revision:
6:f6bde04bf8be
Parent:
5:b3d0abd97e55
Child:
8:89272163f395
Cleaning some things.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
nherriot 0:bcf2aa85d7f9 1 // Author: Nicholas Herriot
nherriot 0:bcf2aa85d7f9 2 /* Copyright (c) 2013 Vodafone, MIT License
nherriot 0:bcf2aa85d7f9 3 *
nherriot 0:bcf2aa85d7f9 4 * Permission is hereby granted, free of charge, to any person obtaining a copy of this software
nherriot 0:bcf2aa85d7f9 5 * and associated documentation files (the "Software"), to deal in the Software without restriction,
nherriot 0:bcf2aa85d7f9 6 * including without limitation the rights to use, copy, modify, merge, publish, distribute,
nherriot 0:bcf2aa85d7f9 7 * sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is
nherriot 0:bcf2aa85d7f9 8 * furnished to do so, subject to the following conditions:
nherriot 0:bcf2aa85d7f9 9 *
nherriot 0:bcf2aa85d7f9 10 * The above copyright notice and this permission notice shall be included in all copies or
nherriot 0:bcf2aa85d7f9 11 * substantial portions of the Software.
nherriot 0:bcf2aa85d7f9 12 *
nherriot 0:bcf2aa85d7f9 13 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING
nherriot 0:bcf2aa85d7f9 14 * BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
nherriot 0:bcf2aa85d7f9 15 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
nherriot 0:bcf2aa85d7f9 16 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
nherriot 0:bcf2aa85d7f9 17 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
nherriot 0:bcf2aa85d7f9 18 */
nherriot 0:bcf2aa85d7f9 19
nherriot 0:bcf2aa85d7f9 20 # include "MMA8452.h"
nherriot 0:bcf2aa85d7f9 21
nherriot 0:bcf2aa85d7f9 22 // Connect module at I2C address using I2C port pins sda and scl
nherriot 1:ef026bf28798 23 Accelerometer_MMA8452::Accelerometer_MMA8452(PinName sda, PinName scl,int frequency) : m_i2c(sda, scl) , m_frequency(frequency)
nherriot 0:bcf2aa85d7f9 24 {
nherriot 0:bcf2aa85d7f9 25 //m_i2c.frequency(m_frequency);
ashleymills 6:f6bde04bf8be 26
ashleymills 6:f6bde04bf8be 27 // setup read and write addresses to avoid duplication
ashleymills 6:f6bde04bf8be 28 _readAddress = (MMA8452_ADDRESS<<1) | 0x01;
ashleymills 6:f6bde04bf8be 29 _writeAddress = (MMA8452_ADDRESS<<1) & 0xFE;
nherriot 0:bcf2aa85d7f9 30 }
nherriot 0:bcf2aa85d7f9 31
nherriot 0:bcf2aa85d7f9 32
nherriot 0:bcf2aa85d7f9 33 // Destroys instance
ashleymills 6:f6bde04bf8be 34 Accelerometer_MMA8452::~Accelerometer_MMA8452()
nherriot 0:bcf2aa85d7f9 35 {
nherriot 0:bcf2aa85d7f9 36
nherriot 0:bcf2aa85d7f9 37 }
nherriot 0:bcf2aa85d7f9 38
nherriot 0:bcf2aa85d7f9 39 // Setting the control register bit 1 to true to activate the MMA8452
nherriot 0:bcf2aa85d7f9 40 int Accelerometer_MMA8452::activate()
nherriot 0:bcf2aa85d7f9 41 {
ashleymills 6:f6bde04bf8be 42 // set control register 1 to active
ashleymills 6:f6bde04bf8be 43 char init[2] = {CTRL_REG_1,ACTIVE};
nherriot 3:ffb0b1650ca2 44
ashleymills 6:f6bde04bf8be 45 // perform write and return error code
ashleymills 6:f6bde04bf8be 46 return m_i2c.write(_writeAddress,init,2);
nherriot 3:ffb0b1650ca2 47 }
nherriot 3:ffb0b1650ca2 48
nherriot 3:ffb0b1650ca2 49
nherriot 5:b3d0abd97e55 50 // Get 'Fast Read Mode' called F_READ. If bit 1 is set '1' then F_READ is active. Fast read will skip LSB when reading xyz
nherriot 5:b3d0abd97e55 51 // resisters from 0x01 to 0x06. When F_READ is '0' then all 6 registers will be read.
nherriot 5:b3d0abd97e55 52
ashleymills 6:f6bde04bf8be 53 int Accelerometer_MMA8452::get_CTRL_Reg1(int* CTRL_Reg)
nherriot 5:b3d0abd97e55 54 {
nherriot 5:b3d0abd97e55 55 char mcu_address = (MMA8452_ADDRESS<<1);
nherriot 5:b3d0abd97e55 56 m_i2c.start();
ashleymills 6:f6bde04bf8be 57 if( m_i2c.write(_writeAddress) == 0)
nherriot 5:b3d0abd97e55 58 {
nherriot 5:b3d0abd97e55 59 return 1; // we failed to write the mcu address on the bus to initiate dialogue
nherriot 5:b3d0abd97e55 60 }
nherriot 5:b3d0abd97e55 61 if( m_i2c.write( CTRL_REG_1) == 0)
nherriot 5:b3d0abd97e55 62 {
nherriot 5:b3d0abd97e55 63 return 1; // we failed to write 'status' to the chip
nherriot 5:b3d0abd97e55 64 }
nherriot 5:b3d0abd97e55 65 m_i2c.start();
nherriot 5:b3d0abd97e55 66 if( m_i2c.write( mcu_address | 0x01) == 0) // this is asking to read the slave mcu address - even though it's a 'write' method!!! Crap API...
nherriot 5:b3d0abd97e55 67 {
nherriot 5:b3d0abd97e55 68 return 1; // we failed to request a read from that mcu - this really is just writing the mcu vaule on the bus
nherriot 5:b3d0abd97e55 69 }
ashleymills 6:f6bde04bf8be 70 *CTRL_Reg = m_i2c.read(0);
nherriot 5:b3d0abd97e55 71 m_i2c.stop();
nherriot 5:b3d0abd97e55 72 return 0;
nherriot 5:b3d0abd97e55 73 }
nherriot 5:b3d0abd97e55 74
nherriot 3:ffb0b1650ca2 75 // Setting the control register bit 1 to true to activate the MMA8452
nherriot 3:ffb0b1650ca2 76 int Accelerometer_MMA8452::standby()
nherriot 3:ffb0b1650ca2 77 {
nherriot 3:ffb0b1650ca2 78 char mcu_address = (MMA8452_ADDRESS<<1);
nherriot 3:ffb0b1650ca2 79 char init[2];
nherriot 3:ffb0b1650ca2 80 init[0] = CTRL_REG_1; // control register 1
nherriot 3:ffb0b1650ca2 81 init[1] = STANDBY; // set to standby
nherriot 1:ef026bf28798 82
nherriot 0:bcf2aa85d7f9 83 if(m_i2c.write(mcu_address,init,2) == 0)
nherriot 0:bcf2aa85d7f9 84 {
nherriot 0:bcf2aa85d7f9 85 // pc.printf("The initialisation worked");
nherriot 1:ef026bf28798 86 return 0; // return 0 to indicate success
nherriot 0:bcf2aa85d7f9 87 }
nherriot 0:bcf2aa85d7f9 88 else
nherriot 0:bcf2aa85d7f9 89 {
nherriot 0:bcf2aa85d7f9 90 // pc.printf("The initialisation failed");
nherriot 1:ef026bf28798 91 return 1; // crumbs it failed!!!
nherriot 0:bcf2aa85d7f9 92 }
nherriot 0:bcf2aa85d7f9 93
nherriot 0:bcf2aa85d7f9 94 }
nherriot 0:bcf2aa85d7f9 95
nherriot 0:bcf2aa85d7f9 96
nherriot 3:ffb0b1650ca2 97
nherriot 0:bcf2aa85d7f9 98 // Device initialization
nherriot 0:bcf2aa85d7f9 99 void Accelerometer_MMA8452::init()
nherriot 0:bcf2aa85d7f9 100 {
nherriot 0:bcf2aa85d7f9 101
nherriot 0:bcf2aa85d7f9 102 write_reg(INTSU_STATUS, 0x10); // automatic interrupt after every measurement
nherriot 0:bcf2aa85d7f9 103 write_reg(SR_STATUS, 0x00); // 120 Samples/Second
nherriot 0:bcf2aa85d7f9 104 write_reg(MODE_STATUS, 0x01); // Active Mode
nherriot 0:bcf2aa85d7f9 105
nherriot 0:bcf2aa85d7f9 106 }
nherriot 0:bcf2aa85d7f9 107
nherriot 3:ffb0b1650ca2 108 // Get real time status of device - it can be STANDBY, WAKE or SLEEP
nherriot 3:ffb0b1650ca2 109 int Accelerometer_MMA8452::get_SystemMode(int& deviceSystemMode)
nherriot 3:ffb0b1650ca2 110 {
nherriot 3:ffb0b1650ca2 111 char mcu_address = (MMA8452_ADDRESS<<1);
nherriot 3:ffb0b1650ca2 112 m_i2c.start();
nherriot 3:ffb0b1650ca2 113 if( m_i2c.write( mcu_address & 0xFE) == 0) // just good practice to force bit 1 to a '0' by ANDing with 0xFE
nherriot 3:ffb0b1650ca2 114 {
nherriot 3:ffb0b1650ca2 115 return 1; // we failed to write the mcu address on the bus to initiate dialogue
nherriot 3:ffb0b1650ca2 116 }
nherriot 3:ffb0b1650ca2 117 if( m_i2c.write( SYSMOD) == 0)
nherriot 3:ffb0b1650ca2 118 {
nherriot 3:ffb0b1650ca2 119 return 1; // we failed to write 'status' to the chip
nherriot 3:ffb0b1650ca2 120 }
nherriot 3:ffb0b1650ca2 121 m_i2c.start();
nherriot 3:ffb0b1650ca2 122 if( m_i2c.write( mcu_address | 0x01) == 0) // this is asking to read the slave mcu address - even though it's a 'write' method!!! Crap API...
nherriot 3:ffb0b1650ca2 123 {
nherriot 3:ffb0b1650ca2 124 return 1; // we failed to request a read from that mcu - this really is just writing the mcu vaule on the bus
nherriot 3:ffb0b1650ca2 125 }
nherriot 3:ffb0b1650ca2 126 deviceSystemMode = m_i2c.read(0);
nherriot 3:ffb0b1650ca2 127 m_i2c.stop();
nherriot 3:ffb0b1650ca2 128 return 0;
nherriot 3:ffb0b1650ca2 129
nherriot 3:ffb0b1650ca2 130
nherriot 3:ffb0b1650ca2 131 }
nherriot 3:ffb0b1650ca2 132
nherriot 3:ffb0b1650ca2 133
nherriot 3:ffb0b1650ca2 134
nherriot 3:ffb0b1650ca2 135 // Get real time status of device - it can be STANDBY, WAKE or SLEEP
nherriot 3:ffb0b1650ca2 136 int Accelerometer_MMA8452::get_Status(int& deviceStatus)
nherriot 3:ffb0b1650ca2 137 {
nherriot 3:ffb0b1650ca2 138 char mcu_address = (MMA8452_ADDRESS<<1);
nherriot 3:ffb0b1650ca2 139 m_i2c.start();
nherriot 3:ffb0b1650ca2 140 if( m_i2c.write( mcu_address & 0xFE) == 0) // just good practice to force bit 1 to a '0' by ANDing with 0xFE
nherriot 3:ffb0b1650ca2 141 {
nherriot 3:ffb0b1650ca2 142 return 1; // we failed to write the mcu address on the bus to initiate dialogue
nherriot 3:ffb0b1650ca2 143 }
nherriot 3:ffb0b1650ca2 144 if( m_i2c.write( STATUS) == 0)
nherriot 3:ffb0b1650ca2 145 {
nherriot 3:ffb0b1650ca2 146 return 1; // we failed to write 'status' to the chip
nherriot 3:ffb0b1650ca2 147 }
nherriot 3:ffb0b1650ca2 148 m_i2c.start();
nherriot 3:ffb0b1650ca2 149 if( m_i2c.write( mcu_address | 0x01) == 0) // this is asking to read the slave mcu address - even though it's a 'write' method!!! Crap API...
nherriot 3:ffb0b1650ca2 150 {
nherriot 3:ffb0b1650ca2 151 return 1; // we failed to request a read from that mcu - this really is just writing the mcu vaule on the bus
nherriot 3:ffb0b1650ca2 152 }
nherriot 3:ffb0b1650ca2 153 deviceStatus = m_i2c.read(0);
nherriot 3:ffb0b1650ca2 154 m_i2c.stop();
nherriot 3:ffb0b1650ca2 155 return 0;
nherriot 3:ffb0b1650ca2 156
nherriot 3:ffb0b1650ca2 157
nherriot 3:ffb0b1650ca2 158 }
nherriot 3:ffb0b1650ca2 159
nherriot 0:bcf2aa85d7f9 160
nherriot 1:ef026bf28798 161 // Get device ID
nherriot 2:66db0f91b215 162 int Accelerometer_MMA8452::get_DeviceID(int& deviceID)
nherriot 1:ef026bf28798 163 {
nherriot 1:ef026bf28798 164 char mcu_address = (MMA8452_ADDRESS<<1);
nherriot 1:ef026bf28798 165 m_i2c.start();
nherriot 3:ffb0b1650ca2 166 if( m_i2c.write( mcu_address & 0xFE) == 0) // just good practice to force bit 1 to a '0' by ANDing with 0xFE
nherriot 1:ef026bf28798 167 {
nherriot 3:ffb0b1650ca2 168 return 1; // we failed to write the mcu address on the bus to initiate dialogue
nherriot 1:ef026bf28798 169 }
nherriot 1:ef026bf28798 170 if( m_i2c.write( WHO_AM_I) == 0)
nherriot 1:ef026bf28798 171 {
nherriot 3:ffb0b1650ca2 172 return 1; // we failed to write 'who am i' to the chip
nherriot 1:ef026bf28798 173 }
nherriot 1:ef026bf28798 174 m_i2c.start();
nherriot 3:ffb0b1650ca2 175 if( m_i2c.write( mcu_address | 0x01) == 0) // this is asking to read the slave mcu address - even though it's a 'write' method!!! Crap API...
nherriot 1:ef026bf28798 176 {
nherriot 3:ffb0b1650ca2 177 return 1; // we failed to request a read from that mcu - this really is just writing the mcu vaule on the bus
nherriot 1:ef026bf28798 178 }
nherriot 2:66db0f91b215 179 deviceID = m_i2c.read(0);
nherriot 1:ef026bf28798 180 m_i2c.stop();
nherriot 1:ef026bf28798 181 return 0;
nherriot 1:ef026bf28798 182
nherriot 1:ef026bf28798 183 }
nherriot 1:ef026bf28798 184
nherriot 1:ef026bf28798 185
nherriot 3:ffb0b1650ca2 186 /*
nherriot 3:ffb0b1650ca2 187 // Reads x data
nherriot 3:ffb0b1650ca2 188 int Accelerometer_MMA8452::read_x(int& xaxisLSB)
nherriot 0:bcf2aa85d7f9 189 {
nherriot 3:ffb0b1650ca2 190 char mcu_address = (MMA8452_ADDRESS<<1);
nherriot 3:ffb0b1650ca2 191 m_i2c.start();
nherriot 3:ffb0b1650ca2 192 if( m_i2c.write( mcu_address & 0xFE) == 0) // just good practice to force bit 1 to a '0' by ANDing with 0xFE
nherriot 3:ffb0b1650ca2 193 {
nherriot 3:ffb0b1650ca2 194 return 1; // we failed to write the mcu address on the bus to initiate dialogue
nherriot 3:ffb0b1650ca2 195 }
nherriot 3:ffb0b1650ca2 196 if( m_i2c.write( OUT_X_MSB) == 0)
nherriot 3:ffb0b1650ca2 197 {
nherriot 3:ffb0b1650ca2 198 return 1; // we failed to write 'X axis LSB' to the chip
nherriot 3:ffb0b1650ca2 199 }
nherriot 3:ffb0b1650ca2 200 m_i2c.start();
nherriot 3:ffb0b1650ca2 201 if( m_i2c.write( mcu_address | 0x01) == 0) // this is asking to read the slave mcu address - even though it's a 'write' method!!! Crap API...
nherriot 3:ffb0b1650ca2 202 {
nherriot 3:ffb0b1650ca2 203 return 1; // we failed to request a read from that mcu - this really is just writing the mcu vaule on the bus
nherriot 3:ffb0b1650ca2 204 }
nherriot 3:ffb0b1650ca2 205 xaxisLSB = m_i2c.read(0);
nherriot 3:ffb0b1650ca2 206 m_i2c.stop();
nherriot 3:ffb0b1650ca2 207 return 0;
nherriot 3:ffb0b1650ca2 208 }
nherriot 3:ffb0b1650ca2 209 */
nherriot 0:bcf2aa85d7f9 210
nherriot 3:ffb0b1650ca2 211
nherriot 3:ffb0b1650ca2 212 // Reads x data. This method reads two registers containing the x-axis values from the accelerometer.
nherriot 3:ffb0b1650ca2 213 // It takes a 2 byte char array and copies the register values into the buffer. If it fails the char array
nherriot 3:ffb0b1650ca2 214 // is set to '0'. It returns '0' success '1' fail. This method does nothing to the registers - just returns
nherriot 3:ffb0b1650ca2 215 // the raw data.
nherriot 3:ffb0b1650ca2 216 //int Accelerometer_MMA8452::read_x(int& xaxisLSB)
nherriot 3:ffb0b1650ca2 217 int Accelerometer_MMA8452::read_x_raw(char *xaxis)
nherriot 3:ffb0b1650ca2 218 {
nherriot 3:ffb0b1650ca2 219 char mcu_address = (MMA8452_ADDRESS<<1); // this is the slave address on the bus we want data from
nherriot 3:ffb0b1650ca2 220 char xaxis_buffer[2]; // this will contain data from that register
nherriot 3:ffb0b1650ca2 221 char xaxis_register[1];
nherriot 3:ffb0b1650ca2 222 xaxis_register[0] = OUT_X_MSB; // this is the register we want to get data from
nherriot 3:ffb0b1650ca2 223 //signed short s = 0;
nherriot 0:bcf2aa85d7f9 224
nherriot 3:ffb0b1650ca2 225 if(m_i2c.write(mcu_address,xaxis_register,1) == 0)
nherriot 3:ffb0b1650ca2 226 {
nherriot 3:ffb0b1650ca2 227 if(m_i2c.read(mcu_address,xaxis_buffer,2) == 0)
nherriot 3:ffb0b1650ca2 228 {
nherriot 3:ffb0b1650ca2 229 //strcpy(xaxis, xaxis_buffer);
nherriot 3:ffb0b1650ca2 230 memcpy(xaxis, xaxis_buffer, 2);
nherriot 3:ffb0b1650ca2 231 //xaxis[0] = 0x00; // make sure the array is set to zero
nherriot 3:ffb0b1650ca2 232 //xaxis[1] = 0x00;
nherriot 3:ffb0b1650ca2 233 //s = *reinterpret_cast<short*>(&xaxis);
nherriot 3:ffb0b1650ca2 234 return 0; // great we got the two octets
nherriot 3:ffb0b1650ca2 235 }
nherriot 3:ffb0b1650ca2 236 else
nherriot 3:ffb0b1650ca2 237 {
nherriot 3:ffb0b1650ca2 238 xaxis[0] = 0x00; // make sure the array is set to zero
nherriot 3:ffb0b1650ca2 239 xaxis[1] = 0x00;
nherriot 3:ffb0b1650ca2 240 return 1; // failed to read the 12 bit x value
nherriot 3:ffb0b1650ca2 241 }
nherriot 3:ffb0b1650ca2 242 }
nherriot 3:ffb0b1650ca2 243 else
nherriot 3:ffb0b1650ca2 244 {
nherriot 3:ffb0b1650ca2 245 xaxis[0] = 0x00; // make sure the array is set to zero
nherriot 3:ffb0b1650ca2 246 xaxis[1] = 0x00;
nherriot 3:ffb0b1650ca2 247 return 1; // failed to write and request the OUT_X_MSB bit
nherriot 3:ffb0b1650ca2 248 }
nherriot 0:bcf2aa85d7f9 249 }
nherriot 0:bcf2aa85d7f9 250
nherriot 0:bcf2aa85d7f9 251
nherriot 3:ffb0b1650ca2 252 // Reads y data. This method reads two registers containing the x-axis values from the accelerometer.
nherriot 3:ffb0b1650ca2 253 // It takes a 2 byte char array and copies the register values into the buffer. If it fails the char array
nherriot 3:ffb0b1650ca2 254 // is set to '0'. It returns '0' success '1' fail. This method does nothing to the registers - just returns
nherriot 3:ffb0b1650ca2 255 // the raw data.
nherriot 3:ffb0b1650ca2 256
nherriot 3:ffb0b1650ca2 257 int Accelerometer_MMA8452::read_y_raw(char *yaxis)
nherriot 0:bcf2aa85d7f9 258 {
nherriot 3:ffb0b1650ca2 259 char mcu_address = (MMA8452_ADDRESS<<1); // this is the slave address on the bus we want data from
nherriot 3:ffb0b1650ca2 260 char yaxis_buffer[2]; // this will contain data from that register
nherriot 3:ffb0b1650ca2 261 char yaxis_register[1];
nherriot 3:ffb0b1650ca2 262 yaxis_register[0] = OUT_Y_MSB; // this is the register we want to get data from
nherriot 3:ffb0b1650ca2 263 //signed short s = 0;
nherriot 3:ffb0b1650ca2 264
nherriot 3:ffb0b1650ca2 265 if(m_i2c.write(mcu_address,yaxis_register,1) == 0)
nherriot 3:ffb0b1650ca2 266 {
nherriot 3:ffb0b1650ca2 267 if(m_i2c.read(mcu_address,yaxis_buffer,2) == 0)
nherriot 3:ffb0b1650ca2 268 {
nherriot 3:ffb0b1650ca2 269 //strcpy(yaxis, yaxis_buffer);
nherriot 3:ffb0b1650ca2 270 memcpy(yaxis, yaxis_buffer, 2);
nherriot 3:ffb0b1650ca2 271 //yaxis[0] = 0x00; // make sure the array is set to zero
nherriot 3:ffb0b1650ca2 272 //yaxis[1] = 0x00;
nherriot 3:ffb0b1650ca2 273 //s = *reinterpret_cast<short*>(&xaxis);
nherriot 3:ffb0b1650ca2 274 return 0; // great we got the two octets
nherriot 3:ffb0b1650ca2 275 }
nherriot 3:ffb0b1650ca2 276 else
nherriot 3:ffb0b1650ca2 277 {
nherriot 3:ffb0b1650ca2 278 yaxis[0] = 0x00; // make sure the array is set to zero
nherriot 3:ffb0b1650ca2 279 yaxis[1] = 0x00;
nherriot 3:ffb0b1650ca2 280 return 1; // failed to read the 12 bit y value
nherriot 3:ffb0b1650ca2 281 }
nherriot 3:ffb0b1650ca2 282 }
nherriot 3:ffb0b1650ca2 283 else
nherriot 3:ffb0b1650ca2 284 {
nherriot 3:ffb0b1650ca2 285 yaxis[0] = 0x00; // make sure the array is set to zero
nherriot 3:ffb0b1650ca2 286 yaxis[1] = 0x00;
nherriot 3:ffb0b1650ca2 287 return 1; // failed to write and request the OUT_Y_MSB bit
nherriot 3:ffb0b1650ca2 288 }
nherriot 3:ffb0b1650ca2 289 }
nherriot 3:ffb0b1650ca2 290
nherriot 0:bcf2aa85d7f9 291
nherriot 3:ffb0b1650ca2 292
nherriot 3:ffb0b1650ca2 293 // Reads z data. This method reads two registers containing the x-axis values from the accelerometer.
nherriot 3:ffb0b1650ca2 294 // It takes a 2 byte char array and copies the register values into the buffer. If it fails the char array
nherriot 3:ffb0b1650ca2 295 // is set to '0'. It returns '0' success '1' fail. This method does nothing to the registers - just returns
nherriot 3:ffb0b1650ca2 296 // the raw data.
nherriot 3:ffb0b1650ca2 297
nherriot 3:ffb0b1650ca2 298 int Accelerometer_MMA8452::read_z_raw(char *zaxis)
nherriot 3:ffb0b1650ca2 299 {
nherriot 3:ffb0b1650ca2 300 char mcu_address = (MMA8452_ADDRESS<<1); // this is the slave address on the bus we want data from
nherriot 3:ffb0b1650ca2 301 char zaxis_buffer[2]; // this will contain data from that register
nherriot 3:ffb0b1650ca2 302 char zaxis_register[1];
nherriot 3:ffb0b1650ca2 303 zaxis_register[0] = OUT_Z_MSB; // this is the register we want to get data from
nherriot 3:ffb0b1650ca2 304 //signed short s = 0;
nherriot 0:bcf2aa85d7f9 305
nherriot 3:ffb0b1650ca2 306 if(m_i2c.write(mcu_address,zaxis_register,1) == 0)
nherriot 3:ffb0b1650ca2 307 {
nherriot 4:27aa3cd43234 308 //if(m_i2c.read(mcu_address,zaxis_buffer,2) == 0)
nherriot 4:27aa3cd43234 309 if(m_i2c.read(mcu_address,zaxis,2) == 0)
nherriot 3:ffb0b1650ca2 310 {
nherriot 3:ffb0b1650ca2 311 //strcpy(yaxis, yaxis_buffer);
nherriot 4:27aa3cd43234 312 //memcpy(zaxis, zaxis_buffer, 2);
nherriot 3:ffb0b1650ca2 313 //yaxis[0] = 0x00; // make sure the array is set to zero
nherriot 3:ffb0b1650ca2 314 //yaxis[1] = 0x00;
nherriot 3:ffb0b1650ca2 315 //s = *reinterpret_cast<short*>(&xaxis);
nherriot 3:ffb0b1650ca2 316 return 0; // great we got the two octets
nherriot 3:ffb0b1650ca2 317 }
nherriot 3:ffb0b1650ca2 318 else
nherriot 3:ffb0b1650ca2 319 {
nherriot 3:ffb0b1650ca2 320 zaxis[0] = 0x00; // make sure the array is set to zero
nherriot 3:ffb0b1650ca2 321 zaxis[1] = 0x00;
nherriot 3:ffb0b1650ca2 322 return 1; // failed to read the 12 bit y value
nherriot 3:ffb0b1650ca2 323 }
nherriot 3:ffb0b1650ca2 324 }
nherriot 3:ffb0b1650ca2 325 else
nherriot 3:ffb0b1650ca2 326 {
nherriot 3:ffb0b1650ca2 327 zaxis[0] = 0x00; // make sure the array is set to zero
nherriot 3:ffb0b1650ca2 328 zaxis[1] = 0x00;
nherriot 3:ffb0b1650ca2 329 return 1; // failed to write and request the OUT_Y_MSB bit
nherriot 3:ffb0b1650ca2 330 }
nherriot 3:ffb0b1650ca2 331 }
nherriot 0:bcf2aa85d7f9 332
nherriot 0:bcf2aa85d7f9 333
nherriot 0:bcf2aa85d7f9 334
nherriot 0:bcf2aa85d7f9 335 // Reads y data
nherriot 0:bcf2aa85d7f9 336 int Accelerometer_MMA8452::read_y()
nherriot 0:bcf2aa85d7f9 337 {
nherriot 1:ef026bf28798 338 char mcu_address = (MMA8452_ADDRESS <<1);
nherriot 0:bcf2aa85d7f9 339
nherriot 0:bcf2aa85d7f9 340 m_i2c.start(); // Start
nherriot 0:bcf2aa85d7f9 341 m_i2c.write(mcu_address); // A write to device 0x98
nherriot 0:bcf2aa85d7f9 342 m_i2c.write(OUT_Y_MSB); // Register to read
nherriot 0:bcf2aa85d7f9 343 m_i2c.start();
nherriot 0:bcf2aa85d7f9 344 m_i2c.write(mcu_address); // Read from device 0x99
nherriot 1:ef026bf28798 345 int y = m_i2c.read(0); // Read the data
nherriot 0:bcf2aa85d7f9 346 m_i2c.stop();
nherriot 0:bcf2aa85d7f9 347
nherriot 1:ef026bf28798 348 return y;
nherriot 0:bcf2aa85d7f9 349
nherriot 0:bcf2aa85d7f9 350 }
nherriot 0:bcf2aa85d7f9 351
nherriot 0:bcf2aa85d7f9 352
nherriot 0:bcf2aa85d7f9 353 // Reads z data
nherriot 0:bcf2aa85d7f9 354 int Accelerometer_MMA8452::read_z()
nherriot 0:bcf2aa85d7f9 355 {
nherriot 1:ef026bf28798 356 char mcu_address = (MMA8452_ADDRESS <<1);
nherriot 0:bcf2aa85d7f9 357
nherriot 0:bcf2aa85d7f9 358 m_i2c.start(); // Start
nherriot 0:bcf2aa85d7f9 359 m_i2c.write(mcu_address); // A write to device 0x98
nherriot 0:bcf2aa85d7f9 360 m_i2c.write(OUT_Z_MSB); // Register to read
nherriot 0:bcf2aa85d7f9 361 m_i2c.start();
nherriot 0:bcf2aa85d7f9 362 m_i2c.write(mcu_address); // Read from device 0x99
nherriot 1:ef026bf28798 363 int z = m_i2c.read(0); // Read the data
nherriot 0:bcf2aa85d7f9 364 m_i2c.stop();
nherriot 0:bcf2aa85d7f9 365
nherriot 1:ef026bf28798 366 return z;
nherriot 0:bcf2aa85d7f9 367
nherriot 0:bcf2aa85d7f9 368 }
nherriot 0:bcf2aa85d7f9 369
nherriot 0:bcf2aa85d7f9 370
nherriot 0:bcf2aa85d7f9 371 // Reads xyz
nherriot 1:ef026bf28798 372 int Accelerometer_MMA8452::read_xyz(char *x, char *y, char *z)
nherriot 1:ef026bf28798 373 {
nherriot 1:ef026bf28798 374
nherriot 1:ef026bf28798 375
nherriot 1:ef026bf28798 376 char mcu_address = (MMA8452_ADDRESS <<1);
nherriot 1:ef026bf28798 377 char register_buffer[6] ={0,0,0,0,0,0};
nherriot 1:ef026bf28798 378 const char Addr_X = OUT_X_MSB;
nherriot 1:ef026bf28798 379 m_i2c.write(mcu_address); // A write to device 0x98
nherriot 1:ef026bf28798 380 m_i2c.write(MMA8452_ADDRESS, &Addr_X, 1); // Pointer to the OUT_X_MSB register
nherriot 1:ef026bf28798 381
nherriot 1:ef026bf28798 382 if(m_i2c.write(mcu_address,&Addr_X,1) == 0)
nherriot 1:ef026bf28798 383 {
nherriot 1:ef026bf28798 384 if(m_i2c.read(mcu_address,register_buffer,6) == 0)
nherriot 1:ef026bf28798 385 {
nherriot 1:ef026bf28798 386 *x = register_buffer[1];
nherriot 1:ef026bf28798 387 *y = register_buffer[3];
nherriot 1:ef026bf28798 388 *z = register_buffer[5];
nherriot 1:ef026bf28798 389 return 0; // yahoooooo
nherriot 1:ef026bf28798 390 }
nherriot 1:ef026bf28798 391 else
nherriot 1:ef026bf28798 392 {
nherriot 1:ef026bf28798 393 return 1; // failed oh nooo!
nherriot 1:ef026bf28798 394 }
nherriot 1:ef026bf28798 395 }
nherriot 1:ef026bf28798 396 else
nherriot 1:ef026bf28798 397 {
nherriot 1:ef026bf28798 398 return 1; // failed oh nooo!
nherriot 1:ef026bf28798 399 }
nherriot 0:bcf2aa85d7f9 400
nherriot 1:ef026bf28798 401 }
nherriot 0:bcf2aa85d7f9 402
nherriot 0:bcf2aa85d7f9 403 // Write register (The device must be placed in Standby Mode to change the value of the registers)
nherriot 0:bcf2aa85d7f9 404 void Accelerometer_MMA8452::write_reg(char addr, char data)
nherriot 0:bcf2aa85d7f9 405 {
nherriot 0:bcf2aa85d7f9 406
nherriot 0:bcf2aa85d7f9 407 char cmd[2] = {0, 0};
nherriot 0:bcf2aa85d7f9 408
nherriot 0:bcf2aa85d7f9 409 cmd[0] = MODE_STATUS;
nherriot 0:bcf2aa85d7f9 410 cmd[1] = 0x00; // Standby Mode on
nherriot 0:bcf2aa85d7f9 411 m_i2c.write(MMA8452_ADDRESS, cmd, 2);
nherriot 0:bcf2aa85d7f9 412
nherriot 0:bcf2aa85d7f9 413 cmd[0] = addr;
nherriot 0:bcf2aa85d7f9 414 cmd[1] = data; // New value of the register
nherriot 0:bcf2aa85d7f9 415 m_i2c.write(MMA8452_ADDRESS, cmd, 2);
nherriot 0:bcf2aa85d7f9 416
nherriot 0:bcf2aa85d7f9 417 cmd[0] = MODE_STATUS;
nherriot 0:bcf2aa85d7f9 418 cmd[1] = 0x01; // Active Mode on
nherriot 0:bcf2aa85d7f9 419 m_i2c.write(MMA8452_ADDRESS, cmd, 2);
nherriot 0:bcf2aa85d7f9 420
nherriot 0:bcf2aa85d7f9 421 }
nherriot 0:bcf2aa85d7f9 422
nherriot 0:bcf2aa85d7f9 423
nherriot 0:bcf2aa85d7f9 424
nherriot 0:bcf2aa85d7f9 425 // Read from specified MMA7660FC register
nherriot 0:bcf2aa85d7f9 426 char Accelerometer_MMA8452::read_reg(char addr)
nherriot 0:bcf2aa85d7f9 427 {
nherriot 0:bcf2aa85d7f9 428
nherriot 0:bcf2aa85d7f9 429 m_i2c.start(); // Start
nherriot 0:bcf2aa85d7f9 430 m_i2c.write(0x98); // A write to device 0x98
nherriot 0:bcf2aa85d7f9 431 m_i2c.write(addr); // Register to read
nherriot 0:bcf2aa85d7f9 432 m_i2c.start();
nherriot 0:bcf2aa85d7f9 433 m_i2c.write(0x99); // Read from device 0x99
nherriot 0:bcf2aa85d7f9 434 char c = m_i2c.read(0); // Read the data
nherriot 0:bcf2aa85d7f9 435 m_i2c.stop();
nherriot 0:bcf2aa85d7f9 436
nherriot 0:bcf2aa85d7f9 437 return c;
nherriot 0:bcf2aa85d7f9 438
nherriot 0:bcf2aa85d7f9 439 }
nherriot 0:bcf2aa85d7f9 440
nherriot 0:bcf2aa85d7f9 441
nherriot 0:bcf2aa85d7f9 442
nherriot 0:bcf2aa85d7f9 443
nherriot 0:bcf2aa85d7f9 444
nherriot 0:bcf2aa85d7f9 445