lib for working with ltc2991s
Fork of ltc2991_test by
LT_I2C.cpp
- Committer:
- lrdawg99
- Date:
- 2016-12-06
- Revision:
- 2:c9e727dcd00e
- Parent:
- 1:4e4194db7cd6
- Child:
- 8:c0ae66611a12
File content as of revision 2:c9e727dcd00e:
/*! LT_I2C: Routines to communicate with ATmega328P's hardware I2C port. @verbatim LT_I2C contains the low level routines to communicate with devices using the ATMega328's onboard hardware I2C port. Each routine checks the Two Wire Status Register (TWSR) at the end of the transaction and returns 0 if successful and 1 if not successful. I2C Frequency = (CPU Clock frequency)/(16+2(TWBR)*Prescaler) TWBR-Two Wire Bit Rate Register TWCR=Two Wire Control Register (TWINT TWEA TWSTA TWSTO TWWC TWEN - TWIE) TWSR=Two Wire Status Register Prescaler Values: TWSR1 TWSR0 Prescaler 0 0 1 0 1 4 1 0 16 1 1 64 Examples: CPU Frequency = 16Mhz on Arduino Uno I2C Frequency Prescaler TWSR1 TWSR0 TWBR 1khz 64 1 1 125 10khz 64 1 1 12 50khz 16 1 0 10 100khz 4 0 1 18 400khz 1 0 0 12 @endverbatim REVISION HISTORY $Revision: 5469 $ $Date: 2016-07-22 17:01:32 -0700 (Fri, 22 Jul 2016) $ Copyright (c) 2013, Linear Technology Corp.(LTC) All rights reserved. Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met: 1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer. 2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution. THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. The views and conclusions contained in the software and documentation are those of the authors and should not be interpreted as representing official policies, either expressed or implied, of Linear Technology Corp. The Linear Technology Linduino is not affiliated with the official Arduino team. However, the Linduino is only possible because of the Arduino team's commitment to the open-source community. Please, visit http://www.arduino.cc and http://store.arduino.cc , and consider a purchase that will help fund their ongoing work. */ //! @defgroup LT_I2C LT_I2C: Routines to Communicate With ATmega328P's hardware I2C port. /*! @file @ingroup LT_I2C Library for LT_I2C: Routines to Communicate With ATmega328P's hardware I2C port. */ //#include <Arduino.h> #include <stdint.h> //#include <util/delay.h> #include "Linduino.h" #include "LT_I2C.h" #include "mbed.h" //! CPU master clock frequency #ifndef F_CPU #define F_CPU 16000000UL #endif Serial pc1(USBTX, USBRX, 9600); LT_I2C::LT_I2C() { i2c = new I2C(I2C_SDA, I2C_SCL); i2c->frequency(400000); //maximum from datasheet for ltc2991 } LT_I2C::LT_I2C(PinName sda_, PinName scl_) { sda = sda_; scl = scl_; i2c = new I2C(sda_ , scl_); i2c->frequency(400000); //maximum from datasheet for ltc2991 } // Read a byte of data at register specified by "command", store in "value" int8_t LT_I2C::i2c_read_byte_data(uint8_t address, uint8_t command, uint8_t *value) { int8_t ret = 0; char cmd1[1]; cmd1[0] = command; char v[1]; v[0] = 0; ret |= i2c->write((address<<1) | I2C_WRITE_BIT, cmd1, 1, true); ret |= i2c->read((address<<1) | I2C_READ_BIT, v, 1, false); *value = v[0]; if (ret == 0) { return 0; //success } return(1); } // Write a byte of data to register specified by "command" int8_t LT_I2C::i2c_write_byte_data(uint8_t address, uint8_t command, uint8_t value) { int8_t ret = 0; char cmd[2]; cmd[0] = command; cmd[1] = value; ret |= i2c->write((address<<1) | I2C_WRITE_BIT, cmd, 2, false); if (ret == 0) { return 0; //success } return(1); } int8_t LT_I2C::i2c_read_word_data(uint8_t address, uint8_t command, uint16_t *value) { int8_t ret = 0; union { char b[2]; uint16_t w; } data; char writedata[2]; writedata[0] = command; //msb writedata[1] = command+1; //lsb ret |= i2c->write((address << 1) | I2C_WRITE_BIT, &writedata[0], 1, true); ret |= i2c->read((address << 1) | I2C_READ_BIT, &data.b[1], 1, false); ret |= i2c->write((address << 1) | I2C_WRITE_BIT, &writedata[1], 1, true); ret |= i2c->read((address << 1) | I2C_READ_BIT, &data.b[0], 1, false); *value = data.w; if (ret == 0) { return 0; } return(1); } // Write a 16-bit word of data to register specified by "command" int8_t LT_I2C::i2c_write_word_data(uint8_t address, uint8_t command, uint16_t value) { int8_t ret = 0; union { uint8_t b[2]; uint16_t w; } data; data.w = value; char cmd[3]; cmd[0] = command; cmd[1] = data.b[1]; cmd[2] = data.b[0]; ret |= i2c->write((address<<1) | I2C_WRITE_BIT, cmd, 3, false); if (ret == 0) { return 0; } return(1); }