![](/media/cache/profiles/eb1feb5ab28dec83652dd1e5c673f256.jpg.50x50_q85.jpg)
LTC2945 ported
Diff: LTC2945.cpp
- Revision:
- 0:6be57f391716
- Child:
- 4:d32eaca53504
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/LTC2945.cpp Wed Aug 23 10:49:21 2017 +0000 @@ -0,0 +1,234 @@ +/*! +LTC2945: 12-Bit Wide Range Power Monitor + +@verbatim + +The LTC2945 is a rail-to-rail system monitor that measures current, voltage, and +power. It features an operating range of 2.7V to 80V and includes a shunt +regulator for supplies above 80V to allow flexibility in the selection of input +supply. The current measurement range of 0V to 80V is independent of the input +supply. An onboard 0.75% accurate 12-bit ADC measures load current, input +voltage and an auxiliary external voltage. A 24-bit power value is generated by +digitally multiplying the measured 12-bit load current and input voltage data. +Minimum and maximum values are stored and an overrange alert with programmable +thresholds minimizes the need for software polling. Data is reported via a +standard I2C interface. Shutdown mode reduces power consumption to 20uA. + +@endverbatim + +http://www.linear.com/product/LTC2945 + +http://www.linear.com/product/ltc2945#demoboards + +REVISION HISTORY +$Revision: 6237 $ +$Date: 2016-12-20 15:09:16 -0800 (Tue, 20 Dec 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. +*/ + +//! @ingroup Power_Monitors +//! @{ +//! @defgroup LTC2945 LTC2945: 12-Bit Wide Range Power Monitor +//! @} + +/*! @file + @ingroup LTC2945 + Library for LTC2945 12-Bit Wide Range Power Monitor +*/ + +#include "LT_I2C.h" +#include "LTC2945.h" + +/* compatibility definitions */ + +#define i2c_start lt_i2c_start +#define i2c_stop lt_i2c_stop +#define i2c_write lt_i2c_write +#define i2c_write_byte_data lt_i2c_write_byte_data +#define i2c_write_word_data lt_i2c_write_word_data +#define i2c_write_block_data lt_i2c_write_block_data +#define i2c_read lt_i2c_read +#define i2c_read_byte_data lt_i2c_read_byte_data +#define i2c_read_word_data lt_i2c_read_word_data +#define i2c_read_block_data lt_i2c_read_block_data + +/* definitions in Linduino.h, that doesn't exist here */ +//! @todo Make a note about whether Arduino/Linduino is Big Endian or Little Endian. Raspberry Pi appears to be the opposite. +//! This union splits one int32_t (32-bit signed integer) or uint32_t (32-bit unsigned integer) +//! into four uint8_t's (8-bit unsigned integers) and vice versa. +union LT_union_int32_4bytes +{ + int32_t LT_int32; //!< 32-bit signed integer to be converted to four bytes + uint32_t LT_uint32; //!< 32-bit unsigned integer to be converted to four bytes + uint8_t LT_byte[4]; //!< 4 bytes (unsigned 8-bit integers) to be converted to a 32-bit signed or unsigned integer +}; + +extern "C" { + +// Write an 8-bit code to the LTC2945. +int8_t LTC2945_write(uint8_t i2c_address, uint8_t adc_command, uint8_t code) +// The function returns the state of the acknowledge bit after the I2C address write. 0=acknowledge, 1=no acknowledge. +{ + int32_t ack; + + ack = i2c_write_byte_data(i2c_address, adc_command, code); + + return ack; + +} + +// Write a 16-bit code to the LTC2945. +int8_t LTC2945_write_16_bits(uint8_t i2c_address, uint8_t adc_command, uint16_t code) +// The function returns the state of the acknowledge bit after the I2C address write. 0=acknowledge, 1=no acknowledge. +{ + int8_t ack; + + ack = i2c_write_word_data(i2c_address, adc_command, code); + return(ack); +} + +// Write a 24-bit code to the LTC2945. +int8_t LTC2945_write_24_bits(uint8_t i2c_address, uint8_t adc_command, int32_t code) +// The function returns the state of the acknowledge bit after the I2C address write. 0=acknowledge, 1=no acknowledge. +{ + int8_t ack; + + LT_union_int32_4bytes data; + data.LT_int32 = code; + + ack = i2c_write_block_data(i2c_address, adc_command, (uint8_t) 3, data.LT_byte); + + return(ack); +} + +// Reads an 8-bit adc_code from LTC2945 +int8_t LTC2945_read(uint8_t i2c_address, uint8_t adc_command, uint8_t *adc_code) +// The function returns the state of the acknowledge bit after the I2C address write. 0=acknowledge, 1=no acknowledge. +{ + int32_t ack; + + ack = i2c_read_byte_data(i2c_address, adc_command, adc_code); + + return ack; +} + +// Reads a 12-bit adc_code from LTC2945 +int8_t LTC2945_read_12_bits(uint8_t i2c_address, uint8_t adc_command, uint16_t *adc_code) +// The function returns the state of the acknowledge bit after the I2C address write. 0=acknowledge, 1=no acknowledge. +{ + // Use union type defined in Linduino.h to combine two uint8_t's (8-bit unsigned integers) into one uint16_t (unsigned 16-bit integer) + // Then, shift by 4 bits and return in *adc_code + int32_t ack; + + ack = i2c_read_word_data(i2c_address, adc_command, adc_code); + + *adc_code >>= 4; + return ack; +} + +// Reads a 16-bit adc_code from LTC2945 +int8_t LTC2945_read_16_bits(uint8_t i2c_address, uint8_t adc_command, uint16_t *adc_code) +// The function returns the state of the acknowledge bit after the I2C address write. 0=acknowledge, 1=no acknowledge. +{ + int32_t ack; + + ack = i2c_read_word_data(i2c_address, adc_command, adc_code); + + return ack; +} + +// Reads a 24-bit adc_code from LTC2945 +int8_t LTC2945_read_24_bits(uint8_t i2c_address, uint8_t adc_command, int32_t *adc_code) +// The function returns the state of the acknowledge bit after the I2C address write. 0=acknowledge, 1=no acknowledge. +{ + int8_t ack; + + LT_union_int32_4bytes data; + + ack = i2c_read_block_data(i2c_address, adc_command, (uint8_t)3, data.LT_byte); + + *adc_code = 0x0FFFFFF & data.LT_int32; + return(ack); +} + +// Calculate the LTC2945 VIN voltage +float LTC2945_VIN_code_to_voltage(uint16_t adc_code, float LTC2945_VIN_lsb) +// Returns the VIN Voltage in Volts +{ + float voltage; + voltage = (float)adc_code*LTC2945_VIN_lsb; //! 1) Calculate voltage from code and lsb + return(voltage); +} + +// Calculate the LTC2945 ADIN voltage +float LTC2945_ADIN_code_to_voltage(uint16_t adc_code, float LTC2945_ADIN_lsb) +// Returns the ADIN Voltage in Volts +{ + float adc_voltage; + adc_voltage = (float)adc_code*LTC2945_ADIN_lsb; //! 1) Calculate voltage from code and ADIN lsb + return(adc_voltage); +} + +// Calculate the LTC2945 current with a sense resistor +float LTC2945_code_to_current(uint16_t adc_code, float resistor, float LTC2945_DELTA_SENSE_lsb) +// Returns the LTC2945 current +{ + float voltage, current; + voltage = (float)adc_code*LTC2945_DELTA_SENSE_lsb; //! 1) Calculate voltage from ADC code and delta sense lsb + current = voltage/resistor; //! 2) Calculate current, I = V/R + return(current); +} + +// Calculate the LTC2945 power +float LTC2945_code_to_power(int32_t adc_code, float resistor, float LTC2945_Power_lsb) +// Returns The LTC2945 power +{ + float voltage, power; + voltage = (float)adc_code*LTC2945_Power_lsb; //! 1) Calculate V^2 from ADC code and power lsb + power = voltage/resistor; //! 2) Calculate Power, P = V^2/R + return(power); +} + +// Calculate the LTC2945 power with the ADIN +float LTC2945_code_to_ADIN_power(int32_t adc_code, float resistor, float LTC2945_ADIN_DELTA_SENSE_lsb) +// Returns the LTC2945 power with the ADIN +{ + float voltage, power; + voltage=(float)adc_code*LTC2945_ADIN_DELTA_SENSE_lsb; //! 1) Calculate V^2 from ADC code and ADIN delta sense lsb + power = voltage/resistor; //! 2) Calculate Power, P = V^2/R + return(power); +} + +}