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(p26,p27)//PB9,PB8   //D14,D15
00011 {
00012 
00013 }
00014 
00015 I2Cdev::I2Cdev(PinName p26, PinName p27): i2c(p26,p27)
00016 {
00017 
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 void I2Cdev::frequency(uint8_t freq){
00050     i2c.frequency(freq);
00051     }
00052 /** Read multiple bits from an 8-bit device register.
00053  * @param devAddr I2C slave device address
00054  * @param regAddr Register regAddr to read from
00055  * @param bitStart First bit position to read (0-7)
00056  * @param length Number of bits to read (not more than 8)
00057  * @param data Container for right-aligned value (i.e. '101' read from any bitStart position will equal 0x05)
00058  * @param timeout Optional read timeout in milliseconds (0 to disable, leave off to use default class value in I2Cdev::readTimeout)
00059  * @return Status of read operation (true = success)
00060  */
00061 int8_t I2Cdev::readBits(uint8_t devAddr, uint8_t regAddr, uint8_t bitStart, uint8_t length, uint8_t *data, uint16_t timeout) {
00062     // 01101001 read byte
00063     // 76543210 bit numbers
00064     //    xxx   args: bitStart=4, length=3
00065     //    010   masked
00066     //   -> 010 shifted
00067     uint8_t count, b;
00068     if ((count = readByte(devAddr, regAddr, &b, timeout)) != 0) {
00069         uint8_t mask = ((1 << length) - 1) << (bitStart - length + 1);
00070         b &= mask;
00071         b >>= (bitStart - length + 1);
00072         *data = b;
00073     }
00074     return count;
00075 }
00076 
00077 /** Read multiple bits from a 16-bit device register.
00078  * @param devAddr I2C slave device address
00079  * @param regAddr Register regAddr to read from
00080  * @param bitStart First bit position to read (0-15)
00081  * @param length Number of bits to read (not more than 16)
00082  * @param data Container for right-aligned value (i.e. '101' read from any bitStart position will equal 0x05)
00083  * @param timeout Optional read timeout in milliseconds (0 to disable, leave off to use default class value in I2Cdev::readTimeout)
00084  * @return Status of read operation (1 = success, 0 = failure, -1 = timeout)
00085  */
00086 int8_t I2Cdev::readBitsW(uint8_t devAddr, uint8_t regAddr, uint8_t bitStart, uint8_t length, uint16_t *data, uint16_t timeout) {
00087     // 1101011001101001 read byte
00088     // fedcba9876543210 bit numbers
00089     //    xxx           args: bitStart=12, length=3
00090     //    010           masked
00091     //           -> 010 shifted
00092     uint8_t count;
00093     uint16_t w;
00094     if ((count = readWord(devAddr, regAddr, &w, timeout)) != 0) {
00095         uint16_t mask = ((1 << length) - 1) << (bitStart - length + 1);
00096         w &= mask;
00097         w >>= (bitStart - length + 1);
00098         *data = w;
00099     }
00100     return count;
00101 }
00102 /** Read single byte from an 8-bit device register.
00103  * @param devAddr I2C slave device address
00104  * @param regAddr Register regAddr to read from
00105  * @param data Container for byte value read from device
00106  * @param timeout Optional read timeout in milliseconds (0 to disable, leave off to use default class value in I2Cdev::readTimeout)
00107  * @return Status of read operation (true = success)
00108  */
00109 int8_t I2Cdev::readByte(uint8_t devAddr, uint8_t regAddr, uint8_t *data, uint16_t timeout) {
00110     return readBytes(devAddr, regAddr, 1, data, timeout);
00111 }
00112 
00113 /** Read single word from a 16-bit device register.
00114  * @param devAddr I2C slave device address
00115  * @param regAddr Register regAddr to read from
00116  * @param data Container for word value read from device
00117  * @param timeout Optional read timeout in milliseconds (0 to disable, leave off to use default class value in I2Cdev::readTimeout)
00118  * @return Status of read operation (true = success)
00119  */
00120 int8_t I2Cdev::readWord(uint8_t devAddr, uint8_t regAddr, uint16_t *data, uint16_t timeout) {
00121     return readWords(devAddr, regAddr, 1, data, timeout);
00122 }
00123 
00124 /** Read multiple bytes from an 8-bit device register.
00125  * @param devAddr I2C slave device address
00126  * @param regAddr First register regAddr to read from
00127  * @param length Number of bytes to read
00128  * @param data Buffer to store read data in
00129  * @param timeout Optional read timeout in milliseconds (0 to disable, leave off to use default class value in I2Cdev::readTimeout)
00130  * @return Number of bytes read (-1 indicates failure)
00131  */
00132 int8_t I2Cdev::readBytes(uint8_t devAddr, uint8_t regAddr, uint8_t length, uint8_t *data, uint16_t timeout)
00133 {
00134     char command[1];
00135     command[0] = regAddr;
00136     char *redData = (char*)malloc(length);
00137     i2c.write(devAddr<<1, command, 1, true);
00138     i2c.read(devAddr<<1, redData, length);
00139     for(int i =0; i < length; i++) {
00140         data[i] = redData[i];
00141     }
00142     free (redData);
00143     return length;
00144 }
00145 
00146 int8_t I2Cdev::readWords(uint8_t devAddr, uint8_t regAddr, uint8_t length, uint16_t *data, uint16_t timeout)
00147 {
00148     return 0;
00149 }
00150 
00151 /** write a single bit in an 8-bit device register.
00152  * @param devAddr I2C slave device address
00153  * @param regAddr Register regAddr to write to
00154  * @param bitNum Bit position to write (0-7)
00155  * @param value New bit value to write
00156  * @return Status of operation (true = success)
00157  */
00158 bool I2Cdev::writeBit(uint8_t devAddr, uint8_t regAddr, uint8_t bitNum, uint8_t data) {
00159     uint8_t b;
00160     readByte(devAddr, regAddr, &b);
00161     b = (data != 0) ? (b | (1 << bitNum)) : (b & ~(1 << bitNum));
00162     return writeByte(devAddr, regAddr, b);
00163 }
00164 
00165 /** write a single bit in a 16-bit device register.
00166  * @param devAddr I2C slave device address
00167  * @param regAddr Register regAddr to write to
00168  * @param bitNum Bit position to write (0-15)
00169  * @param value New bit value to write
00170  * @return Status of operation (true = success)
00171  */
00172 bool I2Cdev::writeBitW(uint8_t devAddr, uint8_t regAddr, uint8_t bitNum, uint16_t data) {
00173     uint16_t w;
00174     readWord(devAddr, regAddr, &w);
00175     w = (data != 0) ? (w | (1 << bitNum)) : (w & ~(1 << bitNum));
00176     return writeWord(devAddr, regAddr, w);
00177 }
00178 
00179 /** Write multiple bits in an 8-bit device register.
00180  * @param devAddr I2C slave device address
00181  * @param regAddr Register regAddr to write to
00182  * @param bitStart First bit position to write (0-7)
00183  * @param length Number of bits to write (not more than 8)
00184  * @param data Right-aligned value to write
00185  * @return Status of operation (true = success)
00186  */
00187 bool I2Cdev::writeBits(uint8_t devAddr, uint8_t regAddr, uint8_t bitStart, uint8_t length, uint8_t data) {
00188     //      010 value to write
00189     // 76543210 bit numbers
00190     //    xxx   args: bitStart=4, length=3
00191     // 00011100 mask byte
00192     // 10101111 original value (sample)
00193     // 10100011 original & ~mask
00194     // 10101011 masked | value
00195     uint8_t b;
00196     if (readByte(devAddr, regAddr, &b) != 0) {
00197         uint8_t mask = ((1 << length) - 1) << (bitStart - length + 1);
00198         data <<= (bitStart - length + 1); // shift data into correct position
00199         data &= mask; // zero all non-important bits in data
00200         b &= ~(mask); // zero all important bits in existing byte
00201         b |= data; // combine data with existing byte
00202         return writeByte(devAddr, regAddr, b);
00203     } else {
00204         return false;
00205     }
00206 }
00207 
00208 /** Write multiple bits in a 16-bit device register.
00209  * @param devAddr I2C slave device address
00210  * @param regAddr Register regAddr to write to
00211  * @param bitStart First bit position to write (0-15)
00212  * @param length Number of bits to write (not more than 16)
00213  * @param data Right-aligned value to write
00214  * @return Status of operation (true = success)
00215  */
00216 bool I2Cdev::writeBitsW(uint8_t devAddr, uint8_t regAddr, uint8_t bitStart, uint8_t length, uint16_t data) {
00217     //              010 value to write
00218     // fedcba9876543210 bit numbers
00219     //    xxx           args: bitStart=12, length=3
00220     // 0001110000000000 mask byte
00221     // 1010111110010110 original value (sample)
00222     // 1010001110010110 original & ~mask
00223     // 1010101110010110 masked | value
00224     uint16_t w;
00225     if (readWord(devAddr, regAddr, &w) != 0) {
00226         uint8_t mask = ((1 << length) - 1) << (bitStart - length + 1);
00227         data <<= (bitStart - length + 1); // shift data into correct position
00228         data &= mask; // zero all non-important bits in data
00229         w &= ~(mask); // zero all important bits in existing word
00230         w |= data; // combine data with existing word
00231         return writeWord(devAddr, regAddr, w);
00232     } else {
00233         return false;
00234     }
00235 }
00236 
00237 /** Write single byte to an 8-bit device register.
00238  * @param devAddr I2C slave device address
00239  * @param regAddr Register address to write to
00240  * @param data New byte value to write
00241  * @return Status of operation (true = success)
00242  */
00243 bool I2Cdev::writeByte(uint8_t devAddr, uint8_t regAddr, uint8_t data) {
00244     devAddr=0xd0;
00245     //pc.printf("| Address: %x | Register: %x \r\n",devAddr,regAddr);
00246  
00247     char data_write[2];
00248     data_write[0]=regAddr;           // I2C sends MSB first. Namely  >>|subAddress|>>|data|
00249     data_write[1]=data;
00250     i2c.write(devAddr,data_write,2,0);  // i2c.write(int address, char* data, int length, bool repeated=false);  
00251     return writeBytes(devAddr, regAddr, 1, &data);
00252     return true;
00253 }
00254 
00255 /** Write single word to a 16-bit device register.
00256  * @param devAddr I2C slave device address
00257  * @param regAddr Register address to write to
00258  * @param data New word value to write
00259  * @return Status of operation (true = success)
00260  */
00261 bool I2Cdev::writeWord(uint8_t devAddr, uint8_t regAddr, uint16_t data) {
00262     return writeWords(devAddr, regAddr, 1, &data);
00263 }
00264 
00265 bool I2Cdev::writeBytes(uint8_t devAddr, uint8_t regAddr, uint8_t length, uint8_t *data)
00266 {
00267     i2c.start();
00268     i2c.write(devAddr<<1);
00269     i2c.write(regAddr);
00270     for(int i = 0; i < length; i++) {
00271         i2c.write(data[i]);
00272     }
00273     //i2c.write(devAddr, regAddr, )
00274     i2c.stop();
00275     return true;
00276 }
00277 
00278 bool I2Cdev::writeWords(uint8_t devAddr, uint8_t regAddr, uint8_t length, uint16_t *data)
00279 {
00280     return true;
00281 }
00282 
00283 uint16_t I2Cdev::readTimeout(void)
00284 {
00285     return 0;
00286 }