Linduino  1.3.0
Linear Technology Arduino-Compatible Demonstration Board
LTC2946.cpp
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1 /*!
2 LTC2946: 12-Bit Wide Range Power, Charge and Energy Monitor
3 
4 @verbatim
5 
6 The LTC®2946 is a rail-to-rail system monitor that measures
7 current, voltage, power, charge and energy. It features an
8 operating range of 2.7V to 100V and includes a shunt regulator
9 for supplies above 100V. The current measurement common mode
10 range of 0V to 100V is independent of the input supply.
11 A 12-bit ADC measures load current, input voltage and an
12 auxiliary external voltage. Load current and internally
13 calculated power are integrated over an external clock or
14 crystal or internal oscillator time base for charge and energy.
15 An accurate time base allows the LTC2946 to provide measurement
16 accuracy of better than ±0.6% for charge and ±1% for power and
17 energy. Minimum and maximum values are stored and an overrange
18 alert with programmable thresholds minimizes the need for software
19 polling. Data is reported via a standard I2C interface.
20 Shutdown mode reduces power consumption to 15uA.
21 
22 @endverbatim
23 
24 http://www.linear.com/product/LTC2946
25 
26 http://www.linear.com/product/ltc2946#demoboards
27 
28 
29 Copyright 2018(c) Analog Devices, Inc.
30 
31 All rights reserved.
32 
33 Redistribution and use in source and binary forms, with or without
34 modification, are permitted provided that the following conditions are met:
35  - Redistributions of source code must retain the above copyright
36  notice, this list of conditions and the following disclaimer.
37  - Redistributions in binary form must reproduce the above copyright
38  notice, this list of conditions and the following disclaimer in
39  the documentation and/or other materials provided with the
40  distribution.
41  - Neither the name of Analog Devices, Inc. nor the names of its
42  contributors may be used to endorse or promote products derived
43  from this software without specific prior written permission.
44  - The use of this software may or may not infringe the patent rights
45  of one or more patent holders. This license does not release you
46  from the requirement that you obtain separate licenses from these
47  patent holders to use this software.
48  - Use of the software either in source or binary form, must be run
49  on or directly connected to an Analog Devices Inc. component.
50 
51 THIS SOFTWARE IS PROVIDED BY ANALOG DEVICES "AS IS" AND ANY EXPRESS OR
52 IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, NON-INFRINGEMENT,
53 MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
54 IN NO EVENT SHALL ANALOG DEVICES BE LIABLE FOR ANY DIRECT, INDIRECT,
55 INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
56 LIMITED TO, INTELLECTUAL PROPERTY RIGHTS, PROCUREMENT OF SUBSTITUTE GOODS OR
57 SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
58 CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
59 OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
60 OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
61 */
62 
63 //! @ingroup Power_Monitors
64 //! @{
65 //! @defgroup LTC2946 LTC2946: 12-Bit Wide Range Power, Charge and Energy Monitor
66 //! @}
67 
68 /*! @file
69  @ingroup LTC2946
70  Library for LTC2946 12-Bit Wide Range Power, Charge and Energy Monitor
71 */
72 
73 #include <Arduino.h>
74 #include <stdint.h>
75 #include "Linduino.h"
76 #include "LT_I2C.h"
77 #include "LTC2946.h"
78 #include <Wire.h>
79 
80 // Write an 8-bit code to the LTC2946.
81 int8_t LTC2946_write(uint8_t i2c_address, uint8_t adc_command, uint8_t code)
82 // The function returns the state of the acknowledge bit after the I2C address write. 0=acknowledge, 1=no acknowledge.
83 {
84  int32_t ack;
85 
86  ack = i2c_write_byte_data(i2c_address, adc_command, code);
87 
88  return ack;
89 
90 }
91 
92 // Write a 16-bit code to the LTC2946.
93 int8_t LTC2946_write_16_bits(uint8_t i2c_address, uint8_t adc_command, uint16_t code)
94 // The function returns the state of the acknowledge bit after the I2C address write. 0=acknowledge, 1=no acknowledge.
95 {
96  int8_t ack;
97 
98  ack = i2c_write_word_data(i2c_address, adc_command, code);
99  return(ack);
100 }
101 
102 // Write a 24-bit code to the LTC2946.
103 int8_t LTC2946_write_24_bits(uint8_t i2c_address, uint8_t adc_command, uint32_t code)
104 // The function returns the state of the acknowledge bit after the I2C address write. 0=acknowledge, 1=no acknowledge.
105 {
106  int8_t ack;
107 
109  data.LT_int32 = code;
110 
111  ack = i2c_write_block_data(i2c_address, adc_command, (uint8_t) 3, data.LT_byte);
112 
113  return(ack);
114 }
115 
116 int8_t LTC2946_write_32_bits(uint8_t i2c_address, uint8_t adc_command, uint32_t code)
117 // The function returns the state of the acknowledge bit after the I2C address write. 0=acknowledge, 1=no acknowledge.
118 {
119  int8_t ack;
120 
122  data.LT_int32 = code;
123 
124  ack = i2c_write_block_data(i2c_address, adc_command, (uint8_t) 4, data.LT_byte);
125 
126  return(ack);
127 }
128 
129 // Reads an 8-bit adc_code from LTC2946
130 int8_t LTC2946_read(uint8_t i2c_address, uint8_t adc_command, uint8_t *adc_code)
131 // The function returns the state of the acknowledge bit after the I2C address write. 0=acknowledge, 1=no acknowledge.
132 {
133  int32_t ack;
134 
135  ack = i2c_read_byte_data(i2c_address, adc_command, adc_code);
136 
137  return ack;
138 }
139 
140 // Reads a 12-bit adc_code from LTC2946
141 int8_t LTC2946_read_12_bits(uint8_t i2c_address, uint8_t adc_command, uint16_t *adc_code)
142 // The function returns the state of the acknowledge bit after the I2C address write. 0=acknowledge, 1=no acknowledge.
143 {
144  // 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)
145  // Then, shift by 4 bits and return in *adc_code
146  int32_t ack;
147 
148  ack = i2c_read_word_data(i2c_address, adc_command, adc_code);
149 
150  *adc_code >>= 4;
151  return ack;
152 }
153 
154 // Reads a 16-bit adc_code from LTC2946
155 int8_t LTC2946_read_16_bits(uint8_t i2c_address, uint8_t adc_command, uint16_t *adc_code)
156 // The function returns the state of the acknowledge bit after the I2C address write. 0=acknowledge, 1=no acknowledge.
157 {
158  int32_t ack;
159 
160  ack = i2c_read_word_data(i2c_address, adc_command, adc_code);
161 
162  return ack;
163 }
164 
165 // Reads a 24-bit adc_code from LTC2946
166 int8_t LTC2946_read_24_bits(uint8_t i2c_address, uint8_t adc_command, uint32_t *adc_code)
167 // The function returns the state of the acknowledge bit after the I2C address write. 0=acknowledge, 1=no acknowledge.
168 {
169  int8_t ack;
170 
172 
173  ack = i2c_read_block_data(i2c_address, adc_command, (uint8_t)3, data.LT_byte);
174 
175  *adc_code = 0x0FFFFFF & data.LT_int32;
176  return(ack);
177 }
178 
179 // Reads a 32-bit adc_code from LTC2946
180 int8_t LTC2946_read_32_bits(uint8_t i2c_address, uint8_t adc_command, uint32_t *adc_code)
181 // The function returns the state of the acknowledge bit after the I2C address write. 0=acknowledge, 1=no acknowledge.
182 {
183  int8_t ack;
184 
186 
187  ack = i2c_read_block_data(i2c_address, adc_command, (uint8_t) 4, data.LT_byte);
188 
189  *adc_code = 0xFFFFFFFF & data.LT_int32;
190  return(ack);
191 }
192 
193 // Calculate the LTC2946 VIN voltage
195 // Returns the VIN Voltage in Volts
196 {
197  float voltage;
198  voltage = (float)adc_code*LTC2946_VIN_lsb; //! 1) Calculate voltage from code and lsb
199  return(voltage);
200 }
201 
202 // Calculate the LTC2946 ADIN voltage
204 // Returns the ADIN Voltage in Volts
205 {
206  float adc_voltage;
207  adc_voltage = (float)adc_code*LTC2946_ADIN_lsb; //! 1) Calculate voltage from code and ADIN lsb
208  return(adc_voltage);
209 }
210 
211 // Calculate the LTC2946 current with a sense resistor
213 // Returns the LTC2946 current in Amps
214 {
215  float voltage, current;
216  voltage = (float)adc_code*LTC2946_DELTA_SENSE_lsb; //! 1) Calculate voltage from ADC code and delta sense lsb
217  current = voltage/resistor; //! 2) Calculate current, I = V/R
218  return(current);
219 }
220 
221 // Calculate the LTC2946 power
223 // Returns The LTC2946 power in Watts
224 {
225  float power;
226  power = (float)adc_code*LTC2946_Power_lsb/resistor; //! 1) Calculate Power using Power lsb and resistor
227 
228  return(power);
229 }
230 
231 
232 // Calculate the LTC2946 energy
234 // Returns the LTC2946 energy in Joules
235 {
236  float energy_lsb, energy;
237  energy_lsb=(float)(LTC2946_Power_lsb/resistor)*65536*LTC2946_TIME_lsb; //! 1) Calculate Energy lsb from Power lsb and Time lsb
238  energy = adc_code*energy_lsb; //! 2) Calculate Energy using Energy lsb and adc code
239  return(energy);
240 }
241 
242 // Calculate the LTC2946 Coulombs
244 // Returns the LTC2946 Coulombs
245 {
246  float coulomb_lsb, coulombs;
247  coulomb_lsb=(float)(LTC2946_DELTA_SENSE_lsb/resistor)*16*LTC2946_TIME_lsb; //! 1) Calculate Coulomb lsb Current lsb and Time lsb
248  coulombs = adc_code*coulomb_lsb; //! 2) Calculate Coulombs using Coulomb lsb and adc code
249  return(coulombs);
250 }
251 
252 //Calculate the LTC2946 Time in Seconds
253 float LTC2946_code_to_time(float time_code, float LTC2946_TIME_lsb)
254 {
255  float seconds;
256  seconds = LTC2946_TIME_lsb * time_code;
257  return seconds;
258 }
259 
float LTC2946_code_to_energy(int32_t adc_code, float resistor, float LTC2946_Power_lsb, float LTC2946_TIME_lsb)
Calculate the LTC2946 energy.
Definition: LTC2946.cpp:233
int8_t LTC2946_write_16_bits(uint8_t i2c_address, uint8_t adc_command, uint16_t code)
Write a 16-bit code to the LTC2946.
Definition: LTC2946.cpp:93
float LTC2946_code_to_power(int32_t adc_code, float resistor, float LTC2946_Power_lsb)
Calculate the LTC2946 power.
Definition: LTC2946.cpp:222
uint8_t i2c_address
static uint8_t adc_command
Definition: DC2071AA.ino:111
int8_t i2c_read_block_data(uint8_t address, uint8_t command, uint8_t length, uint8_t *values)
Read a block of data, starting at register specified by "command" and ending at (command + length - 1...
Definition: LT_I2C.cpp:244
uint8_t LT_byte[4]
4 bytes (unsigned 8-bit integers) to be converted to a 32-bit signed or unsigned integer ...
Definition: Linduino.h:112
int8_t i2c_read_byte_data(uint8_t address, uint8_t command, uint8_t *value)
Read a byte of data at register specified by "command", store in "value".
Definition: LT_I2C.cpp:124
const float LTC2946_ADIN_lsb
Typical ADIN lsb weight in volts.
Definition: DC2156.ino:127
const float resistor
resistor value on demo board
Definition: DC1496BB.ino:116
int8_t LTC2946_read(uint8_t i2c_address, uint8_t adc_command, uint8_t *adc_code)
Reads an 8-bit adc_code from LTC2946.
Definition: LTC2946.cpp:130
int8_t LTC2946_write_24_bits(uint8_t i2c_address, uint8_t adc_command, uint32_t code)
Write a 24-bit code to the LTC2946.
Definition: LTC2946.cpp:103
Header File for Linduino Libraries and Demo Code.
int8_t LTC2946_read_16_bits(uint8_t i2c_address, uint8_t adc_command, uint16_t *adc_code)
Reads a 16-bit adc_code from LTC2946.
Definition: LTC2946.cpp:155
int8_t LTC2946_read_12_bits(uint8_t i2c_address, uint8_t adc_command, uint16_t *adc_code)
Reads a 12-bit adc_code from LTC2946.
Definition: LTC2946.cpp:141
const float LTC2946_VIN_lsb
Typical VIN lsb weight in volts.
Definition: DC2156.ino:129
static float adc_voltage
Definition: DC2071AA.ino:115
union LT_union_int32_4bytes data
Definition: DC2094A.ino:138
float LTC2946_code_to_time(float time_code, float LTC2946_TIME_lsb)
Calculate the LTC2946 internal time base.
Definition: LTC2946.cpp:253
int8_t LTC2946_read_24_bits(uint8_t i2c_address, uint8_t adc_command, uint32_t *adc_code)
Reads a 24-bit adc_code from LTC2946.
Definition: LTC2946.cpp:166
float LTC2946_ADIN_code_to_voltage(uint16_t adc_code, float LTC2946_ADIN_lsb)
Calculate the LTC2946 ADIN voltage.
Definition: LTC2946.cpp:203
int8_t LTC2946_write(uint8_t i2c_address, uint8_t adc_command, uint8_t code)
Write an 8-bit code to the LTC2946.
Definition: LTC2946.cpp:81
int8_t i2c_write_word_data(uint8_t address, uint8_t command, uint16_t value)
Write a 16-bit word of data to register specified by "command".
Definition: LT_I2C.cpp:216
int8_t i2c_write_byte_data(uint8_t address, uint8_t command, uint8_t value)
Write a byte of data to register specified by "command".
Definition: LT_I2C.cpp:155
static float LTC2946_TIME_lsb
Static variable which is based off of the default clk frequency of 250KHz.
Definition: DC2156.ino:134
int32_t LT_int32
32-bit signed integer to be converted to four bytes
Definition: Linduino.h:110
int8_t LTC2946_write_32_bits(uint8_t i2c_address, uint8_t adc_command, uint32_t code)
Write a 32-bit code to the LTC2946.
Definition: LTC2946.cpp:116
int8_t i2c_read_word_data(uint8_t address, uint8_t command, uint16_t *value)
Read a 16-bit word of data from register specified by "command".
Definition: LT_I2C.cpp:172
LT_I2C: Routines to communicate with ATmega328P&#39;s hardware I2C port.
int8_t i2c_write_block_data(uint8_t address, uint8_t command, uint8_t length, uint8_t *values)
Write a block of data, starting at register specified by "command" and ending at (command + length - ...
Definition: LT_I2C.cpp:321
This union splits one int32_t (32-bit signed integer) or uint32_t (32-bit unsigned integer) four uint...
Definition: Linduino.h:108
LTC2946: 12-Bit Wide Range Power, Charge and Energy Monitor.
float LTC2946_VIN_code_to_voltage(uint16_t adc_code, float LTC2946_VIN_lsb)
Calculate the LTC2946 VIN voltage.
Definition: LTC2946.cpp:194
static float voltage
Definition: DC2289AA.ino:71
static uint16_t current
the current measurement from the LTC3335&#39;s counter test mode.
Definition: DC2343A.ino:114
const float LTC2946_Power_lsb
Typical POWER lsb weight in V^2 VIN_lsb * DELTA_SENSE_lsb.
Definition: DC2156.ino:130
float LTC2946_code_to_current(uint16_t adc_code, float resistor, float LTC2946_DELTA_SENSE_lsb)
Calculate the LTC2946 current with a sense resistor.
Definition: LTC2946.cpp:212
int8_t LTC2946_read_32_bits(uint8_t i2c_address, uint8_t adc_command, uint32_t *adc_code)
Reads a 32-bit adc_code from LTC2946.
Definition: LTC2946.cpp:180
static uint32_t adc_code
Definition: DC2071AA.ino:113
float LTC2946_code_to_coulombs(int32_t adc_code, float resistor, float LTC2946_DELTA_SENSE_lsb, float LTC2946_TIME_lsb)
Calculate the LTC2946 coulombs.
Definition: LTC2946.cpp:243
const float LTC2946_DELTA_SENSE_lsb
Typical Delta lsb weight in volts.
Definition: DC2156.ino:128