drivers/sensors/ina219/ina219.c

   1 /**************************************************************************/
   2 /*!
   3     @file     ina219.c
   4     @author   K. Townsend (microBuilder.eu)
   5
   6     @brief    Driver for the TI INA219 current/power monitor
   7
   8     @section DESCRIPTION
   9
  10     The INA219 is an I2C-based current/power monitor that monitors the
  11         voltage drop across a shunt resistor, as well as the supply voltage.
  12
  13     @section EXAMPLE
  14     @code
  15     ina219Init();
  16
  17     int16_t current = 0;
  18     int16_t power = 0;
  19     int16_t current_mA = 0;
  20     int16_t power_mW = 0;
  21     int16_t busvoltage = 0;
  22     int16_t shuntvoltage = 0;
  23     int16_t loadVoltage = 0;
  24
  25     while(1)
  26     {
  27       shuntvoltage  = ina219GetShuntVoltage();
  28       busvoltage    = ina219GetBusVoltage();
  29       power         = ina219GetPower();
  30       current       = ina219GetCurrent();
  31       power_mW      = ina219GetPower_mW();
  32       current_mA    = ina219GetCurrent_mA();
  33       loadVoltage   = busvoltage + (shuntvoltage / 100);
  34       printf("%-15s %6d = %d.%dmV (%duV) \r\n", "Shunt Voltage:", shuntvoltage, shuntvoltage / 100, shuntvoltage % 100, shuntvoltage * 10);
  35       printf("%-15s %6d = %d.%dV \r\n",         "Bus Voltage:",   busvoltage, busvoltage / 1000, busvoltage % 1000);
  36       printf("%-15s %6d = %d.%dV \r\n",         "Load Voltage:",  loadVoltage, loadVoltage / 1000, loadVoltage % 1000);
  37       printf("%-15s %6d = %dmW \r\n",           "Power:",         power, power_mW);
  38       printf("%-15s %6d = %dmA \r\n",           "Current:",       current, current_mA);
  39       printf("\r\n");
  40       systickDelay(5000);
  41     }
  42     @endcode
  43
  44     @section LICENSE
  45
  46     Software License Agreement (BSD License)
  47
  48     Copyright (c) 2012 Kevin Townsend
  49     All rights reserved.
  50
  51     Redistribution and use in source and binary forms, with or without
  52     modification, are permitted provided that the following conditions are met:
  53     1. Redistributions of source code must retain the above copyright
  54     notice, this list of conditions and the following disclaimer.
  55     2. Redistributions in binary form must reproduce the above copyright
  56     notice, this list of conditions and the following disclaimer in the
  57     documentation and/or other materials provided with the distribution.
  58     3. Neither the name of the copyright holders nor the
  59     names of its contributors may be used to endorse or promote products
  60     derived from this software without specific prior written permission.
  61
  62     THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS ''AS IS'' AND ANY
  63     EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  64     WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  65     DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE FOR ANY
  66     DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
  67     (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  68     LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
  69     ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  70     (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  71     SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  72 */
  73 /**************************************************************************/
  74 #include "ina219.h"
  75 #include "core/systick/systick.h"
  76
  77 extern volatile uint8_t   I2CMasterBuffer[I2C_BUFSIZE];
  78 extern volatile uint8_t   I2CSlaveBuffer[I2C_BUFSIZE];
  79
  80 // The following multipliers are used to convert raw current and power
  81 // values to mA and mW, taking into account the current config settings
  82 uint32_t ina219_currentDivider_mA = 0;
  83 uint32_t ina219_powerDivider_mW   = 0;
  84
  85 /**************************************************************************/
  86 /*!
  87     @brief  Sends a single command byte over I2C
  88 */
  89 /**************************************************************************/
  90 static void ina219WriteRegister (uint8_t reg, uint16_t value)
  91 {
  92   // Clear write buffers
  93   uint32_t i;
  94   for ( i = 0; i < I2C_BUFSIZE; i++ )
  95   {
  96     I2CMasterBuffer[i] = 0x00;
  97   }
  98
  99   I2CWriteLength = 4;
 100   I2CReadLength = 0;
 101   I2CMasterBuffer[0] = INA219_ADDRESS;        // I2C device address
 102   I2CMasterBuffer[1] = reg;                   // Register
 103   I2CMasterBuffer[2] = value >> 8;            // Upper 8-bits
 104   I2CMasterBuffer[3] = value & 0xFF;          // Lower 8-bits
 105   i2cEngine();
 106 }
 107
 108 /**************************************************************************/
 109 /*!
 110     @brief  Reads a 16 bit values over I2C
 111 */
 112 /**************************************************************************/
 113 static void ina219Read16(uint8_t reg, uint16_t *value)
 114 {
 115   // Clear write buffers
 116   uint32_t i;
 117   for ( i = 0; i < I2C_BUFSIZE; i++ )
 118   {
 119     I2CMasterBuffer[i] = 0x00;
 120   }
 121
 122   I2CWriteLength = 2;
 123   I2CReadLength = 2;
 124   I2CMasterBuffer[0] = INA219_ADDRESS;            // I2C device address
 125   I2CMasterBuffer[1] = reg;                       // Command register
 126   // Append address w/read bit
 127   I2CMasterBuffer[2] = INA219_ADDRESS | INA219_READ;
 128   i2cEngine();
 129
 130   // Shift values to create properly formed integer
 131   *value = ((I2CSlaveBuffer[0] << 8) | I2CSlaveBuffer[1]);
 132 }
 133
 134 /**************************************************************************/
 135 /*!
 136     @brief  Configures to INA219 to be able to measure up to 32V and 2A
 137             of current.  Each unit of current corresponds to 100uA, and
 138             each unit of power corresponds to 2mW. Counter overflow
 139             occurs at 3.2A.
 140
 141     @note   These calculations assume a 0.1 ohm resistor is present
 142 */
 143 /**************************************************************************/
 144 void ina219SetCalibration_32V_2A(void)
 145 {
 146   // By default we use a pretty huge range for the input voltage,
 147   // which probably isn't the most appropriate choice for system
 148   // that don't use a lot of power.  But all of the calculations
 149   // are shown below if you want to change the settings.  You will
 150   // also need to change any relevant register settings, such as
 151   // setting the VBUS_MAX to 16V instead of 32V, etc.
 152
 153   // VBUS_MAX = 32V             (Assumes 32V, can also be set to 16V)
 154   // VSHUNT_MAX = 0.32          (Assumes Gain 8, 320mV, can also be 0.16, 0.08, 0.04)
 155   // RSHUNT = 0.1               (Resistor value in ohms)
 156
 157   // 1. Determine max possible current
 158   // MaxPossible_I = VSHUNT_MAX / RSHUNT
 159   // MaxPossible_I = 3.2A
 160
 161   // 2. Determine max expected current
 162   // MaxExpected_I = 2.0A
 163
 164   // 3. Calculate possible range of LSBs (Min = 15-bit, Max = 12-bit)
 165   // MinimumLSB = MaxExpected_I/32767
 166   // MinimumLSB = 0.000061              (61µA per bit)
 167   // MaximumLSB = MaxExpected_I/4096
 168   // MaximumLSB = 0,000488              (488µA per bit)
 169
 170   // 4. Choose an LSB between the min and max values
 171   //    (Preferrably a roundish number close to MinLSB)
 172   // CurrentLSB = 0.0001 (100µA per bit)
 173
 174   // 5. Compute the calibration register
 175   // Cal = trunc (0.04096 / (Current_LSB * RSHUNT))
 176   // Cal = 4096 (0x1000)
 177
 178   // 6. Calculate the power LSB
 179   // PowerLSB = 20 * CurrentLSB
 180   // PowerLSB = 0.002 (2mW per bit)
 181
 182   // 7. Compute the maximum current and shunt voltage values before overflow
 183   //
 184   // Max_Current = Current_LSB * 32767
 185   // Max_Current = 3.2767A before overflow
 186   //
 187   // If Max_Current > Max_Possible_I then
 188   //    Max_Current_Before_Overflow = MaxPossible_I
 189   // Else
 190   //    Max_Current_Before_Overflow = Max_Current
 191   // End If
 192   //
 193   // Max_ShuntVoltage = Max_Current_Before_Overflow * RSHUNT
 194   // Max_ShuntVoltage = 0.32V
 195   //
 196   // If Max_ShuntVoltage >= VSHUNT_MAX
 197   //    Max_ShuntVoltage_Before_Overflow = VSHUNT_MAX
 198   // Else
 199   //    Max_ShuntVoltage_Before_Overflow = Max_ShuntVoltage
 200   // End If
 201
 202   // 8. Computer the Maximum Power
 203   // MaximumPower = Max_Current_Before_Overflow * VBUS_MAX
 204   // MaximumPower = 3.2 * 32V
 205   // MaximumPower = 102.4W
 206
 207   // Set multipliers to convert raw current/power values
 208   ina219_currentDivider_mA = 10;  // Current LSB = 100uA per bit (1000/100 = 10)
 209   ina219_powerDivider_mW = 2;     // Power LSB = 1mW per bit (2/1)
 210
 211   // Set Calibration register to 'Cal' calculated above
 212   ina219WriteRegister(INA219_REG_CALIBRATION, 0x1000);
 213
 214   // Set Config register to take into account the settings above
 215   uint16_t config = INA219_CONFIG_BVOLTAGERANGE_32V |
 216                     INA219_CONFIG_GAIN_8_320MV |
 217                     INA219_CONFIG_BADCRES_12BIT |
 218                     INA219_CONFIG_SADCRES_12BIT_1S_532US |
 219                     INA219_CONFIG_MODE_SANDBVOLT_CONTINUOUS;
 220   ina219WriteRegister(INA219_REG_CONFIG, config);
 221 }
 222
 223 /**************************************************************************/
 224 /*!
 225     @brief  Configures to INA219 to be able to measure up to 32V and 1A
 226             of current.  Each unit of current corresponds to 40uA, and each
 227             unit of power corresponds to 800µW. Counter overflow occurs at
 228             1.3A.
 229
 230     @note   These calculations assume a 0.1 ohm resistor is present
 231 */
 232 /**************************************************************************/
 233 void ina219SetCalibration_32V_1A(void)
 234 {
 235   // By default we use a pretty huge range for the input voltage,
 236   // which probably isn't the most appropriate choice for system
 237   // that don't use a lot of power.  But all of the calculations
 238   // are shown below if you want to change the settings.  You will
 239   // also need to change any relevant register settings, such as
 240   // setting the VBUS_MAX to 16V instead of 32V, etc.
 241
 242   // VBUS_MAX = 32V             (Assumes 32V, can also be set to 16V)
 243   // VSHUNT_MAX = 0.32  (Assumes Gain 8, 320mV, can also be 0.16, 0.08, 0.04)
 244   // RSHUNT = 0.1                       (Resistor value in ohms)
 245
 246   // 1. Determine max possible current
 247   // MaxPossible_I = VSHUNT_MAX / RSHUNT
 248   // MaxPossible_I = 3.2A
 249
 250   // 2. Determine max expected current
 251   // MaxExpected_I = 1.0A
 252
 253   // 3. Calculate possible range of LSBs (Min = 15-bit, Max = 12-bit)
 254   // MinimumLSB = MaxExpected_I/32767
 255   // MinimumLSB = 0.0000305             (30.5µA per bit)
 256   // MaximumLSB = MaxExpected_I/4096
 257   // MaximumLSB = 0.000244              (244µA per bit)
 258
 259   // 4. Choose an LSB between the min and max values
 260   //    (Preferrably a roundish number close to MinLSB)
 261   // CurrentLSB = 0.0000400 (40µA per bit)
 262
 263   // 5. Compute the calibration register
 264   // Cal = trunc (0.04096 / (Current_LSB * RSHUNT))
 265   // Cal = 10240 (0x2800)
 266
 267   // 6. Calculate the power LSB
 268   // PowerLSB = 20 * CurrentLSB
 269   // PowerLSB = 0.0008 (800µW per bit)
 270
 271   // 7. Compute the maximum current and shunt voltage values before overflow
 272   //
 273   // Max_Current = Current_LSB * 32767
 274   // Max_Current = 1.31068A before overflow
 275   //
 276   // If Max_Current > Max_Possible_I then
 277   //    Max_Current_Before_Overflow = MaxPossible_I
 278   // Else
 279   //    Max_Current_Before_Overflow = Max_Current
 280   // End If
 281   //
 282   // ... In this case, we're good though since Max_Current is less than MaxPossible_I
 283   //
 284   // Max_ShuntVoltage = Max_Current_Before_Overflow * RSHUNT
 285   // Max_ShuntVoltage = 0.131068V
 286   //
 287   // If Max_ShuntVoltage >= VSHUNT_MAX
 288   //    Max_ShuntVoltage_Before_Overflow = VSHUNT_MAX
 289   // Else
 290   //    Max_ShuntVoltage_Before_Overflow = Max_ShuntVoltage
 291   // End If
 292
 293   // 8. Computer the Maximum Power
 294   // MaximumPower = Max_Current_Before_Overflow * VBUS_MAX
 295   // MaximumPower = 1.31068 * 32V
 296   // MaximumPower = 41.94176W
 297
 298   // Set multipliers to convert raw current/power values
 299   ina219_currentDivider_mA = 25;      // Current LSB = 40uA per bit (1000/40 = 25)
 300   ina219_powerDivider_mW = 1;         // Power LSB = 800µW per bit
 301
 302   // Set Calibration register to 'Cal' calculated above
 303   ina219WriteRegister(INA219_REG_CALIBRATION, 0x2800);
 304
 305   // Set Config register to take into account the settings above
 306   uint16_t config = INA219_CONFIG_BVOLTAGERANGE_32V |
 307                     INA219_CONFIG_GAIN_8_320MV |
 308                     INA219_CONFIG_BADCRES_12BIT |
 309                     INA219_CONFIG_SADCRES_12BIT_1S_532US |
 310                     INA219_CONFIG_MODE_SANDBVOLT_CONTINUOUS;
 311   ina219WriteRegister(INA219_REG_CONFIG, config);
 312 }
 313
 314 /**************************************************************************/
 315 /*!
 316     @brief  Configures to INA219 to be able to measure up to 16V and 500mA
 317             of current.  Each unit of current corresponds to 25uA, and each
 318             unit of power corresponds to 500µW. Counter overflow occurs at
 319             800mA.
 320
 321     @note   These calculations assume a 0.1 ohm resistor is present
 322 */
 323 /**************************************************************************/
 324 void ina219SetCalibration_16V_500mA(void)
 325 {
 326   // VBUS_MAX = 16V
 327   // VSHUNT_MAX = 0.08  (Assumes Gain 2, 80mV, can also be 0.32, 0.16, 0.04)
 328   // RSHUNT = 0.1                       (Resistor value in ohms)
 329
 330   // 1. Determine max possible current
 331   // MaxPossible_I = VSHUNT_MAX / RSHUNT
 332   // MaxPossible_I = 0.8A
 333
 334   // 2. Determine max expected current
 335   // MaxExpected_I = 0.5A
 336
 337   // 3. Calculate possible range of LSBs (Min = 15-bit, Max = 12-bit)
 338   // MinimumLSB = MaxExpected_I/32767
 339   // MinimumLSB = 0.0000153             (15.3µA per bit)
 340   // MaximumLSB = MaxExpected_I/4096
 341   // MaximumLSB = 0.0001221             (122µA per bit)
 342
 343   // 4. Choose an LSB between the min and max values
 344   //    (Preferrably a roundish number close to MinLSB)
 345   // CurrentLSB = 0.0000250 (25µA per bit)
 346
 347   // 5. Compute the calibration register
 348   // Cal = trunc (0.04096 / (Current_LSB * RSHUNT))
 349   // Cal = 16384 (0x4000)
 350
 351   // 6. Calculate the power LSB
 352   // PowerLSB = 20 * CurrentLSB
 353   // PowerLSB = 0.0005 (500µW per bit)
 354
 355   // 7. Compute the maximum current and shunt voltage values before overflow
 356   //
 357   // Max_Current = Current_LSB * 32767
 358   // Max_Current = 0.819175 (819 mA before overflow)
 359   //
 360   // If Max_Current > Max_Possible_I then
 361   //    Max_Current_Before_Overflow = MaxPossible_I
 362   // Else
 363   //    Max_Current_Before_Overflow = Max_Current
 364   // End If
 365   //
 366   // Max_Current_Before_Overflow = 0.8A
 367   //
 368   // Max_ShuntVoltage = Max_Current_Before_Overflow * RSHUNT
 369   // Max_ShuntVoltage = 0.8 * 0.1
 370   // Max_ShuntVoltage = 0.08V
 371   //
 372   // If Max_ShuntVoltage >= VSHUNT_MAX
 373   //    Max_ShuntVoltage_Before_Overflow = VSHUNT_MAX
 374   // Else
 375   //    Max_ShuntVoltage_Before_Overflow = Max_ShuntVoltage
 376   // End If
 377
 378   // 8. Computer the Maximum Power
 379   // MaximumPower = Max_Current_Before_Overflow * VBUS_MAX
 380   // MaximumPower = 0.8 * 16V
 381   // MaximumPower = 12.8W
 382
 383   // Set multipliers to convert raw current/power values
 384   ina219_currentDivider_mA = 40;    // Current LSB = 25uA per bit (1000/25 = 40)
 385   ina219_powerDivider_mW =    1;    // Power LSB = 500µW per bit
 386
 387   // Set Calibration register to 'Cal' calculated above
 388   ina219WriteRegister(INA219_REG_CALIBRATION, 0x4000);
 389
 390   // Set Config register to take into account the settings above
 391   uint16_t config = INA219_CONFIG_BVOLTAGERANGE_16V |
 392                     INA219_CONFIG_GAIN_2_80MV |
 393                     INA219_CONFIG_BADCRES_12BIT |
 394                     INA219_CONFIG_SADCRES_12BIT_1S_532US |
 395                     INA219_CONFIG_MODE_SANDBVOLT_CONTINUOUS;
 396   ina219WriteRegister(INA219_REG_CONFIG, config);
 397 }
 398
 399 /**************************************************************************/
 400 /*!
 401     @brief  Configures to INA219 to be able to measure up to 16V and 200mA
 402             of current.  Each unit of current corresponds to 10uA, and each
 403             unit of power corresponds to 200µW. Counter overflow occurs at
 404             327mA.
 405
 406     @note   These calculations assume a 0.1 ohm resistor is present
 407 */
 408 /**************************************************************************/
 409 void ina219SetCalibration_16V_200mA(void)
 410 {
 411   // VBUS_MAX = 16V
 412   // VSHUNT_MAX = 0.04  (Assumes Gain 1, 40mV, can also be 0.32, 0.16, 0.08)
 413   // RSHUNT = 0.1                       (Resistor value in ohms)
 414
 415   // 1. Determine max possible current
 416   // MaxPossible_I = VSHUNT_MAX / RSHUNT
 417   // MaxPossible_I = 0.4A
 418
 419   // 2. Determine max expected current
 420   // MaxExpected_I = 0.2A
 421
 422   // 3. Calculate possible range of LSBs (Min = 15-bit, Max = 12-bit)
 423   // MinimumLSB = MaxExpected_I/32767
 424   // MinimumLSB = 0.000006104             (6.104µA per bit)
 425   // MaximumLSB = MaxExpected_I/4096
 426   // MaximumLSB = 0,000048828           (48.82µA per bit)
 427
 428   // 4. Choose an LSB between the min and max values
 429   // CurrentLSB = 0.000010 (10µA per bit)
 430
 431   // 5. Compute the calibration register
 432   // Cal = trunc (0.04096 / (Current_LSB * RSHUNT))
 433   // Cal = 40960 (0xA000)
 434
 435   // 6. Calculate the power LSB
 436   // PowerLSB = 20 * CurrentLSB
 437   // PowerLSB = 0.0002 (200µW per bit)
 438
 439   // 7. Compute the maximum current and shunt voltage values before overflow
 440   //
 441   // Max_Current = Current_LSB * 32767
 442   // Max_Current = 0.32767 (328 mA before overflow)
 443   //
 444   // If Max_Current > Max_Possible_I then
 445   //    Max_Current_Before_Overflow = MaxPossible_I
 446   // Else
 447   //    Max_Current_Before_Overflow = Max_Current
 448   // End If
 449   //
 450   // Max_ShuntVoltage = Max_Current_Before_Overflow * RSHUNT
 451   // Max_ShuntVoltage = 0.032767V
 452   //
 453   // If Max_ShuntVoltage >= VSHUNT_MAX
 454   //    Max_ShuntVoltage_Before_Overflow = VSHUNT_MAX
 455   // Else
 456   //    Max_ShuntVoltage_Before_Overflow = Max_ShuntVoltage
 457   // End If
 458
 459   // 8. Computer the Maximum Power
 460   // MaximumPower = Max_Current_Before_Overflow * VBUS_MAX
 461   // MaximumPower = 0.32767 * 16V
 462   // MaximumPower = 5.24W
 463
 464   // Set multipliers to convert raw current/power values
 465   ina219_currentDivider_mA = 100;      // Current LSB = 10uA per bit (1000/10 = 100)
 466   ina219_powerDivider_mW =     1;      // Power LSB = 200µW per bit
 467
 468   // Set Calibration register to 'Cal' calculated above
 469   ina219WriteRegister(INA219_REG_CALIBRATION, 0xA000);
 470
 471   // Set Config register to take into account the settings above
 472   uint16_t config = INA219_CONFIG_BVOLTAGERANGE_16V |
 473                     INA219_CONFIG_GAIN_1_40MV |
 474                     INA219_CONFIG_BADCRES_12BIT |
 475                     INA219_CONFIG_SADCRES_12BIT_1S_532US |
 476                     INA219_CONFIG_MODE_SANDBVOLT_CONTINUOUS;
 477   ina219WriteRegister(INA219_REG_CONFIG, config);
 478 }
 479
 480 /**************************************************************************/
 481 /*!
 482     @brief  Initialises the I2C block
 483 */
 484 /**************************************************************************/
 485 void ina219Init(void)
 486 {
 487   // Reset INA219 (set to default values)
 488   ina219WriteRegister(INA219_REG_CONFIG, INA219_CONFIG_RESET);
 489
 490   // Setup chip for 32V and 2A by default
 491   ina219SetCalibration_32V_2A();
 492 }
 493
 494 /**************************************************************************/
 495 /*!
 496     @brief  Gets the shunt voltage (16-bit signed integer, so +-32767)
 497 */
 498 /**************************************************************************/
 499 int16_t ina219GetShuntVoltage(void)
 500 {
 501   uint16_t value;
 502   ina219Read16(INA219_REG_SHUNTVOLTAGE, &value);
 503   return value;
 504 }
 505
 506 /**************************************************************************/
 507 /*!
 508     @brief  Gets the shunt voltage (16-bit signed integer, so +-32767)
 509 */
 510 /**************************************************************************/
 511 int16_t ina219GetBusVoltage(void)
 512 {
 513   uint16_t value;
 514   ina219Read16(INA219_REG_BUSVOLTAGE, &value);
 515   // Shift to the right 3 to drop CNVR and OVF and then multiply by LSB
 516   return (value >> 3) * 4;
 517 }
 518
 519 /**************************************************************************/
 520 /*!
 521     @brief  Gets the raw power value (16-bit signed integer, so +-32767)
 522 */
 523 /**************************************************************************/
 524 int16_t ina219GetPower(void)
 525 {
 526   uint16_t value;
 527   ina219Read16(INA219_REG_POWER, &value);
 528   return value;
 529 }
 530
 531 /**************************************************************************/
 532 /*!
 533     @brief  Gets the power value in mW, taking into account the config
 534             settings and power LSB
 535 */
 536 /**************************************************************************/
 537 int16_t ina219GetPower_mW(void)
 538 {
 539   uint16_t value;
 540   ina219Read16(INA219_REG_POWER, &value);
 541   return value / ina219_powerDivider_mW;
 542 }
 543
 544 /**************************************************************************/
 545 /*!
 546     @brief  Gets the raw current value (16-bit signed integer, so +-32767)
 547 */
 548 /**************************************************************************/
 549 int16_t ina219GetCurrent(void)
 550 {
 551   uint16_t value;
 552   ina219Read16(INA219_REG_CURRENT, &value);
 553   return value;
 554 }
 555
 556 /**************************************************************************/
 557 /*!
 558     @brief  Gets the current value in mA, taking into account the
 559             config settings and current LSB
 560 */
 561 /**************************************************************************/
 562 int16_t ina219GetCurrent_mA(void)
 563 {
 564   uint16_t value;
 565   ina219Read16(INA219_REG_CURRENT, &value);
 566   return value / ina219_currentDivider_mA;
 567 }
 568
 569