INA220 current/power monitor

Device driver for Texas Instruments INA220 High or Low Side, Bi-Directional CURRENT/POWER MONITOR with Two-Wire Interface.

enum ina220_mode
INA220_MODE_POWERDOWN = 0x0000
Power down.
INA220_MODE_TRIGGER_SHUNT_ONLY = 0x0001
Shunt Voltage, Triggered.
INA220_MODE_TRIGGER_BUS_ONLY = 0x0002
Bus Voltage, Triggered.
INA220_MODE_TRIGGER_SHUNT_BUS = 0x0003
Shunt and Bus, Triggered.
INA220_MODE_ADC_DISABLE = 0x0004
ADC Off (disabled)
INA220_MODE_CONTINUOUS_SHUNT_ONLY = 0x0005
Shunt Voltage, Continuous.
INA220_MODE_CONTINUOUS_BUS_ONLY = 0x0006
Bus Voltage, Continuous.
INA220_MODE_CONTINUOUS_SHUNT_BUS = 0x0007
Shunt and Bus, Continuous, default.
enum ina220_range
INA220_RANGE_40MV = 0x0000
+/- 40 mV range
INA220_RANGE_80MV = 0x0800
+/- 80 mV range
INA220_RANGE_160MV = 0x1000
+/- 160 mV range
INA220_RANGE_320MV = 0x1800
+/- 320 mV range, default
enum ina220_brng
INA220_BRNG_16V_FSR = 0x0000
16 V bus voltage full scale range
INA220_BRNG_32V_FSR = 0x2000
32 V bus voltage full scale range, default.
enum ina220_sadc
INA220_SADC_9BIT = 0x0000
9 bit resolution, 84 us conversion time
INA220_SADC_10BIT = 0x0008
10 bit resolution, 148 us conversion time
INA220_SADC_11BIT = 0x0010
11 bit resolution, 276 us conversion time
INA220_SADC_12BIT = 0x0018
12 bit resolution, 532 us conversion time, default
INA220_SADC_AVG_1_SAMPLE = 0x0040
12 bit resolution, 532 us conversion time, same as INA220_SADC_12BIT
INA220_SADC_AVG_2_SAMPLES = 0x0048
2 sample average, 1.06 ms conversion time
INA220_SADC_AVG_4_SAMPLES = 0x0050
4 sample average, 2.13 ms conversion time
INA220_SADC_AVG_8_SAMPLES = 0x0058
8 sample average, 4.26 ms conversion time
INA220_SADC_AVG_16_SAMPLES = 0x0060
16 sample average, 8.51 ms conversion time
INA220_SADC_AVG_32_SAMPLES = 0x0068
32 sample average, 17.02 ms conversion time
INA220_SADC_AVG_64_SAMPLES = 0x0070
64 sample average, 34.05 ms conversion time
INA220_SADC_AVG_128_SAMPLES = 0x0078
128 sample average, 68.10 ms conversion time
enum ina220_badc
INA220_BADC_9BIT = 0x0000
9 bit resolution, 84 us conversion time
INA220_BADC_10BIT = 0x0080
10 bit resolution, 148 us conversion time
INA220_BADC_11BIT = 0x0100
11 bit resolution, 276 us conversion time
INA220_BADC_12BIT = 0x0180
12 bit resolution, 532 us conversion time, default
INA220_BADC_AVG_1_SAMPLE = 0x0400
12 bit resolution, 532 us conversion time, same as INA220_BADC_12BIT
INA220_BADC_AVG_2_SAMPLES = 0x0480
2 sample average, 1.06 ms conversion time
INA220_BADC_AVG_4_SAMPLES = 0x0500
4 sample average, 2.13 ms conversion time
INA220_BADC_AVG_8_SAMPLES = 0x0580
8 sample average, 4.26 ms conversion time
INA220_BADC_AVG_16_SAMPLES = 0x0600
16 sample average, 8.51 ms conversion time
INA220_BADC_AVG_32_SAMPLES = 0x0680
32 sample average, 17.02 ms conversion time
INA220_BADC_AVG_64_SAMPLES = 0x0700
64 sample average, 34.05 ms conversion time
INA220_BADC_AVG_128_SAMPLES = 0x0780
128 sample average, 68.10 ms conversion time
enum ina220.h::ina220_mode ina220_mode_t

INA220 possible mode settings.

enum ina220.h::ina220_range ina220_range_t

Shunt voltage measurement range (PGA settings)

enum ina220.h::ina220_brng ina220_brng_t

Bus voltage measurement range.

enum ina220.h::ina220_sadc ina220_sadc_t

Shunt ADC settings.

See also

Table 4 in INA220 data sheet

enum ina220.h::ina220_badc ina220_badc_t

Bus ADC settings.

See also

Table 4 in INA220 data sheet

int ina220_init(ina220_t * dev, i2c.h::i2c_t i2c, uint8_t address)

Initialize a current sensor.

Parameters

dev:device descriptor of sensor to initialize
i2c:I2C bus the sensor is connected to
address:I2C slave address of the sensor

Return values

  • 0 on success
  • <0 on error
int ina220_set_calibration(const ina220_t * dev, uint16_t calibration)

Write to calibration register.

Parameters

dev:device descriptor of sensor to configure
calibration:calibration register settings, see data sheet

Return values

  • 0 on success
  • <0 on error
int ina220_set_config(const ina220_t * dev, uint16_t config)

Write to configuration register.

Parameters

dev:device descriptor of sensor to configure
config:configuration register settings, see data sheet

Return values

  • 0 on success
  • <0 on error
int ina220_read_shunt(const ina220_t * dev, int16_t * voltage)

Read shunt voltage.

Parameters

dev:device descriptor of sensor
voltage:measured voltage across shunt resistor

Return values

  • 0 on success
  • <0 on error
int ina220_read_bus(const ina220_t * dev, int16_t * voltage)

Read bus voltage register.

The bus voltage can be found in the most significant bits of the bus voltage register, the lower three bits are flags/reserved.

See the device data sheet for details.

Parameters

dev:device descriptor of sensor
voltage:measured bus voltage

Return values

  • 0 on success
  • <0 on error
int ina220_read_current(const ina220_t * dev, int16_t * current)

Read shunt current.

Parameters

dev:device descriptor of sensor
current:measured current through shunt resistor

Return values

  • 0 on success
  • <0 on error
int ina220_read_power(const ina220_t * dev, int16_t * power)

Read power consumption.

Parameters

dev:device descriptor of sensor
power:measured power consumption

Return values

  • 0 on success
  • <0 on error
INA220_RESET_BIT

INA220 reset command bit (in configuration register) 

1
(0x8000)
INA220_BUS_VOLTAGE_SHIFT

Location of the bus voltage in the INA220 bus voltage register. 

1
(3)
struct ina220_t

Device descriptor for INA220 sensors.

i2c.h::i2c_t i2c

I2C device the sensor is connected to.

uint8_t addr

the slave address of the sensor on the I2C bus