// I2Cdev library collection - Main I2C device class
// Abstracts bit and byte I2C R/W functions into a convenient class
// 11/1/2011 by Jeff Rowberg <jeff@rowberg.net>
//
// Changelog:
// 2011-11-01 - fix write*Bits mask calculation (thanks sasquatch @ Arduino forums)
// 2011-10-03 - added automatic Arduino version detection for ease of use
// 2011-10-02 - added Gene Knight's NBWire TwoWire class implementation with small modifications
// 2011-08-31 - added support for Arduino 1.0 Wire library (methods are different from 0.x)
// 2011-08-03 - added optional timeout parameter to read* methods to easily change from default
// 2011-08-02 - added support for 16-bit registers
// - fixed incorrect Doxygen comments on some methods
// - added timeout value for read operations (thanks mem @ Arduino forums)
// 2011-07-30 - changed read/write function structures to return success or byte counts
// - made all methods static for multi-device memory savings
// 2011-07-28 - initial release
/* ============================================
I2Cdev device library code is placed under the MIT license
Copyright (c) 2011 Jeff Rowberg
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.
===============================================
*/
#include "I2Cdev.h"
#if I2CDEV_IMPLEMENTATION == I2CDEV_BUILTIN_NBWIRE
// NBWire implementation based heavily on code by Gene Knight <Gene@Telobot.com>
// Originally posted on the Arduino forum at http://arduino.cc/forum/index.php/topic,70705.0.html
// Originally offered to the i2cdevlib project at http://arduino.cc/forum/index.php/topic,68210.30.html
TwoWire Wire;
#endif
/** Default constructor.
*/
I2Cdev::I2Cdev() {
}
/** Read a single bit from an 8-bit device register.
* @param devAddr I2C slave device address
* @param regAddr Register regAddr to read from
* @param bitNum Bit position to read (0-7)
* @param data Container for single bit value
* @param timeout Optional read timeout in milliseconds (0 to disable, leave off to use default class value in I2Cdev::readTimeout)
* @return Status of read operation (true = success)
*/
int8_t I2Cdev::readBit(uint8_t devAddr, uint8_t regAddr, uint8_t bitNum, uint8_t *data, uint16_t timeout) {
uint8_t b;
uint8_t count = readByte(devAddr, regAddr, &b, timeout);
*data = b & (1 << bitNum);
return count;
}
/** Read a single bit from a 16-bit device register.
* @param devAddr I2C slave device address
* @param regAddr Register regAddr to read from
* @param bitNum Bit position to read (0-15)
* @param data Container for single bit value
* @param timeout Optional read timeout in milliseconds (0 to disable, leave off to use default class value in I2Cdev::readTimeout)
* @return Status of read operation (true = success)
*/
int8_t I2Cdev::readBitW(uint8_t devAddr, uint8_t regAddr, uint8_t bitNum, uint16_t *data, uint16_t timeout) {
uint16_t b;
uint8_t count = readWord(devAddr, regAddr, &b, timeout);
*data = b & (1 << bitNum);
return count;
}
/** Read multiple bits from an 8-bit device register.
* @param devAddr I2C slave device address
* @param regAddr Register regAddr to read from
* @param bitStart First bit position to read (0-7)
* @param length Number of bits to read (not more than 8)
* @param data Container for right-aligned value (i.e. '101' read from any bitStart position will equal 0x05)
* @param timeout Optional read timeout in milliseconds (0 to disable, leave off to use default class value in I2Cdev::readTimeout)
* @return Status of read operation (true = success)
*/
int8_t I2Cdev::readBits(uint8_t devAddr, uint8_t regAddr, uint8_t bitStart, uint8_t length, uint8_t *data, uint16_t timeout) {
// 01101001 read byte
// 76543210 bit numbers
// xxx args: bitStart=4, length=3
// 010 masked
// -> 010 shifted
uint8_t count, b;
if ((count = readByte(devAddr, regAddr, &b, timeout)) != 0) {
uint8_t mask = ((1 << length) - 1) << (bitStart - length + 1);
b &= mask;
b >>= (bitStart - length + 1);
*data = b;
}
return count;
}
/** Read multiple bits from a 16-bit device register.
* @param devAddr I2C slave device address
* @param regAddr Register regAddr to read from
* @param bitStart First bit position to read (0-15)
* @param length Number of bits to read (not more than 16)
* @param data Container for right-aligned value (i.e. '101' read from any bitStart position will equal 0x05)
* @param timeout Optional read timeout in milliseconds (0 to disable, leave off to use default class value in I2Cdev::readTimeout)
* @return Status of read operation (1 = success, 0 = failure, -1 = timeout)
*/
int8_t I2Cdev::readBitsW(uint8_t devAddr, uint8_t regAddr, uint8_t bitStart, uint8_t length, uint16_t *data, uint16_t timeout) {
// 1101011001101001 read byte
// fedcba9876543210 bit numbers
// xxx args: bitStart=12, length=3
// 010 masked
// -> 010 shifted
uint8_t count;
uint16_t w;
if ((count = readWord(devAddr, regAddr, &w, timeout)) != 0) {
uint16_t mask = ((1 << length) - 1) << (bitStart - length + 1);
w &= mask;
w >>= (bitStart - length + 1);
*data = w;
}
return count;
}
/** Read single byte from an 8-bit device register.
* @param devAddr I2C slave device address
* @param regAddr Register regAddr to read from
* @param data Container for byte value read from device
* @param timeout Optional read timeout in milliseconds (0 to disable, leave off to use default class value in I2Cdev::readTimeout)
* @return Status of read operation (true = success)
*/
int8_t I2Cdev::readByte(uint8_t devAddr, uint8_t regAddr, uint8_t *data, uint16_t timeout) {
return readBytes(devAddr, regAddr, 1, data, timeout);
}
/** Read single word from a 16-bit device register.
* @param devAddr I2C slave device address
* @param regAddr Register regAddr to read from
* @param data Container for word value read from device
* @param timeout Optional read timeout in milliseconds (0 to disable, leave off to use default class value in I2Cdev::readTimeout)
* @return Status of read operation (true = success)
*/
int8_t I2Cdev::readWord(uint8_t devAddr, uint8_t regAddr, uint16_t *data, uint16_t timeout) {
return readWords(devAddr, regAddr, 1, data, timeout);
}
/** Read multiple bytes from an 8-bit device register.
* @param devAddr I2C slave device address
* @param regAddr First register regAddr to read from
* @param length Number of bytes to read
* @param data Buffer to store read data in
* @param timeout Optional read timeout in milliseconds (0 to disable, leave off to use default class value in I2Cdev::readTimeout)
* @return Number of bytes read (0 indicates failure)
*/
int8_t I2Cdev
