Nicholas Herriot / MMA8452

This is a simple device driver for the 3 axis accelerometer MMA8452 that works with mbed.

Dependents:   MMA8452_test S05APP3_routeur

MMA8452.cpp@4:27aa3cd43234, 2013-10-16 (annotated)

Committer:
nherriot
Date:
Wed Oct 16 16:26:26 2013 +0000
Revision:
4:27aa3cd43234
Parent:
3:ffb0b1650ca2
Child:
5:b3d0abd97e55
simplification on several methods.

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
nherriot 0:bcf2aa85d7f9 23
nherriot 0:bcf2aa85d7f9 24
nherriot 0:bcf2aa85d7f9 25
nherriot 0:bcf2aa85d7f9 26
nherriot 0:bcf2aa85d7f9 27 // Connect module at I2C address using I2C port pins sda and scl
nherriot 1:ef026bf28798 28 Accelerometer_MMA8452::Accelerometer_MMA8452(PinName sda, PinName scl,int frequency) : m_i2c(sda, scl) , m_frequency(frequency)
nherriot 0:bcf2aa85d7f9 29 {
nherriot 0:bcf2aa85d7f9 30 //m_i2c.frequency(m_frequency);
nherriot 0:bcf2aa85d7f9 31 }
nherriot 0:bcf2aa85d7f9 32
nherriot 0:bcf2aa85d7f9 33
nherriot 0:bcf2aa85d7f9 34 // Destroys instance
nherriot 0:bcf2aa85d7f9 35 Accelerometer_MMA8452::~Accelerometer_MMA8452()
nherriot 0:bcf2aa85d7f9 36 {
nherriot 0:bcf2aa85d7f9 37
nherriot 0:bcf2aa85d7f9 38 }
nherriot 0:bcf2aa85d7f9 39
nherriot 0:bcf2aa85d7f9 40 // Setting the control register bit 1 to true to activate the MMA8452
nherriot 0:bcf2aa85d7f9 41 int Accelerometer_MMA8452::activate()
nherriot 0:bcf2aa85d7f9 42 {
nherriot 1:ef026bf28798 43 char mcu_address = (MMA8452_ADDRESS<<1);
nherriot 0:bcf2aa85d7f9 44 char init[2];
nherriot 0:bcf2aa85d7f9 45 init[0] = CTRL_REG_1; // control register 1
nherriot 3:ffb0b1650ca2 46 init[1] = ACTIVE; // set to active
nherriot 3:ffb0b1650ca2 47
nherriot 3:ffb0b1650ca2 48 if(m_i2c.write(mcu_address,init,2) == 0)
nherriot 3:ffb0b1650ca2 49 {
nherriot 3:ffb0b1650ca2 50 return 0; // return 0 to indicate success
nherriot 3:ffb0b1650ca2 51 }
nherriot 3:ffb0b1650ca2 52 else
nherriot 3:ffb0b1650ca2 53 {
nherriot 3:ffb0b1650ca2 54 return 1; // crumbs it failed!!!
nherriot 3:ffb0b1650ca2 55 }
nherriot 3:ffb0b1650ca2 56
nherriot 3:ffb0b1650ca2 57 }
nherriot 3:ffb0b1650ca2 58
nherriot 3:ffb0b1650ca2 59
nherriot 3:ffb0b1650ca2 60 // Setting the control register bit 1 to true to activate the MMA8452
nherriot 3:ffb0b1650ca2 61 int Accelerometer_MMA8452::standby()
nherriot 3:ffb0b1650ca2 62 {
nherriot 3:ffb0b1650ca2 63 char mcu_address = (MMA8452_ADDRESS<<1);
nherriot 3:ffb0b1650ca2 64 char init[2];
nherriot 3:ffb0b1650ca2 65 init[0] = CTRL_REG_1; // control register 1
nherriot 3:ffb0b1650ca2 66 init[1] = STANDBY; // set to standby
nherriot 1:ef026bf28798 67
nherriot 0:bcf2aa85d7f9 68 if(m_i2c.write(mcu_address,init,2) == 0)
nherriot 0:bcf2aa85d7f9 69 {
nherriot 0:bcf2aa85d7f9 70 // pc.printf("The initialisation worked");
nherriot 1:ef026bf28798 71 return 0; // return 0 to indicate success
nherriot 0:bcf2aa85d7f9 72 }
nherriot 0:bcf2aa85d7f9 73 else
nherriot 0:bcf2aa85d7f9 74 {
nherriot 0:bcf2aa85d7f9 75 // pc.printf("The initialisation failed");
nherriot 1:ef026bf28798 76 return 1; // crumbs it failed!!!
nherriot 0:bcf2aa85d7f9 77 }
nherriot 0:bcf2aa85d7f9 78
nherriot 0:bcf2aa85d7f9 79 }
nherriot 0:bcf2aa85d7f9 80
nherriot 0:bcf2aa85d7f9 81
nherriot 3:ffb0b1650ca2 82
nherriot 0:bcf2aa85d7f9 83 // Device initialization
nherriot 0:bcf2aa85d7f9 84 void Accelerometer_MMA8452::init()
nherriot 0:bcf2aa85d7f9 85 {
nherriot 0:bcf2aa85d7f9 86
nherriot 0:bcf2aa85d7f9 87 write_reg(INTSU_STATUS, 0x10); // automatic interrupt after every measurement
nherriot 0:bcf2aa85d7f9 88 write_reg(SR_STATUS, 0x00); // 120 Samples/Second
nherriot 0:bcf2aa85d7f9 89 write_reg(MODE_STATUS, 0x01); // Active Mode
nherriot 0:bcf2aa85d7f9 90
nherriot 0:bcf2aa85d7f9 91 }
nherriot 0:bcf2aa85d7f9 92
nherriot 3:ffb0b1650ca2 93 // Get real time status of device - it can be STANDBY, WAKE or SLEEP
nherriot 3:ffb0b1650ca2 94 int Accelerometer_MMA8452::get_SystemMode(int& deviceSystemMode)
nherriot 3:ffb0b1650ca2 95 {
nherriot 3:ffb0b1650ca2 96 char mcu_address = (MMA8452_ADDRESS<<1);
nherriot 3:ffb0b1650ca2 97 m_i2c.start();
nherriot 3:ffb0b1650ca2 98 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 99 {
nherriot 3:ffb0b1650ca2 100 return 1; // we failed to write the mcu address on the bus to initiate dialogue
nherriot 3:ffb0b1650ca2 101 }
nherriot 3:ffb0b1650ca2 102 if( m_i2c.write( SYSMOD) == 0)
nherriot 3:ffb0b1650ca2 103 {
nherriot 3:ffb0b1650ca2 104 return 1; // we failed to write 'status' to the chip
nherriot 3:ffb0b1650ca2 105 }
nherriot 3:ffb0b1650ca2 106 m_i2c.start();
nherriot 3:ffb0b1650ca2 107 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 108 {
nherriot 3:ffb0b1650ca2 109 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 110 }
nherriot 3:ffb0b1650ca2 111 deviceSystemMode = m_i2c.read(0);
nherriot 3:ffb0b1650ca2 112 m_i2c.stop();
nherriot 3:ffb0b1650ca2 113 return 0;
nherriot 3:ffb0b1650ca2 114
nherriot 3:ffb0b1650ca2 115
nherriot 3:ffb0b1650ca2 116 }
nherriot 3:ffb0b1650ca2 117
nherriot 3:ffb0b1650ca2 118
nherriot 3:ffb0b1650ca2 119
nherriot 3:ffb0b1650ca2 120 // Get real time status of device - it can be STANDBY, WAKE or SLEEP
nherriot 3:ffb0b1650ca2 121 int Accelerometer_MMA8452::get_Status(int& deviceStatus)
nherriot 3:ffb0b1650ca2 122 {
nherriot 3:ffb0b1650ca2 123 char mcu_address = (MMA8452_ADDRESS<<1);
nherriot 3:ffb0b1650ca2 124 m_i2c.start();
nherriot 3:ffb0b1650ca2 125 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 126 {
nherriot 3:ffb0b1650ca2 127 return 1; // we failed to write the mcu address on the bus to initiate dialogue
nherriot 3:ffb0b1650ca2 128 }
nherriot 3:ffb0b1650ca2 129 if( m_i2c.write( STATUS) == 0)
nherriot 3:ffb0b1650ca2 130 {
nherriot 3:ffb0b1650ca2 131 return 1; // we failed to write 'status' to the chip
nherriot 3:ffb0b1650ca2 132 }
nherriot 3:ffb0b1650ca2 133 m_i2c.start();
nherriot 3:ffb0b1650ca2 134 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 135 {
nherriot 3:ffb0b1650ca2 136 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 137 }
nherriot 3:ffb0b1650ca2 138 deviceStatus = m_i2c.read(0);
nherriot 3:ffb0b1650ca2 139 m_i2c.stop();
nherriot 3:ffb0b1650ca2 140 return 0;
nherriot 3:ffb0b1650ca2 141
nherriot 3:ffb0b1650ca2 142
nherriot 3:ffb0b1650ca2 143 }
nherriot 3:ffb0b1650ca2 144
nherriot 0:bcf2aa85d7f9 145
nherriot 1:ef026bf28798 146 // Get device ID
nherriot 2:66db0f91b215 147 int Accelerometer_MMA8452::get_DeviceID(int& deviceID)
nherriot 1:ef026bf28798 148 {
nherriot 1:ef026bf28798 149 char mcu_address = (MMA8452_ADDRESS<<1);
nherriot 1:ef026bf28798 150 m_i2c.start();
nherriot 3:ffb0b1650ca2 151 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 152 {
nherriot 3:ffb0b1650ca2 153 return 1; // we failed to write the mcu address on the bus to initiate dialogue
nherriot 1:ef026bf28798 154 }
nherriot 1:ef026bf28798 155 if( m_i2c.write( WHO_AM_I) == 0)
nherriot 1:ef026bf28798 156 {
nherriot 3:ffb0b1650ca2 157 return 1; // we failed to write 'who am i' to the chip
nherriot 1:ef026bf28798 158 }
nherriot 1:ef026bf28798 159 m_i2c.start();
nherriot 3:ffb0b1650ca2 160 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 161 {
nherriot 3:ffb0b1650ca2 162 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 163 }
nherriot 2:66db0f91b215 164 deviceID = m_i2c.read(0);
nherriot 1:ef026bf28798 165 m_i2c.stop();
nherriot 1:ef026bf28798 166 return 0;
nherriot 1:ef026bf28798 167
nherriot 1:ef026bf28798 168 }
nherriot 1:ef026bf28798 169
nherriot 1:ef026bf28798 170
nherriot 3:ffb0b1650ca2 171 /*
nherriot 3:ffb0b1650ca2 172 // Reads x data
nherriot 3:ffb0b1650ca2 173 int Accelerometer_MMA8452::read_x(int& xaxisLSB)
nherriot 0:bcf2aa85d7f9 174 {
nherriot 3:ffb0b1650ca2 175 char mcu_address = (MMA8452_ADDRESS<<1);
nherriot 3:ffb0b1650ca2 176 m_i2c.start();
nherriot 3:ffb0b1650ca2 177 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 178 {
nherriot 3:ffb0b1650ca2 179 return 1; // we failed to write the mcu address on the bus to initiate dialogue
nherriot 3:ffb0b1650ca2 180 }
nherriot 3:ffb0b1650ca2 181 if( m_i2c.write( OUT_X_MSB) == 0)
nherriot 3:ffb0b1650ca2 182 {
nherriot 3:ffb0b1650ca2 183 return 1; // we failed to write 'X axis LSB' to the chip
nherriot 3:ffb0b1650ca2 184 }
nherriot 3:ffb0b1650ca2 185 m_i2c.start();
nherriot 3:ffb0b1650ca2 186 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 187 {
nherriot 3:ffb0b1650ca2 188 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 189 }
nherriot 3:ffb0b1650ca2 190 xaxisLSB = m_i2c.read(0);
nherriot 3:ffb0b1650ca2 191 m_i2c.stop();
nherriot 3:ffb0b1650ca2 192 return 0;
nherriot 3:ffb0b1650ca2 193 }
nherriot 3:ffb0b1650ca2 194 */
nherriot 0:bcf2aa85d7f9 195
nherriot 3:ffb0b1650ca2 196
nherriot 3:ffb0b1650ca2 197 // Reads x data. This method reads two registers containing the x-axis values from the accelerometer.
nherriot 3:ffb0b1650ca2 198 // It takes a 2 byte char array and copies the register values into the buffer. If it fails the char array
nherriot 3:ffb0b1650ca2 199 // is set to '0'. It returns '0' success '1' fail. This method does nothing to the registers - just returns
nherriot 3:ffb0b1650ca2 200 // the raw data.
nherriot 3:ffb0b1650ca2 201 //int Accelerometer_MMA8452::read_x(int& xaxisLSB)
nherriot 3:ffb0b1650ca2 202 int Accelerometer_MMA8452::read_x_raw(char *xaxis)
nherriot 3:ffb0b1650ca2 203 {
nherriot 3:ffb0b1650ca2 204 char mcu_address = (MMA8452_ADDRESS<<1); // this is the slave address on the bus we want data from
nherriot 3:ffb0b1650ca2 205 char xaxis_buffer[2]; // this will contain data from that register
nherriot 3:ffb0b1650ca2 206 char xaxis_register[1];
nherriot 3:ffb0b1650ca2 207 xaxis_register[0] = OUT_X_MSB; // this is the register we want to get data from
nherriot 3:ffb0b1650ca2 208 //signed short s = 0;
nherriot 0:bcf2aa85d7f9 209
nherriot 3:ffb0b1650ca2 210 if(m_i2c.write(mcu_address,xaxis_register,1) == 0)
nherriot 3:ffb0b1650ca2 211 {
nherriot 3:ffb0b1650ca2 212 if(m_i2c.read(mcu_address,xaxis_buffer,2) == 0)
nherriot 3:ffb0b1650ca2 213 {
nherriot 3:ffb0b1650ca2 214 //strcpy(xaxis, xaxis_buffer);
nherriot 3:ffb0b1650ca2 215 memcpy(xaxis, xaxis_buffer, 2);
nherriot 3:ffb0b1650ca2 216 //xaxis[0] = 0x00; // make sure the array is set to zero
nherriot 3:ffb0b1650ca2 217 //xaxis[1] = 0x00;
nherriot 3:ffb0b1650ca2 218 //s = *reinterpret_cast<short*>(&xaxis);
nherriot 3:ffb0b1650ca2 219 return 0; // great we got the two octets
nherriot 3:ffb0b1650ca2 220 }
nherriot 3:ffb0b1650ca2 221 else
nherriot 3:ffb0b1650ca2 222 {
nherriot 3:ffb0b1650ca2 223 xaxis[0] = 0x00; // make sure the array is set to zero
nherriot 3:ffb0b1650ca2 224 xaxis[1] = 0x00;
nherriot 3:ffb0b1650ca2 225 return 1; // failed to read the 12 bit x value
nherriot 3:ffb0b1650ca2 226 }
nherriot 3:ffb0b1650ca2 227 }
nherriot 3:ffb0b1650ca2 228 else
nherriot 3:ffb0b1650ca2 229 {
nherriot 3:ffb0b1650ca2 230 xaxis[0] = 0x00; // make sure the array is set to zero
nherriot 3:ffb0b1650ca2 231 xaxis[1] = 0x00;
nherriot 3:ffb0b1650ca2 232 return 1; // failed to write and request the OUT_X_MSB bit
nherriot 3:ffb0b1650ca2 233 }
nherriot 0:bcf2aa85d7f9 234 }
nherriot 0:bcf2aa85d7f9 235
nherriot 0:bcf2aa85d7f9 236
nherriot 3:ffb0b1650ca2 237 // Reads y data. This method reads two registers containing the x-axis values from the accelerometer.
nherriot 3:ffb0b1650ca2 238 // It takes a 2 byte char array and copies the register values into the buffer. If it fails the char array
nherriot 3:ffb0b1650ca2 239 // is set to '0'. It returns '0' success '1' fail. This method does nothing to the registers - just returns
nherriot 3:ffb0b1650ca2 240 // the raw data.
nherriot 3:ffb0b1650ca2 241
nherriot 3:ffb0b1650ca2 242 int Accelerometer_MMA8452::read_y_raw(char *yaxis)
nherriot 0:bcf2aa85d7f9 243 {
nherriot 3:ffb0b1650ca2 244 char mcu_address = (MMA8452_ADDRESS<<1); // this is the slave address on the bus we want data from
nherriot 3:ffb0b1650ca2 245 char yaxis_buffer[2]; // this will contain data from that register
nherriot 3:ffb0b1650ca2 246 char yaxis_register[1];
nherriot 3:ffb0b1650ca2 247 yaxis_register[0] = OUT_Y_MSB; // this is the register we want to get data from
nherriot 3:ffb0b1650ca2 248 //signed short s = 0;
nherriot 3:ffb0b1650ca2 249
nherriot 3:ffb0b1650ca2 250 if(m_i2c.write(mcu_address,yaxis_register,1) == 0)
nherriot 3:ffb0b1650ca2 251 {
nherriot 3:ffb0b1650ca2 252 if(m_i2c.read(mcu_address,yaxis_buffer,2) == 0)
nherriot 3:ffb0b1650ca2 253 {
nherriot 3:ffb0b1650ca2 254 //strcpy(yaxis, yaxis_buffer);
nherriot 3:ffb0b1650ca2 255 memcpy(yaxis, yaxis_buffer, 2);
nherriot 3:ffb0b1650ca2 256 //yaxis[0] = 0x00; // make sure the array is set to zero
nherriot 3:ffb0b1650ca2 257 //yaxis[1] = 0x00;
nherriot 3:ffb0b1650ca2 258 //s = *reinterpret_cast<short*>(&xaxis);
nherriot 3:ffb0b1650ca2 259 return 0; // great we got the two octets
nherriot 3:ffb0b1650ca2 260 }
nherriot 3:ffb0b1650ca2 261 else
nherriot 3:ffb0b1650ca2 262 {
nherriot 3:ffb0b1650ca2 263 yaxis[0] = 0x00; // make sure the array is set to zero
nherriot 3:ffb0b1650ca2 264 yaxis[1] = 0x00;
nherriot 3:ffb0b1650ca2 265 return 1; // failed to read the 12 bit y value
nherriot 3:ffb0b1650ca2 266 }
nherriot 3:ffb0b1650ca2 267 }
nherriot 3:ffb0b1650ca2 268 else
nherriot 3:ffb0b1650ca2 269 {
nherriot 3:ffb0b1650ca2 270 yaxis[0] = 0x00; // make sure the array is set to zero
nherriot 3:ffb0b1650ca2 271 yaxis[1] = 0x00;
nherriot 3:ffb0b1650ca2 272 return 1; // failed to write and request the OUT_Y_MSB bit
nherriot 3:ffb0b1650ca2 273 }
nherriot 3:ffb0b1650ca2 274 }
nherriot 3:ffb0b1650ca2 275
nherriot 0:bcf2aa85d7f9 276
nherriot 3:ffb0b1650ca2 277
nherriot 3:ffb0b1650ca2 278 // Reads z data. This method reads two registers containing the x-axis values from the accelerometer.
nherriot 3:ffb0b1650ca2 279 // It takes a 2 byte char array and copies the register values into the buffer. If it fails the char array
nherriot 3:ffb0b1650ca2 280 // is set to '0'. It returns '0' success '1' fail. This method does nothing to the registers - just returns
nherriot 3:ffb0b1650ca2 281 // the raw data.
nherriot 3:ffb0b1650ca2 282
nherriot 3:ffb0b1650ca2 283 int Accelerometer_MMA8452::read_z_raw(char *zaxis)
nherriot 3:ffb0b1650ca2 284 {
nherriot 3:ffb0b1650ca2 285 char mcu_address = (MMA8452_ADDRESS<<1); // this is the slave address on the bus we want data from
nherriot 3:ffb0b1650ca2 286 char zaxis_buffer[2]; // this will contain data from that register
nherriot 3:ffb0b1650ca2 287 char zaxis_register[1];
nherriot 3:ffb0b1650ca2 288 zaxis_register[0] = OUT_Z_MSB; // this is the register we want to get data from
nherriot 3:ffb0b1650ca2 289 //signed short s = 0;
nherriot 0:bcf2aa85d7f9 290
nherriot 3:ffb0b1650ca2 291 if(m_i2c.write(mcu_address,zaxis_register,1) == 0)
nherriot 3:ffb0b1650ca2 292 {
nherriot 4:27aa3cd43234 293 //if(m_i2c.read(mcu_address,zaxis_buffer,2) == 0)
nherriot 4:27aa3cd43234 294 if(m_i2c.read(mcu_address,zaxis,2) == 0)
nherriot 3:ffb0b1650ca2 295 {
nherriot 3:ffb0b1650ca2 296 //strcpy(yaxis, yaxis_buffer);
nherriot 4:27aa3cd43234 297 //memcpy(zaxis, zaxis_buffer, 2);
nherriot 3:ffb0b1650ca2 298 //yaxis[0] = 0x00; // make sure the array is set to zero
nherriot 3:ffb0b1650ca2 299 //yaxis[1] = 0x00;
nherriot 3:ffb0b1650ca2 300 //s = *reinterpret_cast<short*>(&xaxis);
nherriot 3:ffb0b1650ca2 301 return 0; // great we got the two octets
nherriot 3:ffb0b1650ca2 302 }
nherriot 3:ffb0b1650ca2 303 else
nherriot 3:ffb0b1650ca2 304 {
nherriot 3:ffb0b1650ca2 305 zaxis[0] = 0x00; // make sure the array is set to zero
nherriot 3:ffb0b1650ca2 306 zaxis[1] = 0x00;
nherriot 3:ffb0b1650ca2 307 return 1; // failed to read the 12 bit y value
nherriot 3:ffb0b1650ca2 308 }
nherriot 3:ffb0b1650ca2 309 }
nherriot 3:ffb0b1650ca2 310 else
nherriot 3:ffb0b1650ca2 311 {
nherriot 3:ffb0b1650ca2 312 zaxis[0] = 0x00; // make sure the array is set to zero
nherriot 3:ffb0b1650ca2 313 zaxis[1] = 0x00;
nherriot 3:ffb0b1650ca2 314 return 1; // failed to write and request the OUT_Y_MSB bit
nherriot 3:ffb0b1650ca2 315 }
nherriot 3:ffb0b1650ca2 316 }
nherriot 0:bcf2aa85d7f9 317
nherriot 0:bcf2aa85d7f9 318
nherriot 0:bcf2aa85d7f9 319
nherriot 0:bcf2aa85d7f9 320 // Reads y data
nherriot 0:bcf2aa85d7f9 321 int Accelerometer_MMA8452::read_y()
nherriot 0:bcf2aa85d7f9 322 {
nherriot 1:ef026bf28798 323 char mcu_address = (MMA8452_ADDRESS <<1);
nherriot 0:bcf2aa85d7f9 324
nherriot 0:bcf2aa85d7f9 325 m_i2c.start(); // Start
nherriot 0:bcf2aa85d7f9 326 m_i2c.write(mcu_address); // A write to device 0x98
nherriot 0:bcf2aa85d7f9 327 m_i2c.write(OUT_Y_MSB); // Register to read
nherriot 0:bcf2aa85d7f9 328 m_i2c.start();
nherriot 0:bcf2aa85d7f9 329 m_i2c.write(mcu_address); // Read from device 0x99
nherriot 1:ef026bf28798 330 int y = m_i2c.read(0); // Read the data
nherriot 0:bcf2aa85d7f9 331 m_i2c.stop();
nherriot 0:bcf2aa85d7f9 332
nherriot 1:ef026bf28798 333 return y;
nherriot 0:bcf2aa85d7f9 334
nherriot 0:bcf2aa85d7f9 335 }
nherriot 0:bcf2aa85d7f9 336
nherriot 0:bcf2aa85d7f9 337
nherriot 0:bcf2aa85d7f9 338 // Reads z data
nherriot 0:bcf2aa85d7f9 339 int Accelerometer_MMA8452::read_z()
nherriot 0:bcf2aa85d7f9 340 {
nherriot 1:ef026bf28798 341 char mcu_address = (MMA8452_ADDRESS <<1);
nherriot 0:bcf2aa85d7f9 342
nherriot 0:bcf2aa85d7f9 343 m_i2c.start(); // Start
nherriot 0:bcf2aa85d7f9 344 m_i2c.write(mcu_address); // A write to device 0x98
nherriot 0:bcf2aa85d7f9 345 m_i2c.write(OUT_Z_MSB); // Register to read
nherriot 0:bcf2aa85d7f9 346 m_i2c.start();
nherriot 0:bcf2aa85d7f9 347 m_i2c.write(mcu_address); // Read from device 0x99
nherriot 1:ef026bf28798 348 int z = m_i2c.read(0); // Read the data
nherriot 0:bcf2aa85d7f9 349 m_i2c.stop();
nherriot 0:bcf2aa85d7f9 350
nherriot 1:ef026bf28798 351 return z;
nherriot 0:bcf2aa85d7f9 352
nherriot 0:bcf2aa85d7f9 353 }
nherriot 0:bcf2aa85d7f9 354
nherriot 0:bcf2aa85d7f9 355
nherriot 0:bcf2aa85d7f9 356 // Reads xyz
nherriot 1:ef026bf28798 357 int Accelerometer_MMA8452::read_xyz(char *x, char *y, char *z)
nherriot 1:ef026bf28798 358 {
nherriot 1:ef026bf28798 359
nherriot 1:ef026bf28798 360
nherriot 1:ef026bf28798 361 char mcu_address = (MMA8452_ADDRESS <<1);
nherriot 1:ef026bf28798 362 char register_buffer[6] ={0,0,0,0,0,0};
nherriot 1:ef026bf28798 363 const char Addr_X = OUT_X_MSB;
nherriot 1:ef026bf28798 364 m_i2c.write(mcu_address); // A write to device 0x98
nherriot 1:ef026bf28798 365 m_i2c.write(MMA8452_ADDRESS, &Addr_X, 1); // Pointer to the OUT_X_MSB register
nherriot 1:ef026bf28798 366
nherriot 1:ef026bf28798 367 if(m_i2c.write(mcu_address,&Addr_X,1) == 0)
nherriot 1:ef026bf28798 368 {
nherriot 1:ef026bf28798 369 if(m_i2c.read(mcu_address,register_buffer,6) == 0)
nherriot 1:ef026bf28798 370 {
nherriot 1:ef026bf28798 371 *x = register_buffer[1];
nherriot 1:ef026bf28798 372 *y = register_buffer[3];
nherriot 1:ef026bf28798 373 *z = register_buffer[5];
nherriot 1:ef026bf28798 374 return 0; // yahoooooo
nherriot 1:ef026bf28798 375 }
nherriot 1:ef026bf28798 376 else
nherriot 1:ef026bf28798 377 {
nherriot 1:ef026bf28798 378 return 1; // failed oh nooo!
nherriot 1:ef026bf28798 379 }
nherriot 1:ef026bf28798 380 }
nherriot 1:ef026bf28798 381 else
nherriot 1:ef026bf28798 382 {
nherriot 1:ef026bf28798 383 return 1; // failed oh nooo!
nherriot 1:ef026bf28798 384 }
nherriot 0:bcf2aa85d7f9 385
nherriot 1:ef026bf28798 386 }
nherriot 0:bcf2aa85d7f9 387
nherriot 0:bcf2aa85d7f9 388 // Write register (The device must be placed in Standby Mode to change the value of the registers)
nherriot 0:bcf2aa85d7f9 389 void Accelerometer_MMA8452::write_reg(char addr, char data)
nherriot 0:bcf2aa85d7f9 390 {
nherriot 0:bcf2aa85d7f9 391
nherriot 0:bcf2aa85d7f9 392 char cmd[2] = {0, 0};
nherriot 0:bcf2aa85d7f9 393
nherriot 0:bcf2aa85d7f9 394 cmd[0] = MODE_STATUS;
nherriot 0:bcf2aa85d7f9 395 cmd[1] = 0x00; // Standby Mode on
nherriot 0:bcf2aa85d7f9 396 m_i2c.write(MMA8452_ADDRESS, cmd, 2);
nherriot 0:bcf2aa85d7f9 397
nherriot 0:bcf2aa85d7f9 398 cmd[0] = addr;
nherriot 0:bcf2aa85d7f9 399 cmd[1] = data; // New value of the register
nherriot 0:bcf2aa85d7f9 400 m_i2c.write(MMA8452_ADDRESS, cmd, 2);
nherriot 0:bcf2aa85d7f9 401
nherriot 0:bcf2aa85d7f9 402 cmd[0] = MODE_STATUS;
nherriot 0:bcf2aa85d7f9 403 cmd[1] = 0x01; // Active Mode on
nherriot 0:bcf2aa85d7f9 404 m_i2c.write(MMA8452_ADDRESS, cmd, 2);
nherriot 0:bcf2aa85d7f9 405
nherriot 0:bcf2aa85d7f9 406 }
nherriot 0:bcf2aa85d7f9 407
nherriot 0:bcf2aa85d7f9 408
nherriot 0:bcf2aa85d7f9 409
nherriot 0:bcf2aa85d7f9 410 // Read from specified MMA7660FC register
nherriot 0:bcf2aa85d7f9 411 char Accelerometer_MMA8452::read_reg(char addr)
nherriot 0:bcf2aa85d7f9 412 {
nherriot 0:bcf2aa85d7f9 413
nherriot 0:bcf2aa85d7f9 414 m_i2c.start(); // Start
nherriot 0:bcf2aa85d7f9 415 m_i2c.write(0x98); // A write to device 0x98
nherriot 0:bcf2aa85d7f9 416 m_i2c.write(addr); // Register to read
nherriot 0:bcf2aa85d7f9 417 m_i2c.start();
nherriot 0:bcf2aa85d7f9 418 m_i2c.write(0x99); // Read from device 0x99
nherriot 0:bcf2aa85d7f9 419 char c = m_i2c.read(0); // Read the data
nherriot 0:bcf2aa85d7f9 420 m_i2c.stop();
nherriot 0:bcf2aa85d7f9 421
nherriot 0:bcf2aa85d7f9 422 return c;
nherriot 0:bcf2aa85d7f9 423
nherriot 0:bcf2aa85d7f9 424 }
nherriot 0:bcf2aa85d7f9 425
nherriot 0:bcf2aa85d7f9 426
nherriot 0:bcf2aa85d7f9 427
nherriot 0:bcf2aa85d7f9 428
nherriot 0:bcf2aa85d7f9 429
nherriot 0:bcf2aa85d7f9 430