Allows for reading accelerometer, gyroscope, and magnetometer data from an LSM9DS0 IMU device

Dependencies:   mbed

Dependents:   uVGA_4180 uLCD_4180_mini ECE4781_Project

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Show/hide line numbers I2Cdev.cpp Source File

I2Cdev.cpp

00001 // ported from arduino library: https://github.com/jrowberg/i2cdevlib
00002 // written by szymon gaertig (email: szymon@gaertig.com.pl, website: szymongaertig.pl)
00003 // Changelog:
00004 // 2013-01-08 - first release
00005 
00006 #include "I2Cdev.h"
00007 
00008 #define useDebugSerial
00009 
00010 I2Cdev::I2Cdev(): i2c(I2C_SDA,I2C_SCL), debugSerial(USBTX, USBRX)
00011 {
00012 
00013 }
00014 
00015 I2Cdev::I2Cdev(PinName i2cSda, PinName i2cScl): i2c(i2cSda,i2cScl), debugSerial(USBTX, USBRX)
00016 {
00017       i2c.frequency(100000);
00018 }
00019 
00020 /** Read a single bit from an 8-bit device register.
00021  * @param devAddr I2C slave device address
00022  * @param regAddr Register regAddr to read from
00023  * @param bitNum Bit position to read (0-7)
00024  * @param data Container for single bit value
00025  * @param timeout Optional read timeout in milliseconds (0 to disable, leave off to use default class value in I2Cdev::readTimeout)
00026  * @return Status of read operation (true = success)
00027  */
00028 int8_t I2Cdev::readBit(uint8_t devAddr, uint8_t regAddr, uint8_t bitNum, uint8_t *data, uint16_t timeout) {
00029     uint8_t b;
00030     uint8_t count = readByte(devAddr, regAddr, &b, timeout);
00031     *data = b & (1 << bitNum);
00032     return count;
00033 }
00034 
00035 /** Read a single bit from a 16-bit device register.
00036  * @param devAddr I2C slave device address
00037  * @param regAddr Register regAddr to read from
00038  * @param bitNum Bit position to read (0-15)
00039  * @param data Container for single bit value
00040  * @param timeout Optional read timeout in milliseconds (0 to disable, leave off to use default class value in I2Cdev::readTimeout)
00041  * @return Status of read operation (true = success)
00042  */
00043 int8_t I2Cdev::readBitW(uint8_t devAddr, uint8_t regAddr, uint8_t bitNum, uint16_t *data, uint16_t timeout) {
00044     uint16_t b;
00045     uint8_t count = readWord(devAddr, regAddr, &b, timeout);
00046     *data = b & (1 << bitNum);
00047     return count;
00048 }
00049 
00050 /** Read multiple bits from an 8-bit device register.
00051  * @param devAddr I2C slave device address
00052  * @param regAddr Register regAddr to read from
00053  * @param bitStart First bit position to read (0-7)
00054  * @param length Number of bits to read (not more than 8)
00055  * @param data Container for right-aligned value (i.e. '101' read from any bitStart position will equal 0x05)
00056  * @param timeout Optional read timeout in milliseconds (0 to disable, leave off to use default class value in I2Cdev::readTimeout)
00057  * @return Status of read operation (true = success)
00058  */
00059 int8_t I2Cdev::readBits(uint8_t devAddr, uint8_t regAddr, uint8_t bitStart, uint8_t length, uint8_t *data, uint16_t timeout) {
00060     // 01101001 read byte
00061     // 76543210 bit numbers
00062     //    xxx   args: bitStart=4, length=3
00063     //    010   masked
00064     //   -> 010 shifted
00065     uint8_t count, b;
00066     if ((count = readByte(devAddr, regAddr, &b, timeout)) != 0) {
00067         uint8_t mask = ((1 << length) - 1) << (bitStart - length + 1);
00068         b &= mask;
00069         b >>= (bitStart - length + 1);
00070         *data = b;
00071     }
00072     return count;
00073 }
00074 
00075 /** Read multiple bits from a 16-bit device register.
00076  * @param devAddr I2C slave device address
00077  * @param regAddr Register regAddr to read from
00078  * @param bitStart First bit position to read (0-15)
00079  * @param length Number of bits to read (not more than 16)
00080  * @param data Container for right-aligned value (i.e. '101' read from any bitStart position will equal 0x05)
00081  * @param timeout Optional read timeout in milliseconds (0 to disable, leave off to use default class value in I2Cdev::readTimeout)
00082  * @return Status of read operation (1 = success, 0 = failure, -1 = timeout)
00083  */
00084 int8_t I2Cdev::readBitsW(uint8_t devAddr, uint8_t regAddr, uint8_t bitStart, uint8_t length, uint16_t *data, uint16_t timeout) {
00085     // 1101011001101001 read byte
00086     // fedcba9876543210 bit numbers
00087     //    xxx           args: bitStart=12, length=3
00088     //    010           masked
00089     //           -> 010 shifted
00090     uint8_t count;
00091     uint16_t w;
00092     if ((count = readWord(devAddr, regAddr, &w, timeout)) != 0) {
00093         uint16_t mask = ((1 << length) - 1) << (bitStart - length + 1);
00094         w &= mask;
00095         w >>= (bitStart - length + 1);
00096         *data = w;
00097     }
00098     return count;
00099 }
00100 /** Read single byte from an 8-bit device register.
00101  * @param devAddr I2C slave device address
00102  * @param regAddr Register regAddr to read from
00103  * @param data Container for byte value read from device
00104  * @param timeout Optional read timeout in milliseconds (0 to disable, leave off to use default class value in I2Cdev::readTimeout)
00105  * @return Status of read operation (true = success)
00106  */
00107 int8_t I2Cdev::readByte(uint8_t devAddr, uint8_t regAddr, uint8_t *data, uint16_t timeout) {
00108     
00109     return readBytes(devAddr, regAddr, 1, data, timeout);
00110 }
00111 
00112 /** Read single word from a 16-bit device register.
00113  * @param devAddr I2C slave device address
00114  * @param regAddr Register regAddr to read from
00115  * @param data Container for word value read from device
00116  * @param timeout Optional read timeout in milliseconds (0 to disable, leave off to use default class value in I2Cdev::readTimeout)
00117  * @return Status of read operation (true = success)
00118  */
00119 int8_t I2Cdev::readWord(uint8_t devAddr, uint8_t regAddr, uint16_t *data, uint16_t timeout) {
00120     return readWords(devAddr, regAddr, 1, data, timeout);
00121 }
00122 
00123 /** Read multiple bytes from an 8-bit device register.
00124  * @param devAddr I2C slave device address
00125  * @param regAddr First register regAddr to read from
00126  * @param length Number of bytes to read
00127  * @param data Buffer to store read data in
00128  * @param timeout Optional read timeout in milliseconds (0 to disable, leave off to use default class value in I2Cdev::readTimeout)
00129  * @return Number of bytes read (-1 indicates failure)
00130  */
00131 int8_t I2Cdev::readBytes(uint8_t devAddr, uint8_t regAddr, uint8_t length, uint8_t *data, uint16_t timeout)
00132 {
00133     char command[1];
00134     command[0] = regAddr;
00135     char *redData = (char*)malloc(length);
00136     i2c.write(devAddr<<1, command, 1, true);
00137     i2c.read(devAddr<<1, redData, length);
00138     for(int i =0; i < length; i++) {
00139         data[i] = redData[i];
00140         //debugSerial.printf("We read %x\n" , redData[i]);
00141 
00142     }
00143     free (redData);
00144     return length;
00145 }
00146 
00147 int8_t I2Cdev::readWords(uint8_t devAddr, uint8_t regAddr, uint8_t length, uint16_t *data, uint16_t timeout)
00148 {
00149     return 0;
00150 }
00151 
00152 /** write a single bit in an 8-bit device register.
00153  * @param devAddr I2C slave device address
00154  * @param regAddr Register regAddr to write to
00155  * @param bitNum Bit position to write (0-7)
00156  * @param value New bit value to write
00157  * @return Status of operation (true = success)
00158  */
00159 bool I2Cdev::writeBit(uint8_t devAddr, uint8_t regAddr, uint8_t bitNum, uint8_t data) {
00160     uint8_t b;
00161     readByte(devAddr, regAddr, &b);
00162     b = (data != 0) ? (b | (1 << bitNum)) : (b & ~(1 << bitNum));
00163     return writeByte(devAddr, regAddr, b);
00164 }
00165 
00166 /** write a single bit in a 16-bit device register.
00167  * @param devAddr I2C slave device address
00168  * @param regAddr Register regAddr to write to
00169  * @param bitNum Bit position to write (0-15)
00170  * @param value New bit value to write
00171  * @return Status of operation (true = success)
00172  */
00173 bool I2Cdev::writeBitW(uint8_t devAddr, uint8_t regAddr, uint8_t bitNum, uint16_t data) {
00174     uint16_t w;
00175     readWord(devAddr, regAddr, &w);
00176     w = (data != 0) ? (w | (1 << bitNum)) : (w & ~(1 << bitNum));
00177     return writeWord(devAddr, regAddr, w);
00178 }
00179 
00180 /** Write multiple bits in an 8-bit device register.
00181  * @param devAddr I2C slave device address
00182  * @param regAddr Register regAddr to write to
00183  * @param bitStart First bit position to write (0-7)
00184  * @param length Number of bits to write (not more than 8)
00185  * @param data Right-aligned value to write
00186  * @return Status of operation (true = success)
00187  */
00188 bool I2Cdev::writeBits(uint8_t devAddr, uint8_t regAddr, uint8_t bitStart, uint8_t length, uint8_t data) {
00189     //      010 value to write
00190     // 76543210 bit numbers
00191     //    xxx   args: bitStart=4, length=3
00192     // 00011100 mask byte
00193     // 10101111 original value (sample)
00194     // 10100011 original & ~mask
00195     // 10101011 masked | value
00196     uint8_t b;
00197     if (readByte(devAddr, regAddr, &b) != 0) {
00198         uint8_t mask = ((1 << length) - 1) << (bitStart - length + 1);
00199         data <<= (bitStart - length + 1); // shift data into correct position
00200         data &= mask; // zero all non-important bits in data
00201         b &= ~(mask); // zero all important bits in existing byte
00202         b |= data; // combine data with existing byte
00203         return writeByte(devAddr, regAddr, b);
00204     } else {
00205         return false;
00206     }
00207 }
00208 
00209 /** Write multiple bits in a 16-bit device register.
00210  * @param devAddr I2C slave device address
00211  * @param regAddr Register regAddr to write to
00212  * @param bitStart First bit position to write (0-15)
00213  * @param length Number of bits to write (not more than 16)
00214  * @param data Right-aligned value to write
00215  * @return Status of operation (true = success)
00216  */
00217 bool I2Cdev::writeBitsW(uint8_t devAddr, uint8_t regAddr, uint8_t bitStart, uint8_t length, uint16_t data) {
00218     //              010 value to write
00219     // fedcba9876543210 bit numbers
00220     //    xxx           args: bitStart=12, length=3
00221     // 0001110000000000 mask byte
00222     // 1010111110010110 original value (sample)
00223     // 1010001110010110 original & ~mask
00224     // 1010101110010110 masked | value
00225     uint16_t w;
00226     if (readWord(devAddr, regAddr, &w) != 0) {
00227         uint8_t mask = ((1 << length) - 1) << (bitStart - length + 1);
00228         data <<= (bitStart - length + 1); // shift data into correct position
00229         data &= mask; // zero all non-important bits in data
00230         w &= ~(mask); // zero all important bits in existing word
00231         w |= data; // combine data with existing word
00232         return writeWord(devAddr, regAddr, w);
00233     } else {
00234         return false;
00235     }
00236 }
00237 
00238 /** Write single byte to an 8-bit device register.
00239  * @param devAddr I2C slave device address
00240  * @param regAddr Register address to write to
00241  * @param data New byte value to write
00242  * @return Status of operation (true = success)
00243  */
00244 bool I2Cdev::writeByte(uint8_t devAddr, uint8_t regAddr, uint8_t data) {
00245     return writeBytes(devAddr, regAddr, 1, &data);
00246 }
00247 
00248 /** Write single word to a 16-bit device register.
00249  * @param devAddr I2C slave device address
00250  * @param regAddr Register address to write to
00251  * @param data New word value to write
00252  * @return Status of operation (true = success)
00253  */
00254 bool I2Cdev::writeWord(uint8_t devAddr, uint8_t regAddr, uint16_t data) {
00255     return writeWords(devAddr, regAddr, 1, &data);
00256 }
00257 
00258 bool I2Cdev::writeBytes(uint8_t devAddr, uint8_t regAddr, uint8_t length, uint8_t *data)
00259 {
00260     i2c.start();
00261     i2c.write(devAddr<<1);
00262     i2c.write(regAddr);
00263     for(int i = 0; i < length; i++) {
00264         i2c.write(data[i]);
00265     }
00266     i2c.stop();
00267     return true;
00268 }
00269 
00270 bool I2Cdev::writeWords(uint8_t devAddr, uint8_t regAddr, uint8_t length, uint16_t *data)
00271 {
00272     return true;
00273 }
00274 
00275 uint16_t I2Cdev::readTimeout(void)
00276 {
00277     return 0;
00278 }