| .. | ||
| .github/workflows | ||
| examples | ||
| test | ||
| .arduino-ci.yml | ||
| INA226.cpp | ||
| INA226.h | ||
| keywords.txt | ||
| library.json | ||
| library.properties | ||
| LICENSE | ||
| README.md | ||
INA226
Arduino library for the INA226 power sensor
Description
Experimental library for the INA226 power sensor. Not all functionality is tested / investigated.
==> USE WITH CARE
The INA226 is a voltage, current and power measurement device. a few important maxima. (See datasheet, ch. 6)
| description | max | unit |
|---|---|---|
| bus voltage | 36 | Volt |
| shunt voltage | 80 | mVolt |
| current | ?? | Ampere |
The sensor can have 16 different I2C addresses, which depends on how the A0 and A1 address lines are connected to the SCL, SDA, GND and VCC pins.
See datasheet - table 2 - datasheet.
TODO: elaborate.
Interface
read datasheet for details
Constructor
- INA226(const int8_t address, TwoWire *wire = Wire) Constructor to set address and optional Wire interface.
- bool begin(const uint8_t sda, const uint8_t scl) for ESP32 and ESP8266; initializes the class. sets I2C pins. Returns true if the INA226 address is on the I2C bus.
- bool begin() UNO ea. initializes the class. returns true if the INA226 address is on the I2C bus.
- bool isConnected() returns true if the INA226 address is on the I2C bus.
Core Functions
Note the power and the current are not meaningful without calibrating the sensor. Also the value is not meaningful if there is no shunt connected.
- float getShuntVoltage() idem.
- float getBusVoltage() idem. Max 36 Volt.
- float getCurrent() is the current through the shunt.
- float getPower() is the current x BusVoltage
Configuration
to be tested.
- void reset() software power on reset
- void setAverage(uint8_t avg = 0) see table below (0 = default ==> 1 read)
- uint8_t getAverage() returns the value set. Note this is not the count of samples.
- void setBusVoltageConversionTime(uint8_t bvct = 4) see table below (4 = default ==> 1.1 ms)
- uint8_t getBusVoltageConversionTime() return the value set. Note this is not a unit of time.
- void setShuntVoltageConversionTime(uint8_t svct = 4) see table below (4 = default ==> 1.1 ms)
- uint8_t getShuntVoltageConversionTime() return the value set. Note this is not a unit of time.
| Average | # samples | notes |
|---|---|---|
| 0 | 1 | default |
| 1 | 4 | |
| 2 | 16 | |
| 3 | 64 | |
| 4 | 128 | |
| 5 | 256 | |
| 6 | 512 | |
| 7 | 1024 |
| BVCT SVCT | time | notes |
|---|---|---|
| 0 | 140 us | |
| 1 | 204 us | |
| 2 | 332 us | |
| 3 | 588 us | |
| 4 | 1.1 ms | default |
| 5 | 2.1 ms | |
| 6 | 4.2 ms | |
| 7 | 8.3 ms |
Note that total conversion time can take up to 1024 * 8.3 ms ~ 10 seconds.
Calibration
See daatsheet, not tested yet.
- void setMaxCurrentShunt(float ampere = 10.0, float ohm = 0.1) set the calibration register based upon the shunt and the max ampere. From this the LSB is derived. Note the function will round up the LSB to nearest round value.
- float getCurrentLSB() returns the LSB == precission of the calibration
Operating mode
See datasheet, partially tested.
Mode = 4 is not used, is also a shutdown() unknown if there is a difference.
- void setMode(uint8_t mode = 7) mode = 0 .. 7
- void shutDown() mode 0 - not tested yet
- void setModeShuntTrigger() mode 1 - not tested yet - how to trigger to be investigated
- void setModeBusTrigger() mode 2 - not tested yet -
- void setModeShuntBusTrigger() mode 3 - not tested yet -
- void setModeShuntContinuous() mode 5
- void setModeBusContinuous() mode 6
- void setModeShuntBusContinuous() mode 7 - default
- uint8_t getMode() returns the mode (0..7) set by one of the functions above.
Alert functions
See datasheet, not tested yet.
- void setAlertRegister(uint16_t mask) by setting the mask one of five an over- or underflow can be detected. Another feature that can be set si the conversion ready flag.
- uint16_t getAlertFlag() returns the mask set by setAlertRegister()
- void setAlertLimit(uint16_t limit) sets the limit that belongs to the chosen Alert Flag
- uint16_t getAlertLimit() returns the limit set by setAlertLimit()
| description alert register | value | a.k.a. |
|---|---|---|
| INA226_SHUNT_OVER_VOLTAGE | 0x8000 | SOL |
| INA226_SHUNT_UNDER_VOLTAGE | 0x4000 | SUL |
| INA226_BUS_OVER_VOLTAGE | 0x2000 | BOL |
| INA226_BUS_UNDER_VOLTAGE | 0x1000 | BUL |
| INA226_POWER_OVER_LIMIT | 0x0800 | POL |
| INA226_CONVERSION_READY | 0x0400 |
| description alert flags | value |
|---|---|
| INA226_ALERT_FUNCTION_FLAG | 0x0010 |
| INA226_CONVERSION_READY_FLAG | 0x0008 |
| INA226_MATH_OVERFLOW_FLAG | 0x0004 |
| INA226_ALERT_POLARITY_FLAG | 0x0002 |
| INA226_ALERT_LATCH_ENABLE_FLAG | 0x0001 |
The alert line falls when alert is reached.
Meta information
- uint16_t getManufacturerID() should return 0x5449
- uint16_t getDieID() should return 0x2260
Operational
See examples..
Not all examples are tested.
TODO
- testtestestest
- improve readme.md