--- /dev/null
+/**************************************************************************/
+/*!
+ @file ina219.c
+ @author K. Townsend (microBuilder.eu)
+
+ @brief Driver for the TI INA219 current/power monitor
+
+ @section DESCRIPTION
+
+ The INA219 is an I2C-based current/power monitor that monitors the
+ voltage drop across a shunt resistor, as well as the supply voltage.
+
+ @section EXAMPLE
+ @code
+ ina219Init();
+
+ int16_t current = 0;
+ int16_t power = 0;
+ int16_t current_mA = 0;
+ int16_t power_mW = 0;
+ int16_t busvoltage = 0;
+ int16_t shuntvoltage = 0;
+ int16_t loadVoltage = 0;
+
+ while(1)
+ {
+ shuntvoltage = ina219GetShuntVoltage();
+ busvoltage = ina219GetBusVoltage();
+ power = ina219GetPower();
+ current = ina219GetCurrent();
+ power_mW = ina219GetPower_mW();
+ current_mA = ina219GetCurrent_mA();
+ loadVoltage = busvoltage + (shuntvoltage / 100);
+ printf("%-15s %6d = %d.%dmV (%duV) \r\n", "Shunt Voltage:", shuntvoltage, shuntvoltage / 100, shuntvoltage % 100, shuntvoltage * 10);
+ printf("%-15s %6d = %d.%dV \r\n", "Bus Voltage:", busvoltage, busvoltage / 1000, busvoltage % 1000);
+ printf("%-15s %6d = %d.%dV \r\n", "Load Voltage:", loadVoltage, loadVoltage / 1000, loadVoltage % 1000);
+ printf("%-15s %6d = %dmW \r\n", "Power:", power, power_mW);
+ printf("%-15s %6d = %dmA \r\n", "Current:", current, current_mA);
+ printf("\r\n");
+ systickDelay(5000);
+ }
+ @endcode
+
+ @section LICENSE
+
+ Software License Agreement (BSD License)
+
+ Copyright (c) 2012 Kevin Townsend
+ 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.
+ 3. Neither the name of the copyright holders nor the
+ names of its contributors may be used to endorse or promote products
+ derived from this software without specific prior written permission.
+
+ THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS ''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 HOLDER 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.
+*/
+/**************************************************************************/
+#include "ina219.h"
+#include "core/systick/systick.h"
+
+extern volatile uint8_t I2CMasterBuffer[I2C_BUFSIZE];
+extern volatile uint8_t I2CSlaveBuffer[I2C_BUFSIZE];
+
+// The following multipliers are used to convert raw current and power
+// values to mA and mW, taking into account the current config settings
+uint32_t ina219_currentDivider_mA = 0;
+uint32_t ina219_powerDivider_mW = 0;
+
+/**************************************************************************/
+/*!
+ @brief Sends a single command byte over I2C
+*/
+/**************************************************************************/
+static void ina219WriteRegister (uint8_t reg, uint16_t value)
+{
+ // Clear write buffers
+ uint32_t i;
+ for ( i = 0; i < I2C_BUFSIZE; i++ )
+ {
+ I2CMasterBuffer[i] = 0x00;
+ }
+
+ I2CWriteLength = 4;
+ I2CReadLength = 0;
+ I2CMasterBuffer[0] = INA219_ADDRESS; // I2C device address
+ I2CMasterBuffer[1] = reg; // Register
+ I2CMasterBuffer[2] = value >> 8; // Upper 8-bits
+ I2CMasterBuffer[3] = value & 0xFF; // Lower 8-bits
+ i2cEngine();
+}
+
+/**************************************************************************/
+/*!
+ @brief Reads a 16 bit values over I2C
+*/
+/**************************************************************************/
+static void ina219Read16(uint8_t reg, uint16_t *value)
+{
+ // Clear write buffers
+ uint32_t i;
+ for ( i = 0; i < I2C_BUFSIZE; i++ )
+ {
+ I2CMasterBuffer[i] = 0x00;
+ }
+
+ I2CWriteLength = 2;
+ I2CReadLength = 2;
+ I2CMasterBuffer[0] = INA219_ADDRESS; // I2C device address
+ I2CMasterBuffer[1] = reg; // Command register
+ // Append address w/read bit
+ I2CMasterBuffer[2] = INA219_ADDRESS | INA219_READ;
+ i2cEngine();
+
+ // Shift values to create properly formed integer
+ *value = ((I2CSlaveBuffer[0] << 8) | I2CSlaveBuffer[1]);
+}
+
+/**************************************************************************/
+/*!
+ @brief Configures to INA219 to be able to measure up to 32V and 2A
+ of current. Each unit of current corresponds to 100uA, and
+ each unit of power corresponds to 2mW. Counter overflow
+ occurs at 3.2A.
+
+ @note These calculations assume a 0.1 ohm resistor is present
+*/
+/**************************************************************************/
+static void ina219SetCalibration_32V_2A(void)
+{
+ // By default we use a pretty huge range for the input voltage,
+ // which probably isn't the most appropriate choice for system
+ // that don't use a lot of power. But all of the calculations
+ // are shown below if you want to change the settings. You will
+ // also need to change any relevant register settings, such as
+ // setting the VBUS_MAX to 16V instead of 32V, etc.
+
+ // VBUS_MAX = 32V (Assumes 32V, can also be set to 16V)
+ // VSHUNT_MAX = 0.32 (Assumes Gain 8, 320mV, can also be 0.16, 0.08, 0.04)
+ // RSHUNT = 0.1 (Resistor value in ohms)
+
+ // 1. Determine max possible current
+ // MaxPossible_I = VSHUNT_MAX / RSHUNT
+ // MaxPossible_I = 3.2A
+
+ // 2. Determine max expected current
+ // MaxExpected_I = 2.0A
+
+ // 3. Calculate possible range of LSBs (Min = 15-bit, Max = 12-bit)
+ // MinimumLSB = MaxExpected_I/32767
+ // MinimumLSB = 0.000061 (61µA per bit)
+ // MaximumLSB = MaxExpected_I/4096
+ // MaximumLSB = 0,000488 (488µA per bit)
+
+ // 4. Choose an LSB between the min and max values
+ // (Preferrably a roundish number close to MinLSB)
+ // CurrentLSB = 0.0001 (100µA per bit)
+
+ // 5. Compute the calibration register
+ // Cal = trunc (0.04096 / (Current_LSB * RSHUNT))
+ // Cal = 4096 (0x1000)
+
+ // 6. Calculate the power LSB
+ // PowerLSB = 20 * CurrentLSB
+ // PowerLSB = 0.002 (2mW per bit)
+
+ // 7. Compute the maximum current and shunt voltage values before overflow
+ //
+ // Max_Current = Current_LSB * 32767
+ // Max_Current = 3.2767A before overflow
+ //
+ // If Max_Current > Max_Possible_I then
+ // Max_Current_Before_Overflow = MaxPossible_I
+ // Else
+ // Max_Current_Before_Overflow = Max_Current
+ // End If
+ //
+ // Max_ShuntVoltage = Max_Current_Before_Overflow * RSHUNT
+ // Max_ShuntVoltage = 0.32V
+ //
+ // If Max_ShuntVoltage >= VSHUNT_MAX
+ // Max_ShuntVoltage_Before_Overflow = VSHUNT_MAX
+ // Else
+ // Max_ShuntVoltage_Before_Overflow = Max_ShuntVoltage
+ // End If
+
+ // 8. Computer the Maximum Power
+ // MaximumPower = Max_Current_Before_Overflow * VBUS_MAX
+ // MaximumPower = 3.2 * 32V
+ // MaximumPower = 102.4W
+
+ // Set multipliers to convert raw current/power values
+ ina219_currentDivider_mA = 10; // Current LSB = 100uA per bit (1000/100 = 10)
+ ina219_powerDivider_mW = 2; // Power LSB = 1mW per bit (2/1)
+
+ // Set Calibration register to 'Cal' calculated above
+ ina219WriteRegister(INA219_REG_CALIBRATION, 0x1000);
+
+ // Set Config register to take into account the settings above
+ uint16_t config = INA219_CONFIG_BVOLTAGERANGE_32V |
+ INA219_CONFIG_GAIN_8_320MV |
+ INA219_CONFIG_BADCRES_12BIT |
+ INA219_CONFIG_SADCRES_12BIT_1S_532US |
+ INA219_CONFIG_MODE_SANDBVOLT_CONTINUOUS;
+ ina219WriteRegister(INA219_REG_CONFIG, config);
+}
+
+/**************************************************************************/
+/*!
+ @brief Configures to INA219 to be able to measure up to 32V and 1A
+ of current. Each unit of current corresponds to 40uA, and each
+ unit of power corresponds to 800µW. Counter overflow occurs at
+ 1.3A.
+
+ @note These calculations assume a 0.1 ohm resistor is present
+*/
+/**************************************************************************/
+static void ina219SetCalibration_32V_1A(void)
+{
+ // By default we use a pretty huge range for the input voltage,
+ // which probably isn't the most appropriate choice for system
+ // that don't use a lot of power. But all of the calculations
+ // are shown below if you want to change the settings. You will
+ // also need to change any relevant register settings, such as
+ // setting the VBUS_MAX to 16V instead of 32V, etc.
+
+ // VBUS_MAX = 32V (Assumes 32V, can also be set to 16V)
+ // VSHUNT_MAX = 0.32 (Assumes Gain 8, 320mV, can also be 0.16, 0.08, 0.04)
+ // RSHUNT = 0.1 (Resistor value in ohms)
+
+ // 1. Determine max possible current
+ // MaxPossible_I = VSHUNT_MAX / RSHUNT
+ // MaxPossible_I = 3.2A
+
+ // 2. Determine max expected current
+ // MaxExpected_I = 1.0A
+
+ // 3. Calculate possible range of LSBs (Min = 15-bit, Max = 12-bit)
+ // MinimumLSB = MaxExpected_I/32767
+ // MinimumLSB = 0.0000305 (30.5µA per bit)
+ // MaximumLSB = MaxExpected_I/4096
+ // MaximumLSB = 0.000244 (244µA per bit)
+
+ // 4. Choose an LSB between the min and max values
+ // (Preferrably a roundish number close to MinLSB)
+ // CurrentLSB = 0.0000400 (40µA per bit)
+
+ // 5. Compute the calibration register
+ // Cal = trunc (0.04096 / (Current_LSB * RSHUNT))
+ // Cal = 10240 (0x2800)
+
+ // 6. Calculate the power LSB
+ // PowerLSB = 20 * CurrentLSB
+ // PowerLSB = 0.0008 (800µW per bit)
+
+ // 7. Compute the maximum current and shunt voltage values before overflow
+ //
+ // Max_Current = Current_LSB * 32767
+ // Max_Current = 1.31068A before overflow
+ //
+ // If Max_Current > Max_Possible_I then
+ // Max_Current_Before_Overflow = MaxPossible_I
+ // Else
+ // Max_Current_Before_Overflow = Max_Current
+ // End If
+ //
+ // ... In this case, we're good though since Max_Current is less than MaxPossible_I
+ //
+ // Max_ShuntVoltage = Max_Current_Before_Overflow * RSHUNT
+ // Max_ShuntVoltage = 0.131068V
+ //
+ // If Max_ShuntVoltage >= VSHUNT_MAX
+ // Max_ShuntVoltage_Before_Overflow = VSHUNT_MAX
+ // Else
+ // Max_ShuntVoltage_Before_Overflow = Max_ShuntVoltage
+ // End If
+
+ // 8. Computer the Maximum Power
+ // MaximumPower = Max_Current_Before_Overflow * VBUS_MAX
+ // MaximumPower = 1.31068 * 32V
+ // MaximumPower = 41.94176W
+
+ // Set multipliers to convert raw current/power values
+ ina219_currentDivider_mA = 25; // Current LSB = 40uA per bit (1000/40 = 25)
+ ina219_powerDivider_mW = 1; // Power LSB = 800µW per bit
+
+ // Set Calibration register to 'Cal' calculated above
+ ina219WriteRegister(INA219_REG_CALIBRATION, 0x2800);
+
+ // Set Config register to take into account the settings above
+ uint16_t config = INA219_CONFIG_BVOLTAGERANGE_32V |
+ INA219_CONFIG_GAIN_8_320MV |
+ INA219_CONFIG_BADCRES_12BIT |
+ INA219_CONFIG_SADCRES_12BIT_1S_532US |
+ INA219_CONFIG_MODE_SANDBVOLT_CONTINUOUS;
+ ina219WriteRegister(INA219_REG_CONFIG, config);
+}
+
+/**************************************************************************/
+/*!
+ @brief Configures to INA219 to be able to measure up to 16V and 500mA
+ of current. Each unit of current corresponds to 25uA, and each
+ unit of power corresponds to 500µW. Counter overflow occurs at
+ 800mA.
+
+ @note These calculations assume a 0.1 ohm resistor is present
+*/
+/**************************************************************************/
+static void ina219SetCalibration_16V_500mA(void)
+{
+ // VBUS_MAX = 16V
+ // VSHUNT_MAX = 0.08 (Assumes Gain 2, 80mV, can also be 0.32, 0.16, 0.04)
+ // RSHUNT = 0.1 (Resistor value in ohms)
+
+ // 1. Determine max possible current
+ // MaxPossible_I = VSHUNT_MAX / RSHUNT
+ // MaxPossible_I = 0.8A
+
+ // 2. Determine max expected current
+ // MaxExpected_I = 0.5A
+
+ // 3. Calculate possible range of LSBs (Min = 15-bit, Max = 12-bit)
+ // MinimumLSB = MaxExpected_I/32767
+ // MinimumLSB = 0.0000153 (15.3µA per bit)
+ // MaximumLSB = MaxExpected_I/4096
+ // MaximumLSB = 0.0001221 (122µA per bit)
+
+ // 4. Choose an LSB between the min and max values
+ // (Preferrably a roundish number close to MinLSB)
+ // CurrentLSB = 0.0000250 (25µA per bit)
+
+ // 5. Compute the calibration register
+ // Cal = trunc (0.04096 / (Current_LSB * RSHUNT))
+ // Cal = 16384 (0x4000)
+
+ // 6. Calculate the power LSB
+ // PowerLSB = 20 * CurrentLSB
+ // PowerLSB = 0.0005 (500µW per bit)
+
+ // 7. Compute the maximum current and shunt voltage values before overflow
+ //
+ // Max_Current = Current_LSB * 32767
+ // Max_Current = 0.819175 (819 mA before overflow)
+ //
+ // If Max_Current > Max_Possible_I then
+ // Max_Current_Before_Overflow = MaxPossible_I
+ // Else
+ // Max_Current_Before_Overflow = Max_Current
+ // End If
+ //
+ // Max_Current_Before_Overflow = 0.8A
+ //
+ // Max_ShuntVoltage = Max_Current_Before_Overflow * RSHUNT
+ // Max_ShuntVoltage = 0.8 * 0.1
+ // Max_ShuntVoltage = 0.08V
+ //
+ // If Max_ShuntVoltage >= VSHUNT_MAX
+ // Max_ShuntVoltage_Before_Overflow = VSHUNT_MAX
+ // Else
+ // Max_ShuntVoltage_Before_Overflow = Max_ShuntVoltage
+ // End If
+
+ // 8. Computer the Maximum Power
+ // MaximumPower = Max_Current_Before_Overflow * VBUS_MAX
+ // MaximumPower = 0.8 * 16V
+ // MaximumPower = 12.8W
+
+ // Set multipliers to convert raw current/power values
+ ina219_currentDivider_mA = 40; // Current LSB = 25uA per bit (1000/25 = 40)
+ ina219_powerDivider_mW = 1; // Power LSB = 500µW per bit
+
+ // Set Calibration register to 'Cal' calculated above
+ ina219WriteRegister(INA219_REG_CALIBRATION, 0x4000);
+
+ // Set Config register to take into account the settings above
+ uint16_t config = INA219_CONFIG_BVOLTAGERANGE_16V |
+ INA219_CONFIG_GAIN_2_80MV |
+ INA219_CONFIG_BADCRES_12BIT |
+ INA219_CONFIG_SADCRES_12BIT_1S_532US |
+ INA219_CONFIG_MODE_SANDBVOLT_CONTINUOUS;
+ ina219WriteRegister(INA219_REG_CONFIG, config);
+}
+
+/**************************************************************************/
+/*!
+ @brief Configures to INA219 to be able to measure up to 16V and 200mA
+ of current. Each unit of current corresponds to 10uA, and each
+ unit of power corresponds to 200µW. Counter overflow occurs at
+ 327mA.
+
+ @note These calculations assume a 0.1 ohm resistor is present
+*/
+/**************************************************************************/
+static void ina219SetCalibration_16V_200mA(void)
+{
+ // VBUS_MAX = 16V
+ // VSHUNT_MAX = 0.04 (Assumes Gain 1, 40mV, can also be 0.32, 0.16, 0.08)
+ // RSHUNT = 0.1 (Resistor value in ohms)
+
+ // 1. Determine max possible current
+ // MaxPossible_I = VSHUNT_MAX / RSHUNT
+ // MaxPossible_I = 0.4A
+
+ // 2. Determine max expected current
+ // MaxExpected_I = 0.2A
+
+ // 3. Calculate possible range of LSBs (Min = 15-bit, Max = 12-bit)
+ // MinimumLSB = MaxExpected_I/32767
+ // MinimumLSB = 0.000006104 (6.104µA per bit)
+ // MaximumLSB = MaxExpected_I/4096
+ // MaximumLSB = 0,000048828 (48.82µA per bit)
+
+ // 4. Choose an LSB between the min and max values
+ // CurrentLSB = 0.000010 (10µA per bit)
+
+ // 5. Compute the calibration register
+ // Cal = trunc (0.04096 / (Current_LSB * RSHUNT))
+ // Cal = 40960 (0xA000)
+
+ // 6. Calculate the power LSB
+ // PowerLSB = 20 * CurrentLSB
+ // PowerLSB = 0.0002 (200µW per bit)
+
+ // 7. Compute the maximum current and shunt voltage values before overflow
+ //
+ // Max_Current = Current_LSB * 32767
+ // Max_Current = 0.32767 (328 mA before overflow)
+ //
+ // If Max_Current > Max_Possible_I then
+ // Max_Current_Before_Overflow = MaxPossible_I
+ // Else
+ // Max_Current_Before_Overflow = Max_Current
+ // End If
+ //
+ // Max_ShuntVoltage = Max_Current_Before_Overflow * RSHUNT
+ // Max_ShuntVoltage = 0.032767V
+ //
+ // If Max_ShuntVoltage >= VSHUNT_MAX
+ // Max_ShuntVoltage_Before_Overflow = VSHUNT_MAX
+ // Else
+ // Max_ShuntVoltage_Before_Overflow = Max_ShuntVoltage
+ // End If
+
+ // 8. Computer the Maximum Power
+ // MaximumPower = Max_Current_Before_Overflow * VBUS_MAX
+ // MaximumPower = 0.32767 * 16V
+ // MaximumPower = 5.24W
+
+ // Set multipliers to convert raw current/power values
+ ina219_currentDivider_mA = 100; // Current LSB = 10uA per bit (1000/10 = 100)
+ ina219_powerDivider_mW = 1; // Power LSB = 200µW per bit
+
+ // Set Calibration register to 'Cal' calculated above
+ ina219WriteRegister(INA219_REG_CALIBRATION, 0xA000);
+
+ // Set Config register to take into account the settings above
+ uint16_t config = INA219_CONFIG_BVOLTAGERANGE_16V |
+ INA219_CONFIG_GAIN_1_40MV |
+ INA219_CONFIG_BADCRES_12BIT |
+ INA219_CONFIG_SADCRES_12BIT_1S_532US |
+ INA219_CONFIG_MODE_SANDBVOLT_CONTINUOUS;
+ ina219WriteRegister(INA219_REG_CONFIG, config);
+}
+
+/**************************************************************************/
+/*!
+ @brief Initialises the I2C block
+*/
+/**************************************************************************/
+void ina219Init(void)
+{
+ // Reset INA219 (set to default values)
+ ina219WriteRegister(INA219_REG_CONFIG, INA219_CONFIG_RESET);
+
+ // Setup chip for 32V and 2A by default
+ ina219SetCalibration_32V_2A();
+}
+
+/**************************************************************************/
+/*!
+ @brief Gets the shunt voltage (16-bit signed integer, so +-32767)
+*/
+/**************************************************************************/
+int16_t ina219GetShuntVoltage(void)
+{
+ uint16_t value;
+ ina219Read16(INA219_REG_SHUNTVOLTAGE, &value);
+ return value;
+}
+
+/**************************************************************************/
+/*!
+ @brief Gets the shunt voltage (16-bit signed integer, so +-32767)
+*/
+/**************************************************************************/
+int16_t ina219GetBusVoltage(void)
+{
+ uint16_t value;
+ ina219Read16(INA219_REG_BUSVOLTAGE, &value);
+ // Shift to the right 3 to drop CNVR and OVF and then multiply by LSB
+ return (value >> 3) * 4;
+}
+
+/**************************************************************************/
+/*!
+ @brief Gets the raw power value (16-bit signed integer, so +-32767)
+*/
+/**************************************************************************/
+int16_t ina219GetPower(void)
+{
+ uint16_t value;
+ ina219Read16(INA219_REG_POWER, &value);
+ return value;
+}
+
+/**************************************************************************/
+/*!
+ @brief Gets the power value in mW, taking into account the config
+ settings and power LSB
+*/
+/**************************************************************************/
+int16_t ina219GetPower_mW(void)
+{
+ uint16_t value;
+ ina219Read16(INA219_REG_POWER, &value);
+ return value / ina219_powerDivider_mW;
+}
+
+/**************************************************************************/
+/*!
+ @brief Gets the raw current value (16-bit signed integer, so +-32767)
+*/
+/**************************************************************************/
+int16_t ina219GetCurrent(void)
+{
+ uint16_t value;
+ ina219Read16(INA219_REG_CURRENT, &value);
+ return value;
+}
+
+/**************************************************************************/
+/*!
+ @brief Gets the current value in mA, taking into account the
+ config settings and current LSB
+*/
+/**************************************************************************/
+int16_t ina219GetCurrent_mA(void)
+{
+ uint16_t value;
+ ina219Read16(INA219_REG_CURRENT, &value);
+ return value / ina219_currentDivider_mA;
+}
+
+
projects / hackover2013-badge-firmware.git / blobdiff