Diff: LTC2945.cpp

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0:6be57f391716

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+/*!
+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);
+}
+
+}