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.h@5:b3d0abd97e55, 2013-10-16 (annotated)

Committer:
nherriot
Date:
Wed Oct 16 18:55:16 2013 +0000
Revision:
5:b3d0abd97e55
Parent:
3:ffb0b1650ca2 
adding method for getting control reg 1.;

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 // the SparkFun breakout board defaults to 1, set to 0 if SA0 jumper on the bottom of the board is set
nherriot 0:bcf2aa85d7f9 21 // see the Table 10. I2C Device Address Sequence in Freescale MMA8452Q pdf
nherriot 0:bcf2aa85d7f9 22
nherriot 0:bcf2aa85d7f9 23 //#define SA0 1
nherriot 0:bcf2aa85d7f9 24 //#if SA0
nherriot 0:bcf2aa85d7f9 25 //#define MMA8452_ADDRESS 0x3A // SA0 is high, 0x1C if low - it should be 0x1D, but we shift now to save shifting in the code
nherriot 0:bcf2aa85d7f9 26 //#else
nherriot 0:bcf2aa85d7f9 27 //#define MMA8452_ADDRESS 0x1C
nherriot 0:bcf2aa85d7f9 28 //#endif
nherriot 0:bcf2aa85d7f9 29
nherriot 0:bcf2aa85d7f9 30 //#ifndef MBED_MMA8452
nherriot 0:bcf2aa85d7f9 31
nherriot 0:bcf2aa85d7f9 32 //#define MBED_MMA8452
nherriot 0:bcf2aa85d7f9 33
nherriot 0:bcf2aa85d7f9 34 #include "mbed.h"
nherriot 0:bcf2aa85d7f9 35
nherriot 0:bcf2aa85d7f9 36 /** Accelerometer MMA8452 class
nherriot 0:bcf2aa85d7f9 37 *
nherriot 0:bcf2aa85d7f9 38 * Example:
nherriot 0:bcf2aa85d7f9 39 * @code
nherriot 0:bcf2aa85d7f9 40 *
nherriot 0:bcf2aa85d7f9 41 * #include "mbed.h"
nherriot 0:bcf2aa85d7f9 42 * #include "MMA8452.h"
nherriot 0:bcf2aa85d7f9 43 *
nherriot 0:bcf2aa85d7f9 44 *
nherriot 0:bcf2aa85d7f9 45 * Accelerometer_MMA8452 Acc(p28, p27);
nherriot 0:bcf2aa85d7f9 46 * serial pc(USBTX, USBRX);
nherriot 0:bcf2aa85d7f9 47 *
nherriot 0:bcf2aa85d7f9 48 * int main()
nherriot 0:bcf2aa85d7f9 49 * {
nherriot 0:bcf2aa85d7f9 50 * Acc.init();
nherriot 0:bcf2aa85d7f9 51 * while(1)
nherriot 0:bcf2aa85d7f9 52 * {
nherriot 0:bcf2aa85d7f9 53 * int x=0, y=0, z=0;
nherriot 0:bcf2aa85d7f9 54 * Acc.read_Tilt(&x, &y, &z);
nherriot 0:bcf2aa85d7f9 55 * pc.printf("Tilt x: %2.2f degree \n", x); // Print the tilt orientation of the X axis
nherriot 0:bcf2aa85d7f9 56 * pc.printf("Tilt y: %2.2f degree \n", y); // Print the tilt orientation of the Y axis
nherriot 0:bcf2aa85d7f9 57 * pc.printf("Tilt z: %2.2f degree \n", z); // Print the tilt orientation of the Z axis
nherriot 0:bcf2aa85d7f9 58 * wait(1);
nherriot 0:bcf2aa85d7f9 59 * }
nherriot 0:bcf2aa85d7f9 60 * }
nherriot 0:bcf2aa85d7f9 61 * @endcode
nherriot 0:bcf2aa85d7f9 62 */
nherriot 0:bcf2aa85d7f9 63
nherriot 0:bcf2aa85d7f9 64 // More info on MCU Master address can be found on section 5.10.1 of http://www.freescale.com/webapp/sps/site/prod_summary.jsp?code=MMA8452Q
nherriot 0:bcf2aa85d7f9 65 #define SA0 1
nherriot 0:bcf2aa85d7f9 66 #if SA0
nherriot 0:bcf2aa85d7f9 67 #define MMA8452_ADDRESS 0x1D // SA0 is high, 0x1C if low -
nherriot 0:bcf2aa85d7f9 68 #else
nherriot 0:bcf2aa85d7f9 69 #define MMA8452_ADDRESS 0x1C
nherriot 0:bcf2aa85d7f9 70 #endif
nherriot 0:bcf2aa85d7f9 71
nherriot 0:bcf2aa85d7f9 72 // Register descriptions found in section 6 of pdf
nherriot 0:bcf2aa85d7f9 73 #define STATUS 0x00 // Type 'read' : Real time status, should return 0x00
nherriot 0:bcf2aa85d7f9 74 #define OUT_X_MSB 0x01 // Type 'read' : x axis - 8 most significatn bit of a 12 bit sample
nherriot 0:bcf2aa85d7f9 75 #define OUT_X_LSB 0x02 // Type 'read' : x axis - 4 least significatn bit of a 12 bit sample
nherriot 0:bcf2aa85d7f9 76 #define OUT_Y_MSB 0x03 // Type 'read' : y axis - 8 most significatn bit of a 12 bit sample
nherriot 0:bcf2aa85d7f9 77 #define OUT_Y_LSB 0x04 // Type 'read' : y axis - 4 least significatn bit of a 12 bit sample
nherriot 0:bcf2aa85d7f9 78 #define OUT_Z_MSB 0x05 // Type 'read' : z axis - 8 most significatn bit of a 12 bit sample
nherriot 0:bcf2aa85d7f9 79 #define OUT_Z_LSB 0x06 // Type 'read' : z axis - 4 least significatn bit of a 12 bit sample
nherriot 0:bcf2aa85d7f9 80
nherriot 0:bcf2aa85d7f9 81 #define SYSMOD 0x0B // Type 'read' : This tells you if device is active, sleep or standy 0x00=STANDBY 0x01=WAKE 0x02=SLEEP
nherriot 0:bcf2aa85d7f9 82 #define WHO_AM_I 0x0D // Type 'read' : This should return the device id of 0x2A
nherriot 0:bcf2aa85d7f9 83
nherriot 0:bcf2aa85d7f9 84 #define PL_STATUS 0x10 // Type 'read' : This shows portrait landscape mode orientation
nherriot 0:bcf2aa85d7f9 85 #define PL_CFG 0x11 // Type 'read/write' : This allows portrait landscape configuration
nherriot 0:bcf2aa85d7f9 86 #define PL_COUNT 0x12 // Type 'read' : This is the portraint landscape debounce counter
nherriot 0:bcf2aa85d7f9 87 #define PL_BF_ZCOMP 0x13 // Type 'read' :
nherriot 0:bcf2aa85d7f9 88 #define PL_THS_REG 0x14 // Type 'read' :
nherriot 0:bcf2aa85d7f9 89
nherriot 0:bcf2aa85d7f9 90 #define FF_MT_CFG 0X15 // Type 'read/write' : Freefaul motion functional block configuration
nherriot 0:bcf2aa85d7f9 91 #define FF_MT_SRC 0X16 // Type 'read' : Freefaul motion event source register
nherriot 1:ef026bf28798 92 #define FF_MT_THS 0X17 // Type 'read' : Freefaul motion threshold register
nherriot 0:bcf2aa85d7f9 93 #define FF_COUNT 0X18 // Type 'read' : Freefaul motion debouce counter
nherriot 0:bcf2aa85d7f9 94
nherriot 3:ffb0b1650ca2 95 #define ASLP_COUNT 0x29 // Type 'read/write' : Counter settings for auto sleep
nherriot 0:bcf2aa85d7f9 96 #define CTRL_REG_1 0x2A // Type 'read/write' :
nherriot 0:bcf2aa85d7f9 97 #define CTRL_REG_2 0x2B // Type 'read/write' :
nherriot 0:bcf2aa85d7f9 98 #define CTRL_REG_3 0x2C // Type 'read/write' :
nherriot 0:bcf2aa85d7f9 99 #define CTRL_REG_4 0x2D // Type 'read/write' :
nherriot 0:bcf2aa85d7f9 100 #define CTRL_REG_5 0x2E // Type 'read/write' :
nherriot 0:bcf2aa85d7f9 101
nherriot 3:ffb0b1650ca2 102 // Defined in table 13 of the Freescale PDF
nherriot 3:ffb0b1650ca2 103 #define STANDBY 0x00 // State value returned after a SYSMOD request, it can be in state STANDBY, WAKE or SLEEP
nherriot 3:ffb0b1650ca2 104 #define WAKE 0x01 // State value returned after a SYSMOD request, it can be in state STANDBY, WAKE or SLEEP
nherriot 3:ffb0b1650ca2 105 #define SLEEP 0x02 // State value returned after a SYSMOD request, it can be in state STANDBY, WAKE or SLEEP
nherriot 3:ffb0b1650ca2 106 #define ACTIVE 0x01 // Stage value returned and set in Control Register 1, it can be STANDBY=00, or ACTIVE=01
nherriot 3:ffb0b1650ca2 107
nherriot 0:bcf2aa85d7f9 108
nherriot 0:bcf2aa85d7f9 109
nherriot 0:bcf2aa85d7f9 110 #define TILT_STATUS 0x03 // Tilt Status (Read only)
nherriot 0:bcf2aa85d7f9 111 #define SRST_STATUS 0x04 // Sample Rate Status Register (Read only)
nherriot 0:bcf2aa85d7f9 112 #define SPCNT_STATUS 0x05 // Sleep Count Register (Read/Write)
nherriot 0:bcf2aa85d7f9 113 #define INTSU_STATUS 0x06 // Interrupt Setup Register
nherriot 0:bcf2aa85d7f9 114 #define MODE_STATUS 0x07 // Mode Register (Read/Write)
nherriot 0:bcf2aa85d7f9 115 #define SR_STATUS 0x08 // Auto-Wake and Active Mode Portrait/Landscape Samples per Seconds Register (Read/Write)
nherriot 0:bcf2aa85d7f9 116 #define PDET_STATUS 0x09 // Tap/Pulse Detection Register (Read/Write)
nherriot 0:bcf2aa85d7f9 117 #define PD_STATUS 0xA // Tap/Pulse Debounce Count Register (Read/Write)
nherriot 0:bcf2aa85d7f9 118
nherriot 0:bcf2aa85d7f9 119
nherriot 0:bcf2aa85d7f9 120
nherriot 0:bcf2aa85d7f9 121
nherriot 0:bcf2aa85d7f9 122
nherriot 0:bcf2aa85d7f9 123
nherriot 0:bcf2aa85d7f9 124 class Accelerometer_MMA8452
nherriot 0:bcf2aa85d7f9 125 {
nherriot 0:bcf2aa85d7f9 126 public:
nherriot 0:bcf2aa85d7f9 127
nherriot 0:bcf2aa85d7f9 128
nherriot 0:bcf2aa85d7f9 129 /** Create an accelerometer object connected to the specified I2C object
nherriot 0:bcf2aa85d7f9 130 *
nherriot 0:bcf2aa85d7f9 131 * @param sda I2C data port
nherriot 0:bcf2aa85d7f9 132 * @param scl I2C8452 clock port
nherriot 0:bcf2aa85d7f9 133 *
nherriot 0:bcf2aa85d7f9 134 */
nherriot 1:ef026bf28798 135 Accelerometer_MMA8452(PinName sda, PinName scl, int frequency);
nherriot 1:ef026bf28798 136 //Accelerometer_MMA8452(PinName sda, PinName scl);
nherriot 0:bcf2aa85d7f9 137
nherriot 0:bcf2aa85d7f9 138 /** Destroys an MMA8452 object
nherriot 0:bcf2aa85d7f9 139 *
nherriot 0:bcf2aa85d7f9 140 */
nherriot 0:bcf2aa85d7f9 141 ~Accelerometer_MMA8452();
nherriot 0:bcf2aa85d7f9 142
nherriot 3:ffb0b1650ca2 143
nherriot 3:ffb0b1650ca2 144
nherriot 3:ffb0b1650ca2 145 /** Get system mode of the MMA8452 (not required)
nherriot 3:ffb0b1650ca2 146 * returns 0 for success in reading the system mode of the chip
nherriot 3:ffb0b1650ca2 147 * returns 1 for failure in reading the system mode of the chip
nherriot 3:ffb0b1650ca2 148 * -currently no retries or waiting is done, this method tries 1 time then exits.
nherriot 3:ffb0b1650ca2 149 *
nherriot 3:ffb0b1650ca2 150 * This method is used to find out the system mode of the chip ACTIVE = 0x00 or STANDBY = 0x01
nherriot 3:ffb0b1650ca2 151 */
nherriot 3:ffb0b1650ca2 152 int get_SystemMode(int& deviceSystemMode);
nherriot 3:ffb0b1650ca2 153
nherriot 3:ffb0b1650ca2 154
nherriot 3:ffb0b1650ca2 155
nherriot 3:ffb0b1650ca2 156 /** Get status of the MMA8452 (not required)
nherriot 3:ffb0b1650ca2 157 * returns 0 for success in reading the status of the chip
nherriot 3:ffb0b1650ca2 158 * returns 1 for failure in reading the status of the chip
nherriot 3:ffb0b1650ca2 159 * -currrently no retries or waiting is done, this method tries 1 time then exits.
nherriot 3:ffb0b1650ca2 160 *
nherriot 3:ffb0b1650ca2 161 * This method is used to find out the real time status of the device it shows if
nherriot 3:ffb0b1650ca2 162 * x,y and z values have been overwritten before they have been read since a change happened.
nherriot 3:ffb0b1650ca2 163 *
nherriot 3:ffb0b1650ca2 164 */
nherriot 3:ffb0b1650ca2 165 int get_Status(int& deviceStatus);
nherriot 3:ffb0b1650ca2 166
nherriot 3:ffb0b1650ca2 167
nherriot 3:ffb0b1650ca2 168
nherriot 0:bcf2aa85d7f9 169 /** Activate the MMA8452 (required)
nherriot 1:ef026bf28798 170 * returns 0 for success in activating the chip
nherriot 1:ef026bf28798 171 * returns 1 for failure in activating the chip
nherriot 1:ef026bf28798 172 * -currrently no retries or waiting is done, this method tries 1 time the exits.
nherriot 3:ffb0b1650ca2 173 *
nherriot 3:ffb0b1650ca2 174 * This will set the device 'active' even if it's already active. It's just a way to force that state.
nherriot 1:ef026bf28798 175 */
nherriot 0:bcf2aa85d7f9 176 int activate();
nherriot 3:ffb0b1650ca2 177
nherriot 3:ffb0b1650ca2 178
nherriot 3:ffb0b1650ca2 179
nherriot 3:ffb0b1650ca2 180 /** Standby the MMA8452 (not required)
nherriot 3:ffb0b1650ca2 181 * returns 0 for success in activating the chip
nherriot 3:ffb0b1650ca2 182 * returns 1 for failure in activating the chip
nherriot 3:ffb0b1650ca2 183 * -currrently no retries or waiting is done, this method tries 1 time the exits.
nherriot 3:ffb0b1650ca2 184 *
nherriot 3:ffb0b1650ca2 185 * This will set the device 'standby' even if it's already in standby. It's just a way to force that state.
nherriot 3:ffb0b1650ca2 186 */
nherriot 3:ffb0b1650ca2 187 int standby();
nherriot 3:ffb0b1650ca2 188
nherriot 3:ffb0b1650ca2 189
nherriot 5:b3d0abd97e55 190 /** get_CTRL_Reg1 the MMA8452 (not required)
nherriot 5:b3d0abd97e55 191 * returns 0 for success in activating the chip
nherriot 5:b3d0abd97e55 192 * returns 1 for failure in activating the chip
nherriot 5:b3d0abd97e55 193 * -currrently no retries or waiting is done, this method tries 1 time the exits.
nherriot 5:b3d0abd97e55 194 *
nherriot 5:b3d0abd97e55 195 * This will return the state of the control register 1. This holds and sets values for auto wake, sleep mode
nherriot 5:b3d0abd97e55 196 * output data rate, fast read mode and active/standby. More info on 6.7 of pdf for MMA8452 Freescale doc.
nherriot 5:b3d0abd97e55 197 */
nherriot 5:b3d0abd97e55 198 int get_CTRL_Reg1(int& CTRL_Reg);
nherriot 5:b3d0abd97e55 199
nherriot 0:bcf2aa85d7f9 200
nherriot 0:bcf2aa85d7f9 201 /** Initialization of device MMA8452 (required)
nherriot 0:bcf2aa85d7f9 202 */
nherriot 0:bcf2aa85d7f9 203 void init();
nherriot 0:bcf2aa85d7f9 204
nherriot 1:ef026bf28798 205 /** Read the device ID from the accelerometer
nherriot 1:ef026bf28798 206 *
nherriot 1:ef026bf28798 207 * @param *deviceID Value of device - is should be 0x2A
nherriot 1:ef026bf28798 208 * return 0 for success or
nherriot 1:ef026bf28798 209 * return 1 for failure.
nherriot 1:ef026bf28798 210 */
nherriot 3:ffb0b1650ca2 211 int get_DeviceID(int& deviceID);
nherriot 0:bcf2aa85d7f9 212
nherriot 3:ffb0b1650ca2 213 int read_y();
nherriot 3:ffb0b1650ca2 214
nherriot 3:ffb0b1650ca2 215 int read_z();
nherriot 3:ffb0b1650ca2 216
nherriot 0:bcf2aa85d7f9 217 /** Read the x register of the MMA8452
nherriot 0:bcf2aa85d7f9 218 *
nherriot 0:bcf2aa85d7f9 219 * @returns The value of x acceleration
nherriot 0:bcf2aa85d7f9 220 */
nherriot 3:ffb0b1650ca2 221 int read_x_raw(char *xaxis);
nherriot 3:ffb0b1650ca2 222 //int read_x(int& xaxisLSB);
nherriot 0:bcf2aa85d7f9 223 /** Read the y register of the MMA8452
nherriot 0:bcf2aa85d7f9 224 *
nherriot 0:bcf2aa85d7f9 225 * @returns The value of y acceleration
nherriot 0:bcf2aa85d7f9 226 */
nherriot 3:ffb0b1650ca2 227 int read_y_raw(char *yaxis);
nherriot 0:bcf2aa85d7f9 228
nherriot 0:bcf2aa85d7f9 229 /** Read the z register of the MMA8452
nherriot 0:bcf2aa85d7f9 230 *
nherriot 0:bcf2aa85d7f9 231 * @returns The value of z acceleration
nherriot 0:bcf2aa85d7f9 232 */
nherriot 3:ffb0b1650ca2 233 int read_z_raw(char * zaxis);
nherriot 1:ef026bf28798 234
nherriot 1:ef026bf28798 235 /** Read the x,y and z registers of the MMA8452
nherriot 1:ef026bf28798 236 *
nherriot 1:ef026bf28798 237 * takes a 2 byte char buffer to store the value
nherriot 1:ef026bf28798 238 * for each axis.
nherriot 1:ef026bf28798 239 * returns 0 for success, and 1 for failure
nherriot 1:ef026bf28798 240 *
nherriot 1:ef026bf28798 241 */
nherriot 1:ef026bf28798 242 int read_xyz(char *x, char *y, char *z);
nherriot 0:bcf2aa85d7f9 243
nherriot 0:bcf2aa85d7f9 244 /** Read from specified MMA8452 register
nherriot 0:bcf2aa85d7f9 245 *
nherriot 0:bcf2aa85d7f9 246 * @param addr The internal registeraddress of the MMA8452
nherriot 0:bcf2aa85d7f9 247 * @returns The value of the register
nherriot 0:bcf2aa85d7f9 248 */
nherriot 0:bcf2aa85d7f9 249 char read_reg(char addr);
nherriot 0:bcf2aa85d7f9 250
nherriot 0:bcf2aa85d7f9 251 /** Write to specified MMA8452 register
nherriot 0:bcf2aa85d7f9 252 *
nherriot 0:bcf2aa85d7f9 253 * @param addr The internal registeraddress of the MMA8452
nherriot 0:bcf2aa85d7f9 254 * @param data New value of the register
nherriot 0:bcf2aa85d7f9 255 */
nherriot 0:bcf2aa85d7f9 256 void write_reg(char addr, char data);
nherriot 0:bcf2aa85d7f9 257
nherriot 0:bcf2aa85d7f9 258
nherriot 0:bcf2aa85d7f9 259 private:
nherriot 0:bcf2aa85d7f9 260 I2C m_i2c;
nherriot 1:ef026bf28798 261 int m_frequency;
nherriot 0:bcf2aa85d7f9 262
nherriot 0:bcf2aa85d7f9 263 };
nherriot 0:bcf2aa85d7f9 264
nherriot 0:bcf2aa85d7f9 265 //#endif