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LTC2990.cpp
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1 /*!
2 LTC2990: 14-bit Quad I2C Voltage, Current, and Temperature Monitor
3
4 @verbatim
5
6 The LTC2990 is used to monitor system temperatures, voltages and currents.
7 Through the I2C serial interface, the four monitors can individually measure
8 supply voltages and can be paired for differential measurements of current sense
9 resistors or temperature sensing transistors. Additional measurements include
10 internal temperature and internal VCC. The internal 10ppm reference minimizes
11 the number of supporting components and area required. Selectable address and
12 configurable functionality give the LTC2990 flexibility to be incorporated in
13 various systems needing temperature, voltage or current data. The LTC2990 fits
14 well in systems needing sub-millivolt voltage resolution, 1% current measurement
15 and 1 degree Celsius temperature accuracy or any combination of the three.
16
17 @endverbatim
18
19 http://www.linear.com/product/LTC2990
20
21 http://www.linear.com/product/LTC2990#demoboards
22
23
24 Copyright 2018(c) Analog Devices, Inc.
25
26 All rights reserved.
27
28 Redistribution and use in source and binary forms, with or without
29 modification, are permitted provided that the following conditions are met:
30 - Redistributions of source code must retain the above copyright
31 notice, this list of conditions and the following disclaimer.
32 - Redistributions in binary form must reproduce the above copyright
33 notice, this list of conditions and the following disclaimer in
34 the documentation and/or other materials provided with the
35 distribution.
36 - Neither the name of Analog Devices, Inc. nor the names of its
37 contributors may be used to endorse or promote products derived
38 from this software without specific prior written permission.
39 - The use of this software may or may not infringe the patent rights
40 of one or more patent holders. This license does not release you
41 from the requirement that you obtain separate licenses from these
42 patent holders to use this software.
43 - Use of the software either in source or binary form, must be run
44 on or directly connected to an Analog Devices Inc. component.
45
46 THIS SOFTWARE IS PROVIDED BY ANALOG DEVICES "AS IS" AND ANY EXPRESS OR
47 IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, NON-INFRINGEMENT,
48 MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
49 IN NO EVENT SHALL ANALOG DEVICES BE LIABLE FOR ANY DIRECT, INDIRECT,
50 INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
51 LIMITED TO, INTELLECTUAL PROPERTY RIGHTS, PROCUREMENT OF SUBSTITUTE GOODS OR
52 SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
53 CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
54 OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
55 OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
56 */
57
58 //! @ingroup Power_Monitors
59 //! @{
60 //! @defgroup LTC2990 LTC2990: 14-bit Quad I2C Voltage, Current, and Temperature Monitor
61 //! @}
62
63 /*! @file
64 @ingroup LTC2990
65 Library for LTC2990: 14-bit Quad I2C Voltage, Current, and Temperature Monitor
66 */
67
68 #include <Arduino.h>
69 #include <stdint.h>
70 #include "Linduino.h"
71 #include "LT_I2C.h"
72 #include "LTC2990.h"
73 #include <Wire.h>
74
75 // Reads a 14-bit adc_code from LTC2990.
76 int8_t LTC2990_adc_read(uint8_t i2c_address, uint8_t msb_register_address, int16_t *adc_code, int8_t *data_valid)
77 {
78 int8_t ack = 0;
79 uint16_t code;
80 ack = i2c_read_word_data(i2c_address, msb_register_address, &code);
81
82 *data_valid = (code >> 15) & 0x01; // Place Data Valid Bit in *data_valid
83
84 *adc_code = code & 0x7FFF; // Removes data valid bit to return proper adc_code value
85
86 return(ack);
87 }
88
89 // Reads a 14-bit adc_code from the LTC2990 but enforces a maximum timeout.
90 // Similar to LTC2990_adc_read except it repeats until the data_valid bit is set, it fails to receive an I2C acknowledge, or the timeout (in milliseconds)
91 // expires. It keeps trying to read from the LTC2990 every millisecond until the data_valid bit is set (indicating new data since the previous
92 // time this register was read) or until it fails to receive an I2C acknowledge (indicating an error on the I2C bus).
93 int8_t LTC2990_adc_read_timeout(uint8_t i2c_address, uint8_t msb_register_address, int16_t *adc_code, int8_t *data_valid, uint16_t timeout, uint8_t status_bit)
94 {
95 int8_t ack = 0;
96 uint8_t reg_data;
97 uint16_t timer_count; // Timer count for data_valid
98 *data_valid = 0;
99
100 for (timer_count = 0; timer_count < timeout; timer_count++)
101 {
102
103 ack |= LTC2990_register_read(i2c_address, LTC2990_STATUS_REG, &reg_data); //! 1)Read status register until correct data valid bit is set
104
105 if ((ack) || (((reg_data>>status_bit)&0x1)==1))
106 {
107 break;
108 }
109 delay(1);
110 }
111 ack |= LTC2990_adc_read(i2c_address, msb_register_address, &(*adc_code), &(*data_valid)); //! 2) It's either valid or it's timed out, we read anyways
112 if (*data_valid !=1)
113 {
114 return (1);
115 }
116 return(ack);
117 }
118
119 // Reads new data (even after a mode change) by flushing old data and waiting for the data_valid bit to be set.
120 // This function simplifies adc reads when modes are changing. For example, if V1-V2 changes from temperature mode
121 // to differential voltage mode, the data in the register may still correspond to the temperature reading immediately
122 // after the mode change. Flushing one reading and waiting for a new reading guarantees fresh data is received.
123 // If the timeout is reached without valid data (*data_valid=1) the function exits.
124 int8_t LTC2990_adc_read_new_data(uint8_t i2c_address, uint8_t msb_register_address, int16_t *adc_code, int8_t *data_valid, uint16_t timeout)
125 {
126 int8_t ack = 0;
127 uint8_t status_bit;
128 status_bit = msb_register_address/2-1;
129 ack |= LTC2990_adc_read_timeout(i2c_address, msb_register_address, adc_code, data_valid, timeout, status_bit); //! 1) Throw away old data
130
131 ack |= LTC2990_adc_read_timeout(i2c_address, msb_register_address, adc_code, data_valid, timeout,status_bit); //! 2) Read new data
132
133 return(ack);
134 }
135
136 // Reads an 8-bit register from the LTC2990 using the standard repeated start format.
137 int8_t LTC2990_register_read(uint8_t i2c_address, uint8_t register_address, uint8_t *register_data)
138 {
139 int8_t ack = 0;
140
141 ack = i2c_read_byte_data(i2c_address, register_address, register_data);
142 return(ack);
143 }
144
145 // Write one byte to an LTC2990 register.
146 // Writes to an 8-bit register inside the LTC2990 using the standard I2C repeated start format.
147 int8_t LTC2990_register_write(uint8_t i2c_address, uint8_t register_address, uint8_t register_data)
148 {
149 int8_t ack = 0;
150
151 ack = i2c_write_byte_data(i2c_address, register_address, register_data);
152 return(ack);
153 }
154
155 // Used to set and clear bits in a control register. bits_to_set will be bitwise OR'd with the register.
156 // bits_to_clear will be inverted and bitwise AND'd with the register so that every location with a 1 will result in a 0 in the register.
157 int8_t LTC2990_register_set_clear_bits(uint8_t i2c_address, uint8_t register_address, uint8_t bits_to_set, uint8_t bits_to_clear)
158 {
159 uint8_t register_data;
160 int8_t ack = 0;
161
162 ack |= LTC2990_register_read(i2c_address, register_address, &register_data); //! 1) Read register
163 register_data = register_data & (~bits_to_clear); //! 2) Clear bits that were set to be cleared
164 register_data = register_data | bits_to_set;
165 ack |= LTC2990_register_write(i2c_address, register_address, register_data); //! 3) Write to register with the cleared bits
166 return(ack);
167 }
168
169 // Calculates the LTC2990 single-ended input voltages
170 float LTC2990_code_to_single_ended_voltage(int16_t adc_code, float LTC2990_single_ended_lsb)
171 {
172 float voltage;
173 int16_t sign = 1;
174 if (adc_code >> 14)
175 {
176 adc_code = (adc_code ^ 0x7FFF) + 1; //! 1) Converts two's complement to binary
177 sign = -1;
178 }
179 adc_code = (adc_code & 0x3FFF);
180 voltage = ((float) adc_code) * LTC2990_single_ended_lsb * sign; //! 2) Convert code to voltage from lsb
181 return (voltage);
182 }
183
184 // Calculates the LTC2990 Vcc voltage
185 float LTC2990_code_to_vcc_voltage(int16_t adc_code, float LTC2990_single_ended_lsb)
186 {
187 float voltage;
188 int16_t sign = 1;
189 if (adc_code >> 14)
190 {
191 adc_code = (adc_code ^ 0x7FFF) + 1; //! 1) Converts two's complement to binary
192 sign = -1;
193 }
194
195 voltage = (((float) adc_code) * LTC2990_single_ended_lsb * sign) + 2.5; //! 2) Convert code to Vcc Voltage from single-ended lsb
196 return (voltage);
197 }
198
199 // Calculates the LTC2990 differential input voltage.
200 float LTC2990_code_to_differential_voltage(int16_t adc_code, float LTC2990_differential_lsb)
201 {
202 float voltage;
203 int16_t sign = 1;
204 if (adc_code >> 14)
205 {
206 adc_code = (adc_code ^ 0x7FFF) + 1; //! 1)Converts two's complement to binary
207 sign = -1;
208 }
209 voltage = ((float) adc_code) * LTC2990_differential_lsb * sign; //! 2) Convert code to voltage form differential lsb
210 return (voltage);
211 }
212
213 // Calculates the LTC2990 temperature
214 float LTC2990_temperature(int16_t adc_code, float LTC2990_temperature_lsb, boolean unit)
215 {
216 float temperature;
217 adc_code = (adc_code & 0x1FFF); //! 1) Removes first 3 bits
218 if (!unit) //! 2)Checks to see if it's Kelvin
219 {
220 if (adc_code >>12)
221 {
222 adc_code = (adc_code | 0xE000); //! Sign extend if it's not Kelvin (Celsius)
223 }
224 }
225 temperature = ((float) adc_code) * LTC2990_temperature_lsb; //! 3) Converts code to temperature from temperature lsb
226
227 return (temperature);
228 }
229
230 // Calculates the LTC2990 diode voltage
231 float LTC2990_code_to_diode_voltage(int16_t adc_code, float LTC2990_diode_voltage_lsb)
232 {
233 float voltage;
234 adc_code = (adc_code & 0x1FFF); //! 1) Removes first 3 bits
235 voltage = ((float) adc_code) * LTC2990_diode_voltage_lsb; //! 2) Convert code to voltage from diode voltage lsb
236 return (voltage);
237 }
i2c_address
uint8_t i2c_address
sign
bool sign
Definition: Precision_Voltage_Source.ino:77
LTC2990_adc_read
int8_t LTC2990_adc_read(uint8_t i2c_address, uint8_t msb_register_address, int16_t *adc_code, int8_t *data_valid)
Reads a 14-bit adc_code from LTC2990.
Definition: LTC2990.cpp:76
LTC2990_STATUS_REG
#define LTC2990_STATUS_REG
Indicates BUSY state and conversion status.
Definition: LTC2990.h:170
i2c_read_byte_data
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
LTC2990_code_to_single_ended_voltage
float LTC2990_code_to_single_ended_voltage(int16_t adc_code, float LTC2990_single_ended_lsb)
Calculates the LTC2990 single-ended input voltages.
Definition: LTC2990.cpp:170
Linduino.h
Header File for Linduino Libraries and Demo Code.
LTC2990_adc_read_new_data
int8_t LTC2990_adc_read_new_data(uint8_t i2c_address, uint8_t msb_register_address, int16_t *adc_code, int8_t *data_valid, uint16_t timeout)
Reads new data (even after a mode change) by flushing old data and waiting for the data_valid bit to ...
Definition: LTC2990.cpp:124
LTC2990_code_to_vcc_voltage
float LTC2990_code_to_vcc_voltage(int16_t adc_code, float LTC2990_single_ended_lsb)
Calculates the LTC2990 Vcc voltage.
Definition: LTC2990.cpp:185
LTC2990.h
LTC2990: 14-bit ADC Quad I2C voltage, current, and temperature monitor.
LTC2990_register_set_clear_bits
int8_t LTC2990_register_set_clear_bits(uint8_t i2c_address, uint8_t register_address, uint8_t bits_to_set, uint8_t bits_to_clear)
Used to set and clear bits in a control register.
Definition: LTC2990.cpp:157
LTC2990_register_write
int8_t LTC2990_register_write(uint8_t i2c_address, uint8_t register_address, uint8_t register_data)
Write one byte to an LTC2990 register.
Definition: LTC2990.cpp:147
i2c_write_byte_data
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
LTC2990_register_read
int8_t LTC2990_register_read(uint8_t i2c_address, uint8_t register_address, uint8_t *register_data)
Reads an 8-bit register from the LTC2990 using the standard repeated start format.
Definition: LTC2990.cpp:137
LTC2990_adc_read_timeout
int8_t LTC2990_adc_read_timeout(uint8_t i2c_address, uint8_t msb_register_address, int16_t *adc_code, int8_t *data_valid, uint16_t timeout, uint8_t status_bit)
Reads a 14-bit adc_code from the LTC2990 but enforces a maximum timeout.
Definition: LTC2990.cpp:93
timeout
long timeout
Definition: EVAL-AD7124-8.ino:144
i2c_read_word_data
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.h
LT_I2C: Routines to communicate with ATmega328P&#39;s hardware I2C port.
LTC2990_temperature
float LTC2990_temperature(int16_t adc_code, float LTC2990_temperature_lsb, boolean unit)
Calculates the LTC2990 temperature.
Definition: LTC2990.cpp:214
LTC2990_code_to_differential_voltage
float LTC2990_code_to_differential_voltage(int16_t adc_code, float LTC2990_differential_lsb)
Calculates the LTC2990 differential input voltage.
Definition: LTC2990.cpp:200
voltage
static float voltage
Definition: DC2289AA.ino:71
LTC2990_code_to_diode_voltage
float LTC2990_code_to_diode_voltage(int16_t adc_code, float LTC2990_diode_voltage_lsb)
Calculates the LTC2990 diode voltage.
Definition: LTC2990.cpp:231
adc_code
static uint32_t adc_code
Definition: DC2071AA.ino:113